The Project Gutenberg eBook of Cooley’s Cyclopædia, 6th Ed., Vol. I, by Arnold James Cooley.

Some one has said that “when a book reaches a fifth edition it scarcely requires a preface.” If such be true of a fifth, it is probably still truer of a sixth edition, and therefore this issue of ‘Cooley’s Cyclopædia’ might fairly be sent forth to the public without any prefatory remarks whatever. It is, however, desirable to point out that the present edition is larger than the last by about six hundred pages; that much greater space than hitherto is devoted to Hygiène (including sanitation, the composition and adulteration of foods) as well as to the Arts, Pharmacy, Manufacturing Chemistry, and other subjects of importance to those for whom the work is intended.

The articles on what is commonly termed ‘Household Medicine’ have been amplified and numerically increased.

Short accounts of the more common diseases, their causes, symptoms, and treatment, affecting the domesticated animals have been introduced. “Here, however, it may be useful to repeat the cautions given in other parts of this volume, as to the impropriety of unnecessarily meddling with the healing art or neglecting a prompt application” (where and when possible) “to a duly qualified practitioner in all cases demanding medical or surgical aid.” These remarks of Mr Cooley are as applicable to cases of Veterinary as to those of Human Medicine.

Numerous authors have necessarily been consulted; a list of them, and the titles of their works from which information has been derived, will be found at the end of the second volume. When extracts have been introduced verbatim the authority is quoted in the body of the book.

Many of my scientific confrères have rendered me valuable aid in preparing this edition; but I am particularly indebted to my accomplished and zealous friend Mr John Gardner for his hearty and constant co-operation; to Dr Lionel Beale for his kindness in revising the articles on “Urine,” “Urinary Diseases,” &c., as well as for thevi use of cuts from his celebrated works on these subjects; to my friend and former pupil Mr F. Woodland Toms for revising and rewriting the articles on “Sewage” and “Water;” and to my assistants Mr James Bayne and Mr Cuthbert Neison for correcting “proof.”

The laborious task of preparing a sixth edition of ‘Cooley’ having been accomplished, it is hoped that, due consideration being given to the magnitude of the work and to the great variety of the subjects treated, it will be found to be practically free from important errors, and that it will meet with, at least, the same gratifying reception as that accorded to its predecessors.

PREFACE

The design of the present work is briefly, but not completely expressed in its title-page. Independently of a reliable and comprehensive collection of formulæ and processes in nearly all the industrial and useful arts, it contains a description of the leading properties and applications of the substances referred to, together with ample directions, hints, data, and allied information, calculated to facilitate the development of the practical value of the book in the shop, the laboratory, the factory, and the household. Notices of the substances embraced in the Materia Medica of our national pharmacopœias, in addition to the whole of their preparations, and numerous other animal and vegetable substances employed in medicine, as well as most of those used for food, clothing, and fuel, with their economic applications, have been included in the work. The synonymes and references are other additions which will prove invaluable to the reader. Lastly, there have been appended to all the principal articles referred to brief, but clear, directions for determining their purity and commercial value, and for detecting their presence and proportions in compounds.

The sources from which I have derived the vast mass of materials forming this volume are such as to render it deserving the utmost confidence. I have invariably resorted to the best and latest authorities, and have consulted almost innumerable volumes, both British and foreign, during its compilation. Secondary channels of information have been scarcely ever relied on when original authorities were within my reach. A large portion of the work has been derived from my personal experience and observations in the departments of applied chemistry and hygiene, and from the processes of various laboratories and manufactories, many of which I can the more confidently recommend from having either inspected or witnessed their employment on an extensive scale. The indiscriminate adoption of matter, without examination, has been uniformly avoided, and in no instance has any formula or process been admitted into this work, unless it rested on some well-known fact of science, had been sanctioned by usage, or come recommended by some respectable authority. The settlement of doubtful or disputed pointsviii has often occupied me a greater number of hours, and not unfrequently a greater number of days, than that of the lines of letter-press which convey the results to the public. In all cases precedence has been given to the standard formulæ of our national pharmacopœias, and to those processes which long experience, or well-conducted experiments, have shown to be the most successful, profitable, and trustworthy. In general, the sources of information have been indicated, for the purpose of enabling the reader to form a better estimation of their value. Whenever this is not the case, in reference to borrowed formulæ and data, the omission has arisen from the impossibility of determining to whom the merit is justly due.

I have endeavoured as much as possible, in the present work, to avoid confusion of the medical weights with those commonly used in trade and commerce—an attempt which, so far as I am aware, has not been successfully carried out in any other quarter. For this purpose I determined to entirely abandon the usual arbitrary signs or characters employed to represent the divisions of the apothecaries’ pound, and to distinguish the two weights from each other, by simply printing, in different type, the plain English names and abbreviations representing their several denominations. The medical signs for the imperial gallon and its subdivisions have also been abandoned for their common English names. It would have afforded me pleasure to have reduced all the quantities to one uniform standard, had it been practicable, or, in all cases, advisable.

Under the names of most of the leading diseases that could be profitably noticed in the present work, such explanations and directions have been given as accord with the prevailing opinions and practice of the faculty at the present day. These, when judiciously applied, will prove invaluable to emigrants, travellers, voyagers, and other parties beyond the reach of legitimate medical assistance; and, under opposite circumstances, will, in general, enable those who have the care of the sick the better to second and carry out the instructions and efforts of the physician for the benefit of their charge. Here, however, it may be useful to repeat the cautions given in other parts of this volume, as to the impropriety of unnecessarily meddling with the healing art, or neglecting a prompt application to a duly qualified practitioner, in all cases demanding either medical or surgical aid. It is an indubitable fact that the best efforts of the inexperienced and uninitiated in the mysteries of medical science must be always enormously behind those of parties whose whole lives and study have been devoted to the subject.

The nature of a condensed alphabetical arrangement not permittingix numerous articles to come under distinct heads, or to be referred to under all their synonymes, the casual reader may often be led to suppose that this book is most deficient where in reality it is the most copious. In general I have attempted, as much as possible, to bring together subjects of a closely allied character, and compounds which are analogous to each other, either in constitution or the mode of their preparation. Thus, most of the formulæ for Mixtures, Ointments, Pills, &c., follow in alphabetical order the general articles under these heads; whilst those for the Oxides, Salts, &c., follow the names of their respective bases. In like manner, a notice of a number of preparations will be found included in that of their principal ingredients. The names under which the leading substances appear are generally those which are most familiar to well-informed practical men, and which have commonly reference to either their acknowledged chemical constitution, or to some long-known and easily recognised quality. The following extract conveys an important lesson on this subject, with which I perfectly agree:—“We have been unwilling to make any unnecessary changes in the nomenclature of substances whose names are sanctioned by the usage of the present day; for these names have been, for the most part, rightly assigned by our predecessors, or confirmed by lapse of time. We are indeed aware that every improvement in the knowledge of things ought to be embodied in their names; but we must be careful, in selecting or forming these names, not to make those points appear certain and established which are as yet doubtful, for it is safer to be in the rear than advance of natural history.”[1]

I have exerted myself to the utmost to ensure the accuracy and completeness of this volume, but I feel conscious that, after all my efforts for this purpose, some errors have crept into it, that many subjects which deserve insertion in it have been omitted, and that many others have been either imperfectly or too briefly noticed. “Yet these failures, however frequent, may,” I trust, “admit of extenuation and apology. To have attempted much is always laudable, even where the enterprise is above the strength that undertakes it. To rest below his aim is incident to every one whose fancy is active, and whose views are comprehensive; nor is any man satisfied with himself because he has done much, but because he conceives little.” When I commenced this work I resolved to leave nothing within its legitimate limits unexamined or unelucidated; and I flattered myself with a prospect of the hours which I should thus “revel away” in a pursuit so congenial to my desires—“the treasures with which I expected every search into those neglected mines to reward my labour—and the triumph with which I should display my acquisitions to mankind.” But these were thex dreams of a poet, doomed at last to wake a “Cyclopædist”. The long task which I had undertaken soon exhibited its truly onerous character, and daily grew in urgency, until that which promised to be a pleasure had been transformed into an exhausting and continuous labour. At first, a sacrifice of the hours of leisure only seemed necessary to the undertaking—next, those assigned to professional and business avocations were demanded, and absorbed; but, ere long, one by one, the hours usually devoted to repose were sucked into the insatiable vortex, until the bright beams of the rising sun not unfrequently illumined the lamp-lit study or the gloomy laboratory, and surprised the author, no longer an enthusiast, at his still-enduring task. But long ere this I had learned that to carry out my original resolutions in all their completeness and entirety was impossible, and “that to pursue perfection was, like the first inhabitants of Arcadia, to chase the sun, which, when they had reached the hill where he had seemed to rest, was still at the same distance from them.”[2] All I can further say in reference to this point is simply to assure the reader that three of the elements usually deemed essential to give value to a technological work—viz. zeal, industry, and capital—have not been wanting in the production of the present one;—the first two depending on the author, and the other chiefly on the liberality and enterprise of the publisher.

As heretofore, I beg to solicit my readers to apprise me of any inaccuracies or omissions in this volume which may come beneath their notice. I shall also thankfully receive any hints or suggestions tending to the improvement of future editions of this work. Such communications, to be useful, must, however be written on only one side of the paper. Parties who may thus kindly afford me assistance will, in due course, have their services publicly acknowledged; and their names and addresses, unless when otherwise requested, will be published in full.

I have endeavoured to render the present volume as self-explanatory as possible, and, in general, have appended ample directions to the several formulæ and processes that seemed to me likely to cause embarrassment to those inexpert in chemical manipulation; but should any party find it otherwise, I shall be happy to reply, gratuitously, to any reasonable questions tending to elucidate the difficulty.

In conclusion, I may add that, having now for nearly a quarter of a century devoted my attention to the applications of chemistry in most of the useful arts and manufactures, both British and foreign, and in sanitation, I am in possession of many valuable processes and formulæ, hitherto wholly unknown, or but partially developed, with variousxi improved plans of factories, laboratories, ventilation, &c., which the limits of this work will not permit me to describe in its pages, but on which I should be happy to communicate with parties interested in the same. Persons desirous of establishing any new branch of manufacture, or of improving an existing one, or of determining the purity or value of articles of food, wines, liqueurs, medicines, &c., or of obtaining formulæ or processes which are not contained in this work, may, in like manner, have their wishes complied with, by enclosing to me samples, or the requisite information.

NAMES OF THOSE WHO HAVE CONTRIBUTED TO, OR ASSISTED IN THE REVISION OF, THIS EDITION

ABBREVIATIONS, ETC., USED IN THIS WORK

These, for the most part, consist of the first syllable, or the initial letter or letters of the words they stand for. As Prep., preparation; Pur., purity; Purif., purification; Obs., observations; Var., varieties, &c.—Ph., stands for pharmacopœia; B. P., for British Pharmacopœia; Ind. Ph., for Indian Pharmacopœia; Cod., for Codex.—L., E., D., P., U. S., &c., associated with the last two abbreviations, are the initial letters of the cities and countries which produced the respective works; as, London, Edinburgh, Dublin, Paris, United States, &c. When no dates are given, the last editions of the pharmacopœias are referred to.

lb., oz., dr., respectively represent the pound, ounce, and drachm (¹⁄₈ oz.), Avoirdupois weight. This is the only weight employed in the British and last Dublin Pharmacopœias.

lb., oz., dr., and gr., refer to the pound, ounce, drachm, and grain, Apothecaries’ or Troy weight.

The names of individuals which appear in this work are those to whom the immediately attached information or formula is usually attributed, or on whose recommendation or authority it has been selected.

A CYCLOPÆDIA
OF
PRACTICAL RECEIPTS, PROCESSES,
AND
COLLATERAL INFORMATION

A-, ab-, abs-. [L.] In composition, from, denoting distance, departure, separation, or opposition; as in aberration, abstraction, abnormal, &c.

A-, an-. [Gr.] In composition, no, not, without, denoting the absence or loss of some quality or thing; as in achromatic, anhydrous, amorphous, &c.

AB′ACA (kăh). A species of vegetable fibre, of several varieties, obtained in the Philippine Islands, and remarkable for its brilliancy, strength, and durability. The finer kinds are woven into muslins, and other delicate fabrics; the coarser are formed into mats, cordage, and sail-cloth. It has been recently employed in Paris for the manufacture of various articles of furniture and dress; including bonnets, tapestry, carpets, network, hammocks, &c. The fibre, and fabrics made of it, may be bleached and dyed in a similar manner to flax and linen.

ABATTOIR. A public slaughter-house for cattle, &c., usually erected within the walls or precincts of a continental town or city.

ABBREVIATION. One or more of the earlier letters of a word used to express the whole.

Ad 2 vic., ad secundum vicem, to the second time; or ad duas vices, for two times.

Add., adde, or addantur, add, or let them be added; addendus, to be added.

Admov., admove, admoveatur, admoveantur, apply, let it be applied, let them be applied.

C. C., cornu cervi, hartshorn; it may also signify cucurbitula cruenta, the cupping-glass with scarificator.

Coch. ampl., cochleare amplum, a large (or table) spoonful; about half a fluid ounce.

Coch. mod., cochleare modicum,} a dessert-spoonful—about two fluid drachms.

Coch. parv., cochleare parvum, a small (or tea) spoonful; it contains about one fluid drachm.

Colet., coletur, colat., colatur, let it be strained; colaturæ, to the strained liquor.

Cont. rem., or med., continuentur remedia, or medicamenta, let the remedies, or the medicines, be continued.

Coq. ad med. consumpt., coque or coquatur ad medietatis consumptionem, boil, or let it be boiled to the consumption of one half.

Coq. in S. A., coque in sufficiente quantitate aquæ, boil in a sufficient quantity of water.5

D. in p. æq., dividatur in partes æquales, let it be divided in equal parts.

Donec alv. bis dej., donec alvus bis dejecerit, until the bowels have been twice opened.

Donec alv. sol. fuer., donec alvus soluta fuerit, until the bowels have been loosened.

Donec dol. neph. exulav., donec dolor nephriticus exulaverit, until the nephritic pain has been removed.

Ext. sup. alut. moll., extende super alutam mollem, spread upon soft leather.

Har. pil. sum. iij, harum pilularum sumantur tres, of these pills let three be taken.

M., misce, mix; mensurâ, by measure; manipulus, a handful; minimum, a minim.

Mitt. sang. ad ℥xij, mitte sanguinem ad ℥xij, take blood to twelve ounces.

Per. op. emet., peractâ operatione emetici, the operation of the emetic being over.

Post sing. sed. liq., post singulas sedes liquidas, after every loose stool.

Pug., pugillus, a pinch, a gripe between the thumb and the two first fingers.

Sign. n. pr., signetur nomine proprio, let it be written upon, let it be signed with the proper name (not the trade name).

Sub fin. coct., sub finem coctionis, towards the end of boiling, when the boiling is nearly finished.

Sum., sume, sumat, sumatur, sumantur, take, let him or her take, let it be taken, let them be taken.

ABDO′MEN. [Eng., Fr., L.] In anatomy, the belly, or lower belly; the great cavity of the body extending from the thorax, or chest, to the bottom of the pelvis. It contains the stomach, intestines, liver, spleen, kidneys, bladder, &c.; and in the female, the uterus, ovaria. &c.

AB′ERNE′THY MEDICINES. These originally consisted of a calomel pill, and subsequently of a mercurial or ‘blue’ pill, to be taken over-night, followed by an aromatised black draught in the morning. The quantity of either of the former, for an adult, was about 3 gr. to 3¹⁄₂ gr., increased a little in bulk by the addition of some liquorice powder; that of the latter, from 1 to 1¹⁄₂ fl. oz. As, however, when frequently taken, these pills sometimes occasioned salivation, which proved prejudicial to their sale, a little compound extract of colocynth (Ph. L., 1836) was introduced into their composition, by which this objection was obviated. Ultimately, their composition was settled at 3 gr. of mercurial pill, and 2 gr. of compound extract of colocynth; and these proportions are still followed as the best by those who prepare and sell them.7 Persons who object to black draught, will find a dose of castor oil, or of any other mild purgative medicine that may be more agreeable to them, equally efficacious.

The occasional use of these medicines seldom fails to prove highly beneficial to the plethoric, bilious, and dyspeptic. In ordinary cases of constipation, headache, &c., arising from deranged stomach or liver, wherein the administration of mercurials is not contra-indicated, they will be found of great service. It need scarcely be added that these medicines are named after Mr Abernethy, the celebrated surgeon, who is said to have frequently employed them in his practice.

ABERRA′TION. [Eng., Fr.] Syn. Aberra′tio, L. A wandering or deviation from the usual course, or from the normal condition. In optics, the deviation of the rays of light from the true focus, when inflected by a lens or speculum. This arises from a difference in the physical nature of the rays, from the figure of the lenses or specula, or from the nature of the materials of which the media traversed are composed. See Achromatism, Lens, &c.

Aberration of mind. Mental alienation or wandering; insanity. A term frequently applied, in familiar language, to a mild form of incipient insanity or dementia, which is more or less occasional or continued, trifling or severe, according to circumstances. The studious, nervous, slothful, and those who are engaged in sedentary occupations and spend much of their time in ill-ventilated apartments, or who indulge in irregular or vicious habits, as well as ‘fast livers,’ are the most liable to this affection. It also frequently arises from disordered physical health.

Treat., &c. Change of scene, out-door exercise, agreeable company, pleasing and continued mental occupation, and due attention to diet, clothing, ventilation, &c., with the judicious use of some mild aperient medicine and tepid bathing, will generally alleviate, and frequently effect a cure. For the prevention of its accession, or its recurrence, care should be taken to promote the general health, and also, where necessary, to elevate the spirits and to divert the mind.

ABLU′TION. [Eng., Fr.] Syn. Ablu′tio, L. In a general sense, washing, cleansing, or purification by water.

Ablution. In hygiène and the toilet, a washing of the whole body, or any part of it. The value of frequent and copious affusions of pure water to the surface of the body is well known. During life, the skin is continually subjected to abrasion, and the processes of reproduction and decay, by which the cuticle, its exterior portion, is being constantly thrown off as effete and useless matter, in the shape of very minute scales or dust. This, mingling with the oily and saline products of the skin, acquires sufficient adhesiveness to attach itself to the surface of the body and clothing, as well as to attract the waste particles of the dress, and the dust and soot floating in the atmosphere. In this way, if occasional ablutions be not had recourse to, the channels of perspiration will become choked, and the clothing itself rendered unwholesome and unfit for use. The consequence of the pores of the skin being obstructed is impeded transpiration, by which its functions, as a respiratory organ, are interfered with or suspended. This adhering pellicle of refuse matter also acts as an irritant, and forms a favorable medium for the absorption, and the transmission into the body, of effluvia, miasmata, poisonous gases, and the infectious and contagious matters of disease. “The greater part of (contagious) poisons are conveyed to us through the external surface of our bodies; and it is fully proved that poison, already communicated, has been by cleanliness removed, before it could actually produce any bad effects. I here allude, in particular, to frequent washing, bathing, rinsing the mouth, combing and brushing the hair, and often changing the linen, clothing, and bedding.” (Hufeland.) Such are the immediate effects of neglected ablution of the skin; the further consequences are of an equally serious character. The blood being deprived of one of its sources of oxygen, and one of the outlets for its carbon, the functions of nutrition become imperfect, and the animal temperature lessened. The matters which would be thrown out of the system in the form of perspiration are retained, and must be eliminated by other channels. The lungs, the kidneys, the liver, and the bowels, are each, in their turn, overtasked to perform the functions of another organ. The oppressed viscera suffer from exhaustion, and incipient disease soon follows. Their particular offices are languidly performed, the equilibrium of health is disturbed, and skin diseases, or consumption, diarrhœa, dropsy, liver-complaints, visceral obesity, or some other serious diseases of the vital organs, ensue. When it is added, that no dirty or imperfectly washed skin can long continue healthy, and ceasing to be healthy must also cease to be agreeable and beautiful, the argument in favour of the daily use of water of good quality to the whole surface of the body, when possible, will surely be complete. The inculcation of habits of personal cleanliness cannot be too forcibly emphasized. The fact, however, cannot be overlooked, that in order to introduce habits of cleanliness amongst the poorer classes, a plentiful supply of water, combined with cheap baths, are requisite. Every officer of health should inquire into the amount as well as the character of the water supply in the district over which he has supervision. The body should be washed all over every morning with either cold or lukewarm water and soap. This custom is more necessary for workmen employed in laborious and dirty occupations than for those who live sedentary lives; but all people8 perspire, and from every drop of perspiration the water evaporates, and leaves a fraction of solid matter on and around the pores that excrete the perspiration. If this solid matter be not washed off, it accumulates and may derange the health. Instances have occurred in which persons suffering from extensive bodily burns have died, not from the effect of the injury, but from the destruction of the pores or excreting vessels, with which the skin is covered. It is well, therefore, to bear in mind that a dirty skin does not always come from without, but also from within. Cold ablution, that has been so indiscriminately recommended, is not half so efficacious, nor so safe, as lukewarm. The German aurists ascribe the presence of the large amount of deafness in England to our habit of washing the head and ears each morning with cold water.

Ablution. In medicine, the washing the body, externally, as by bathing; or internally, by diluting drinks. In ancient medicine, according to Galen, internal ablution was accomplished by the use of profuse libations of milk-whey; an object now aimed at, by the hydropathists, by the copious administration of pure cold water. To neglect the daily ablution of an infant is to discard one of the greatest aids to its healthy development and physical wellbeing. That disregard of this precaution is a fertile source of most of the skin diseases that affect infants and children there seems little question about amongst medical men. Water at a temperature ranging from 80° to 90° F. should always be used. Mr Chevasse, in his ‘Counsel to a Mother,’ is emphatic in his advocacy of rain water. He also advises the employment of Castile soap, and of glycerine soap, should there be any excoriation of the skin. Of course the same remarks apply to children as to infants, with this difference, that the ablution is to be performed with water a few degrees colder; and both infants and children should be rubbed dry with a dry soft towel. There are doubtless many persons who deem themselves cleanly washed, if in addition to their hands and arms, neck and face, undergoing duly daily ablution, they wash their feet once a week. These individuals cannot reflect that, because of their less exposure to the depurating influence of the atmosphere, the feet require to be more frequently washed than either the hands or face. See Bathing, Baths, Hydropathy, &c.

ABNORM′AL. [Eng., Fr.] Syn. Abnor′mis, L. In medicine and the collateral sciences, contrary to, or without system or rule; irregular; deformed; unnatural. In a diseased or unhealthy state.

ABORTION IN COWS. Abortion is the expulsion of the contents of the pregnant womb before the full period of gestation is complete, and occurs much more frequently in cows than in any other of the lower animals. Abortion is often induced by shocks and injuries, feeding on ergotised grasses, but more commonly by causes which are less obvious. Thus, bad smells, pasturing on flooded meadows, rich and stimulating food, and even association with other cows while aborting, are among the exciting causes of this malady. The premonitory signs are an irritable excited state of the animal, a discharge from the vagina, looseness and fulness of the external organs of generation, and, occasionally, sudden enlargement of the udder. These symptoms may continue for several days, and, if noticed before straining or other signs of calving have appeared, the animal should be copiously bled and placed in a comfortable loose-box, kept as quiet as possible, moderately supplied with soft laxative food, and, if the bowels be costive, with a pound or two of treacle daily. Powerful purgatives are too irritant, and must, therefore, be studiously avoided. Two ounces of laudanum, with the same quantity of sweet spirits of nitre, should be given twice a day until all danger is over. To prevent the continuance and spread of the evil, place the cow by herself as soon as she aborts; remove and bury the fœtus beyond the reach of other cows; feed off the cow, if practicable, but if she be again bulled, it ought not to be for several weeks, and until the period of heat is passing off; remove all disagreeable smells, and see that the remainder of the herd are moderately fed and carefully watched, so that the earliest symptoms of abortion may be noticed.

ABRA′SION. [Eng., Fr.] Syn. Abra′sio, L. The rubbing or wearing down of surfaces by friction. In the arts, the reduction or figuration of materials by the use of an abrasive tool, or grinder, of which the effective portion is an exact counterpart of the form to be produced.

Abrasion. In numismatics, the ‘wear and tear,’ or waste of the substance of coins, in the pocket and circulation. It forms a large item in the expense of a metallic currency. The means employed to obviate, or to reduce it, consist in either alloying the metal to render it tougher and harder, or raising the borders so as to lessen the surface exposed to friction. In well-formed coin both methods are adopted.

Abrasion. In pathology and surgery—1. A superficial removal or injury of the skin by fretting or friction.

Treat., &c. When the injured surface is large, or exposed, it should be protected from dirt and further injury, by applying a piece of lint or soft linen rag, covered with spermaceti cerate, or some other simple ointment; over which a piece of strapping, or bandage of any sort, may be placed to keep it on. In many cases, a piece of common sticking-plaster will be found quite sufficient.

2. A very superficial ulceration or excoriation of the intestinal or other mucous membrane. Treat. Aperients of castor oil, demulcents,9 and a light nutritious diet. See Excoriations.

ABRUS PRECATORIUS. (Ind. Ph.) Indian Liquorice Plant. Habitat. Tropical portions of both hemispheres, Officinal part. The root (Abri Radix, Indian Liquorice). Occurs in pieces of various lengths, from ¹⁄₂ to 1 inch in diameter; pale brown externally, yellowish internally; inodorous, taste sweetish and mucilaginous, much resembling officinal liquorice root. Properties and uses. Similar to those of liquorice, for which it forms an excellent substitute. Preparation. Extract of Abrus (Extractum Abri). Prepared as Extractum Glycyrrhizæ.

ABSCESS. A formation of matter or pus, resulting from inflammation, either acute or chronic. The symptoms are pain, swelling, heat, and redness, a conical projection on the swelling, often with a white point at the apex. Abscess or suppuration may come on any part of the body. When the local inflammation does not yield to cold lotions, apply poultices; a pledget of lint dipped in cold water and kept moist by means of oil-silk; a slice of bread softened with boiling water or milk, or linseed meal, make the best poultices. Should the pain be severe add laudanum, and additionally rub it round the swelling. Or apply common white paint by laying it on gently with a brush, or else tincture of marigold or arnica in the same manner. Chronic abscesses in the glands in the neck are usually scrofulous, and should be opened. Abscesses in the breast should not be opened too early, or others are formed. Those in the gums may be cut early, not so if in the tonsils. After opening with a needle or lancet-point external abscesses, continue to poultice till the hardness disappears, then dress with spermaceti ointment spread on lint. When the abscess is of a dangerous nature, lose no time in consulting a medical practitioner.

Treatment for horses and cattle. Mr Finlay Dun prescribes fomentations, poultices, counter-irritants, the knife, cauterisation, carbolic-acid dressing, stimulating injections, and the administration of sulphites and chlorate of potash.

ABSINTHE. [Fr.] Absinthium, L.; Wormwood, E.; Wermuth, G. This article is met with in commerce in the form of the dried herb with the flowers of Artemisia Absinthium, having a whitish-grey appearance, a soft feel, an aromatic and unpleasant odour, and an extremely bitter and aromatic flavour. The plant is indigenous, and grows in thickets, in mountainous districts, and on waste ground. Its odour is due to its containing an essential oil; its bitterness is referable to absinthin, a crystallisable principle which may be extracted from the herb by water or spirit. The name absinthe is also given to an intoxicating liqueur which is extensively drunk on the Continent, and which unfortunately appears to be rapidly attracting consumers in this country. The remarks on this subject by Blyth in his admirable ‘Dictionary of Hygiène’ are so pregnant with important facts that they will be here produced verbatim et literatim. “An analysis recently made at the Conservatoire des Arts shows that absinthe now contains a large quantity of antimony, a poison which cannot fail to add largely to the irritant effects necessarily produced on the alimentary canal and liver by constant doses of a concentrated alcoholic liquid. And we have recently received the results of some experiments made by M. Magnan, of Paris. By means of successive distillations he has been able to isolate various products—(1) a blue oil; (2) a yellowish oil; (3) an oxygenated substance. There was besides a yellowish residue left in the glass. These various substances were tried on animals; ten grammes of the yellow sediment given to a small dog produced no effect; thirty centigrammes of the blue oil produced from eight to ten epileptiform attacks. The oxygenated product proved, however, the most powerful toxic agent. Fifteen centigrammes of it, injected into the veins of a large dog, caused the most violent epileptic attacks, which followed in rapid succession, and ended in death. There was an extraordinary rise of temperature, from 39° to 42° Centigrade, and the post mortem showed various apoplectic centres. Dr Decaisne regards the terrible evil of this almost universal absinthe-drinking as the greatest national calamity that has ever befallen France, and has made an eloquent appeal to the Government to strike at once a decisive blow at the trade in this liqueur. Originally the only important ingredient in its composition besides alcohol was the essential oil of absinthium or wormwood; and though this without doubt added something to the mischievous effects of the liqueur, it would be impossible to trace to it, or to the other comparatively trivial ingredients, the more serious of the special results which are now observed to occur to victims of absinthe, though the habitual drinking even in small doses of good absinthe is believed by Dr Decaisne, sooner or later, to produce disorders in the animal economy. Now various deleterious substances are added, the most important of these being antimony. As at present constituted, therefore, and especially when drunk in the disastrous excess now common in Paris, and taken, as it frequently is, on an empty stomach, absinthe forms a chronic poison of almost unequalled virulence, both as an irritant to the stomach and bowels, and also as a destroyer of the nervous system. The effect of absinthe is to produce a superabundant activity of the brain, a cerebral excitement, which at first is agreeable; intoxication comes on rapidly; the head swims, and the effect produced is nearly the same as that of poisoning by a narcotic, which certainly does not occur with an equal dose of brandy. With the absinthe-drinker,10 as with the opium-eater, the excitement the spirit produces diminishes daily in intensity. Each day he is obliged to augment the dose in order to bring himself up to the right pitch. The diseases brought on by the excessive drinking of ardent spirits are produced with greater rapidity by the use of absinthe.” The amount of absinthe consumed in London has during the last few years been enormously on the increase. See Liqueurs.

ABSINTHIN. C₁₆H₂₂O₅. The bitter principle of wormwood (Artemisia absinthium). A hard crystalline solid, having an intensely bitter taste; slightly soluble in water, very soluble in alcohol, less so in ether. Its physiological effects resemble those of extract of wormwood. Dose. ¹⁄₂ gr. to 2 gr., or more; in dyspepsia; as a stomachic, to promote the appetite, &c.; as a substitute for quinine in intermittents; and in worms.

ABSOLUTE. Syns. Absolutus, L.; Absolu, Fr.; Undebingt, G. In chemistry, pure, unmixed; as absolute alcohol, pure spirit of wine, i.e. free from water.

ABSORBED′ (-sorbd′). Syn. Chilled; Absorbé, Fr. In painting, a term among French connoisseurs, to represent that state of a picture in which the oil has sunk into the canvas or ground, leaving the colours ‘flat,’ and the touches indistinct. The remedy consists in rubbing the surface of the picture, previously well cleaned, with a soft sponge dipped in a little drying oil, and after some days varnishing it; when it should be kept in a warm room until perfectly dry.

ABSORB′ENT. Syn. Absorb′ens, L.; Absorbant, Fr.; Absorbirend, Ger. Imbibing; that imbibes or sucks up; variously applied in science and art. (See below.)

Absorbent Ground. In painting, a picture-ground prepared wholly or chiefly in distemper or water colour, in order that the redundant oil in the colours subsequently applied may be immediately ‘absorbed,’ by which expedition is permitted, and brilliancy imparted to them.

Absorbent Surfaces. In the arts, these are usually rendered non-absorbent, preliminary to their being bronzed, gilded, painted, or varnished, by giving them one, or more, coats of thin size, so as to destroy their porosity; care being taken to allow each coat to become thoroughly dry before the application of the next one; and also, finally, to remove any unabsorbed excess of size from the surface, by means of a sponge dipped in warm water. This applies to ALABASTER, PAPER, WOOD, PLASTER CASTS, &c.; and to WALLS and CEILINGS which are not exposed to the weather, and which there is not time to prepare with drying oil. See Bronzing, Maps, Varnishing, &c.

Absorption and consequent adherence in porous moulds, as those of plaster, are usually prevented by thoroughly saturating the pores of the mould with melted tallow, or a mixture of tallow and bees’ wax; or for delicate objects or the electrotype, with white wax. The ‘dry moulds’ are either heated before the application of these substances, or they are boiled in them; any portion that may finally remain unabsorbed, being carefully removed with cotton-wool or a soft rag. Another method is to wash the moulds over two or three times with drying oil, or to boil them in it; after which they must be exposed to the air for some days, to dry and harden. Before being used for plaster, composition, &c., the surface of these prepared moulds require to be slightly moistened with sweet oil.

Plaster moulds are generally prepared for sulphur, wax, and gutta percha casts, by simply placing them (upright) with the back immersed in a little water, contained in any shallow vessel, as a saucer or plate; and letting them remain there until moisture begins to appear on the surface. The materials to be cast, or moulded, should then be used at the lowest possible temperature, to prevent the formation of air-bubbles.

The adherence of wax or mixtures containing it, and of gutta percha, is best prevented by moistening the surface of the mould (whether of plaster, metal, or gutta percha), immediately before use, with soft soap reduced to the consistence of thin cream with water. See Casts, Moulds, Electrotype, &c.

ABSORB′ENTS. In anatomy and physiology, two distinct sets of small, delicate, transparent vessels, which imbibe or suck up fluid substances, and convey them to the blood. They are termed lacteals or lymphatics; the former take up the chyme from the alimentary canal, the latter pervade almost every part of the body in which they absorb lymph.

Absorbents. In botany and vegetable physiology, the origins of the different vessels constituting the vascular tissue, as they are found in the root, where they imbibe or suck up the nutritive fluids from the soil. See Plants and Vegetables.

Absorbents. In agriculture and chemistry, substances which possess the power of withdrawing moisture from the atmosphere; as soils, argillaceous earths, &c. Also (but less frequently) substances which neutralise acids; as chalk, lime, and magnesia. Absorbents differ from ‘deliquescent salts’; the latter attract moisture and dissolve in it; whilst the former merely suck it into their pores, as a sponge does water. See Absorption.

Absorbents. Syn. Absorben′tia, L. In medicine and pharmacy, substances which remove acidity from the stomach and bowels. Of these the principal are—magnesia, carbonate and bicarbonate of magnesia, prepared chalk, and the carbonates and bicarbonates of potash, soda, and ammonia. The first four are popularly called earthy absorbents; and the others, alkaline absorbents. See Antacids.

The following absorbent mixtures are taken from Dr Kirby’s valuable work, ‘Selected Remedies’:11

1. Infusion of rhubarb, 1¹⁄₂ oz.; compound spirit of ammonia, 1¹⁄₂ dr.; compound infusion of gentian to 6 oz. Two tablespoonfuls to be taken 3 times a day.

2. Bicarbonate of potash, 1¹⁄₂ dr.; syrup, 2 drs.; compound spirit ammonia, 1¹⁄₂ dr.; compound infusion of gentian to 6 oz. Two tablespoonfuls to be taken 3 times a day.

3. Bicarbonate of soda, 1¹⁄₂ dr.; spirits of chloroform, 1¹⁄₂ dr.; infusion of calumba to 6 oz. Two tablespoonfuls to be taken 3 times a day.

ABSORP′TION. [Eng., Fr.] Syn. Absorp′tio, L.; Einsaugung, Ger. The act or the power of absorbing, in various applications. (See below.)

Absorption. In agriculture, the power possessed by soils of absorbing moisture from the atmosphere. The more a soil is divided by labour and vegetation, the greater is its absorbent power, and, consequently, its fertility. Indeed, the latter chiefly depends on its capacity for imbibing moisture, and may be illustrated by reference to recent and disintegrated lava. (Leslie.) The finely divided state, most penetrable by the delicate fibres of plants, appears to derive its superior power of acting on atmospheric vapour from the augmentation of its surface and the multiplication of its points of contact. (Ure.) This method of increasing the fertility of a soil is well known to scientific farmers, and seldom neglected by them. (Loudon.) That soil must be regarded as the most fertile which possesses this power in the greatest degree. Garden-mould has the highest absorbent power of any mineral substance. (Leslie.)

Process of ascertaining the ABSORBENT POWER OF SOILS, and other substances. Thoroughly dry the article by the suitable application of a heat not exceeding 212° Fahr., continued for several hours, and transfer it, while still warm, into a clean dry phial furnished with a perfectly tight ground-glass stopper. When cold, quickly and cautiously introduce it, along with a delicate hygrometer, into a large wide-mouthed glass bottle, the atmosphere of which has been previously rendered as damp as possible, by suspending a piece of moistened rag or filtering paper in it. It must now be kept closed for some hours, when the hygrometer will indicate the degree of dryness of the enclosed air, and, consequently, the absorbent power of the substance examined.

Obs. Experiments of this nature are only relatively correct, and must be performed under exactly similar circumstances, to furnish reliable comparative results. The whole process, in each case, must be as similar as careful manipulation can possibly make them. With this reserve, they will be found invaluable to the agriculturist.

Absorption. In chemistry the passage of gases and vapours into liquid and solid substances. Thus, water absorbs the oxygen of the air, lime absorbs water, charcoal absorbs ammoniacal and other gases.

Absorption. In physiology (animal and vegetable), the function of sucking, or taking up, of appropriate substances, by the ‘absorbent vessels.’ It is one of the chief vital functions, the primary object of which is to convey to the circulatory organs the proper supply of the materials necessary for the support and growth of the body; and subsequently, to remove and convey to these organs its effete and useless portions, in order to their ultimate elimination from the system.

Absorption. In surgery, the natural process by which tumours and their contents, morbid growths, and, sometimes, even healthy glands, &c., are gradually taken up and disappear, by the action of the ‘absorbents.’

ABSTERG′ENTS. Syn. Abstergen′tia, L. In medicine and pharmacy, substances which cleanse or clear away foulness from the surface of the body or sores; as soap, lotions, &c. See Detergent, which has a nearly similar meaning, and is in more general use.

AC′ARI (-rī). [L.; prim. Gr.] Syn. Acar′idans; Acar′ides (dēz); Acarid′iæ. (-e-ē). In entomology, a division of arachnidans, including the mite and tick. All the species are either microscopic or extremely minute, and possess such tenacity of life as to resist for some time the action of boiling water, and to live with comparative impunity in alcohol. Leuwenhoek had one that lived eleven weeks glued on its back to the point of a needle, without food. The following are well known—ACARUS AUTUMNA′LIS, the harvest-bug or wheal-worm; A. DOMES′TICUS, the domestic tick; A. DYSENTE′RIÆ, the dysentery-tick; A. FARI′NÆ, the meal mite (fig. a); A. RI′′CINUS (rĭc-), the dog-tick; A. SAC′CHARI, the sugar-mite (fig. b); A. SI′′RO, the cheese-mite (fig. c); A. SCABIE′I, the itch-insect (fig. d).

The irritation of the skin, caused by these vermin, may be relieved by a lotion of equal parts of sal volatile and water; and they may be destroyed by tobacco water, or a lotion or ointment of stavesacre. See Itch, Mange, Parasites, Pediculi, Scab, &c.

Acarus Farinæ, or meal-mite (fig. a). This insect is found only in damaged flour, and is more frequently met with in the flour of the leguminosæ (beans, peas) than in that of the gramineæ (wheat, rye, oat).

Now and then a single acarus may occasionally be found in good flour, but even one should be regarded with suspicion, and the12 flour should afterwards be frequently examined to see if they are increasing.

Most of the brown sugars of commerce are infested by this pest, which is of a size sufficiently large to be visible to the naked eye. The following method of proceeding will lead to its detection:

Dissolve 2 or 3 teaspoonfuls of sugar in a large wineglass of tepid water, and let the solution remain for an hour or so, at the expiration of which time the acari may be found, some on the surface of the liquid, some attaching themselves to the sides of the glass, and some at the bottom, mixed up with the copious and dark sediment, made up of fragments of cane, woody fibre, grit, dirt, and starch granules, which usually subside on dissolving even a small quantity of sugar in hot water. When first hatched this acarus is hardly visible.

Acari of all sizes—that is, in all stages of growth—may be met with in most samples of sugar.

Dr Hassall, in seventy-two samples of sugar which he examined, found sixty-nine containing them.

Acarus Siro, the cheese-mite (fig. c). The dry and powdery parts of decayed cheese, which by careful watching may very frequently be seen in movement, consist almost wholly of this insect and their eggs in different stages of development. The cheese-mite can hardly be seen without the aid of the microscope. They are very tenacious of life, even when kept without food. Mr Blyth says that under these circumstances “it is no uncommon sight to see them killing and devouring each other; and that cheese is rapidly destroyed by them; they crumble it into minute pieces, and emit a liquid substance which causes the decayed parts to spread speedily.” They may be destroyed by being exposed to a strong heat, or by putting the cheese for a short time in whisky.

Acarus Scabiei, the itch-insect (fig. d). The parasitic character of the disease known as the itch was first demonstrated by Dr Bononio, who13 on turning out the contents of one of the little bladders that show themselves between the fingers of those affected with the complaint, and placing the fluid under the microscope, discovered a minute animal, very nimble in its movements, covered with short hairs, having a short head, a pair of strong mandibles or cutting-jaws, and eight legs, terminating in remarkable appendages, each provided with a sucker and setæ.

It has no eyes; but when disturbed it quickly draws in its head and feet, and then somewhat resembles the tortoise in appearance, its march being precisely the same. It usually lays sixteen eggs, which are carefully deposited in furrows under the skin, and ranged in pairs; these are hatched in about ten days.

“To find the itch-insect,” says Mr Jabez Hogg, “the operator must carefully examine the parts surrounding each pustule; he will then see a red line or spot communicating with it; this part, and not the pustule, must be probed with a fine-pointed instrument. The operator must not be disappointed by repeated failures.”

ACCIDENTS. Black eye. Bathe the eye frequently with a soft piece of linen rag dipped in a lotion composed of one part of tincture of arnica and seven parts of water.

Choking, or suffocation from substances sticking in the throat. Refer to Choking.

Precautions against Lightning. To take refuge under a tree during a thunderstorm accompanied by lightning is to expose oneself to a double danger—firstly, because by keeping the clothes dry these are prevented becoming the non-conductors they would be if damp; and secondly, because the tree, serving as a point of attraction for the lightning, conducts it to the ground, and in doing so frequently rends the trunks or branches, and kills any person or animal who happens to be close to, or in contact with, it at the time.

Never, therefore, if overtaken by a storm of thunder and lightning fly to the dangerous cover of a tree, pillar, hay-rick, wall, or hedge, but seek shelter in the nearest dwelling; or if this is not at hand, get to a part of the road or field where there is no object to attract the lightning, and there remain till the storm has expended itself. Also avoid particularly the proximity of iron gates, palisades, bronze statues, bell wires, iron railings, and such like. When in the house, do not sit or stand near the windows, doors, or walls, but place yourself in the middle of the room, unless there should be a lamp or chandelier hanging from the ceiling. Franklin recommends persons to keep away from the neighbourhood of fireplaces.

Treatment of persons struck by lightning. In case of any person being struck by lightning, immediately strip the body and throw bucketsful of cold water over it for ten or fifteen minutes; continued frictions and inhalations of the lungs must also be employed, and electricity should be tried if it be possible.

Accidents by Poison. The means to be adopted in cases where poison is taken, if the poison be known, are embodied in the antidotes, which will be found given in this volume under the respective poisons.

Under all circumstances, however, medical aid should be sought as expeditiously as possible, since many of the antidotes themselves being of a dangerous, if not poisonous, character, should only be administered under medical supervision. Pending the arrival of the doctor, no time should be lost in giving an emetic, consisting of a teaspoonful of flour of mustard in half a pint of warm water, supplemented by copious draughts of warm water, and tickling the throat with the finger if necessary.

Fish poisoning. It is a not unfrequent occurrence to find fish when eaten giving rise to a species of poisoning of a more or less violent form, such as a sense of weight at the stomach, accompanied with nausea, vertigo, headache, heat about the head and eyes, pains in the stomach, thirst, and often an eruption of the skin resembling nettle-rash. These symptoms may be sometimes due to the nature of the fish itself; sometimes to its being in a state unfit to be taken as food, as, for instance, when it is in a stale or decomposing condition; and occasionally to the peculiarity of constitution of those who partake of it, even if in a perfectly fresh condition. Whenever any of the symptoms above described follow from eating fish, an emetic of mustard and water (a teaspoonful of mustard in half a pint of water) should be administered. If subsequently a rash should appear, it would be well to take a dose of brisk purgative medicine, and, if necessary, a few doses of carbonate of soda 3 or 4 times during the day.

Poisonous Mushrooms. The same treatment should be followed as for fish. With some people the edible mushroom acts as a poison.

Sinks. See that these be securely trapped, and in the event of any unpleasant smell from them, pour down some disinfectant, such as chloride of lime, carbolic acid, or Condy’s fluid. The foul emanations from a sink ought to be regarded as of a most dangerous and pestilential nature.

Accidents to Children. Many, if not most, of the casualties to which children are exposed are given above, together with the best course to be pursued in the event of their being overtaken by any of them. There are, however, a few forms of disaster which seem more especially14 peculiar to children. Of these we may select—

Swallowing a piece of broken glass. In this case avoid giving purgatives, but give solid farinaceous food, so as to envelope the glass and enable it to pass through the bowels without causing injury by coming in contact with them.

Swallowing a coin. Give a dose or two of castor oil, and examine the stools until the coin is perceived.

A small coin sticking in the windpipe. Seize the child by the legs, letting his head hang downwards, then administer several brisk blows on the back with the palm of the hand, when very frequently the coin will be coughed out of the mouth and on to the floor. If this plan do not succeed, send immediately for medical aid.

ACCLI′MATE, or ACCLI′MATISE. In botany and zoology, to inure a plant or animal to a climate to which it is not indigenous. When so inured it is said to be ACCLIMATED. In medicine, to habituate the body to a foreign climate, so that it may not be peculiarly liable to its endemic diseases; or to become so habituated. Thus, a person who has resided several years at New Orleans without an attack of yellow fever, or having had an attack has satisfactorily recovered, is said to be ACCLI′MATISED.

ACCUMULA′TION. [Eng., Fr.] Syn. Accumula′tio, L. In medicine, a term applied when the effects of the first dose of any substance still continue when the second is administered (accumulation of action); or when several doses of insoluble substances remain inactive in the system until their energy is developed by chemical influence (accumulation of doses). See Medicines, Poisons, &c.

ACEPH′ALANS. Syn. Aceph′ala, Cuv. In malacology, a class of aquatic mollusca, having no apparent head, but a mouth between the folds of their mantle. Several of them, as the oyster, cockle, mussel, scallop, &c., are consumed for food.

ACERB′ITY. Syn. Acerb′itas, L.; Acerbité, Fr.; Herbigkeit, Ger. In chemistry, &c., sourness, with bitterness and astringency, or harshness. See Cider, Fruit, Wine, &c.

ACERBO’S ANTI-RHEUMATIC AND ANTI-CATARRH OIL. For various horse diseases. Gum euphorbium, 10 parts; absolute alcohol, 10 parts; olive oil, 80 parts. Digest in a warm-water bath for 24 hours, then boil until all the spirit has evaporated, and, when cold, strain through cotton. (Hager.)

ACES′CENT. Syns. Aces′cens, L.; Acescent, Aigrelet, Fr.; Säurlich, Ger. In chemistry, &c., growing sour; slightly tart or acid; having a tendency to sourness, or to run into the acetic fermentation, as wine, beer, malt-wort, &c. Hence, ACES′CENCE or ACES′CENCY (acescen′tia, L.; acescense, aigreur, Fr.; säurlichkeit, Ger.), the tendency to become slightly acid, or the quality of being so. See Acetification, Malt-liquors, Wine, Wort, &c.

ACETA′′RIOUS (-tāre′-e-ŭs). Used for salads (as plants); relating to salads (which see).

AC′ETATE (ăs′-). Syn. Ace′tas, L.; Acetate, Fr.; Essigsäure salze, Ger. In chemistry, a salt consisting of C₂H₃O₂ (sometimes called the acid-radical of the acetates) with hydrogen, a metal, or a compound basic radical; e.g.,

Hydrogen acetate (acetic acid)	HC₂H₃O₂
Potassium acetate	KC₂H₃O₂
Lead (plumbic) acetate	Pb(C₂H₃O₂)₂
Ammonium acetate	NH₄C₂H₃O₂

Salts of acetic acid (HC₂H₃O₂) with the alkaloids are likewise termed acetates; e.g.,

Prep. That of the commercial acetates, and of many others, is noticed under the respective metals. In general, they may all be formed by direct solution of the carbonate, hydrate or oxide of the metal whose acetate it is desired to form, in dilute acetic acid; or from a solution of an acetate and of another salt of the metal, by double decomposition. In either case, the resulting solution must be carefully evaporated by a gentle heat, and, where possible, crystallised.

Prop., &c. All the neutral acetates, except those of molybdenum and tungsten, are more or less soluble in water, several so much so as to be uncrystallizable; many dissolve in alcohol; they suffer decomposition at a dull red heat, and by distillation, at that temperature, yield acetone and water, or acetone and acetic acid, and leave a carbonaceous residuum; at a full red-heat, those of potassium, sodium, barium, strontium, calcium, and magnesium, are converted into carbonates, whilst the other metallic acetates leave behind the pure metal, or its oxide. The aqueous solutions of the alkaline acetates soon turn mouldy and suffer decomposition. No more of them should, therefore, be dissolved at once than is required for immediate use.

Char., tests, &c. The acetates are known—1. By evolving fumes of acetic acid, recognisable by its peculiar and characteristic odour, on the addition of strong sulphuric acid:—2. By evolving the vapour of acetic ether (known by its peculiar and agreeable odour) when heated with a mixture of about equal parts of concentrated sulphuric acid and alcohol.

AC′ETATED (ăs′-). In chemistry and pharmacy, combined or impregnated with acetic acid or vinegar.

ACE′TIC. Syn. Ace′ticus, L.; Acétique, Fr. Of or relating to vinegar; made with acetic acid, as perfumes, &c. (See below.)15

ACETIC ACID. HC₂H₃O₂. Syn. Pyrolig′neous acid (pure); Acid of vinegar; Acidum ace′ticum, L.; Acide acetique, Fr.; Acido acetico, It.; Essigsäure, Ger.; Azynzuur, Dut.; Eisel, Sax. When free from water it crystallises on cooling, and is distinguished as—Acetic hydrate, Hy′drated acetic acid, Monohy′drated a. a., Gla′cial a. a., Monohydrated a. a., Ace′tum glacia′le, Acidum ace′ticum G., L., &c. the sour principle of vinegar.

Var. Commercial acetic acid is found under the form of the pure acid of the chemist and pharmaceutist (glacial and dilute), and of vinegar, of which there are several varieties, which are noticed under their respective heads.

Sources. Fermented liquors; the vinegars of commerce; alcoholic liquors; wood, from which it is obtained, as pyroligneous acid, by distillation; the commercial acetates of soda, potassa, lime, lead, copper, &c. The pure acetic acid of the chemist and of commerce is almost wholly obtained from the acetates, either by the action of a strong acid, which seizes on the base, setting the acid free; or, by dry distillation, in which the high degree of heat employed separates the acetic acid from the base in the form of vapour. It is also obtained by the oxidation of alcohol.

Prep. The following are the principal processes at present adopted to obtain pure acetic acid:—

1. Commercial acetate of soda (i.e., the ‘pure acetate’ of the pyroligneous acid works), in crystals, is put into the body of a stout copper still, and a deep cavity being made in the centre of the mass, about 35% of sulphuric acid of a sp. gr. of not less than 1·84 is poured in; the walls of the cavity are then thrown in upon the acid, and the whole briskly agitated, for a very short time, with a large wooden spatula; the head of the still is next luted on, and the distillation conducted at a gentle heat, the receiver being changed as soon as the distillate begins to acquire a slight empyreumatic odour. The product, when the process is well managed, is an almost colourless acid of the sp. gr. of fully 1·05, containing about 40% of glacial acid, or between 34% and 35% of anhydrous acid. Any trace of colour or empyreuma is removed by agitation with some well-washed and recently ignited vegetable charcoal, or with a very small quantity of recently ignited purified animal charcoal, and subsequently passing it through a prepared calico bag-filter; or by allowing it to stand, for about a fortnight, in barrels containing some beech-wood chips; after which it is ready for sale, either as the ordinary acetic acid or pure pyroligneous acid of commerce, or (on dilution, &c.) as vinegar.

2. The acid of sp. gr. 1·05 (obtained as above) is distilled with fused chloride of calcium, the distillate being run into a refrigerator; the crystals that form are drained at a temperature below 40° or 45° Fahr., and after removal to a warmer temperature, where they liquefy, and agitation with a little peroxide of lead, are submitted to a second distillation, as before; and this is repeated until the whole of the acid crystallises at 51° Fahr. The product is the glacial acetic acid of commerce.

Obs. The above are the processes usually adopted, on the large scale, in this country.

3. (M. Mollerat’s process—without distillation.) Pure commercial acetate of soda, in coarse powder, is placed in a hard glazed stoneware or glass pan or receiver set in a cool situation, and 35% or 36% of concentrated sulphuric acid, of the sp. gr. 1·843, added, in such a manner that the acid may flow under the powder, and little heat be generated by the operation; the whole is then allowed to remain in contact (covered) for some hours, when crystalline grains of sulphate of soda are found covering the bottom and sides of the vessel, and hydrated acetic acid, partly liquid and partly in crystals, the upper portion. The temperature being now slightly raised to a point just sufficient to cause the liquefaction of the crystals of acetic acid (i.e., to from 62° to 65° Fahr.), the fluid is poured off, and a very small quantity of pure acetate of lime added to it gradually, until it ceases to yield any trace of free sulphuric acid on evaporation. After sufficient repose it is carefully decanted for use. An excellent commercial strong acetic acid is thus obtained, without distillation, owing to the insolubility of sulphate of soda in acetic acid; and from which glacial acid may be procured by refrigeration. If, however, the process be badly managed, or the proportions of the ingredients be not carefully observed, the product will be contaminated with either a little sulphuric acid or saline matter. It is also important to the success of this process that it be performed in a cool apartment, and in well-cooled vessels. Perfectly pure acetic acid may easily be obtained by rectification from this acid. The above plan of superseding a troublesome distillation is one of the greatest improvements yet introduced into the manufacture of acetic acid.

4. (Liebig’s process.) Pure acetate of soda, thoroughly dried and finely powdered, 3 parts, is placed in a capacious retort, and pure concentrated sulphuric acid, 9·7 parts, poured over it through the tubulature. One eighth of the acetic acid passes over by the heat developed by the reaction of the ingredients. The heat of a sand bath is next applied and continued until the contents of the retort become quite liquid. The distillate, carefully rectified, yields two parts of pure acid, containing only 20 per cent. of water. On exposing the latter portion which comes over in16 a closed vessel to a temperature below 40° Fahr., crystals of hydrated acetic acid are deposited. The weaker, or liquid portion, being poured off, the crystals are again melted and re-crystallised by cooling. The crystals of the last operation, separated from the liquid, and carefully drained in a cool and closed vessel, are perfectly pure hydrated acetic acid.

Obs. The above is an excellent process for obtaining a chemically pure acid. The excess of sulphuric acid left from the process may be recovered by distillation; or the whole residuum may be employed in a second distillation with fresh acetate.

Although a retort is recommended by Liebig for the distillation, and is usually adopted, on the small scale, for the purpose, a flask closed by a cork perforated by two tubes, as exhibited by the engr., will be found more convenient and safe; as the product is then less likely to be contaminated by the ‘spirting’ of the ingredients over the brim of the vessel. The heat of a diffused gas-flame may also be often advantageously substituted for a sand bath.

1. Acetate of potash (fused and powdered) is placed in a still, or other suitable vessel, and 50% of the strongest sulphuric acid (‘oil of vitriol’ of fully 1·84 sp. gr.) being added, the mixture is distilled to dryness, as before. The product is 50 to 51% of the weight of the acetate employed, with a sp. gr. of about 1·0735 to 1·074, containing about 66% of anhydrous acetic acid, or nearly 80% of ordinary glacial acid. By rectification from a little dried acetate of lead a perfectly pure acid of almost any strength may be obtained. The ingredients are nearly in equiv. proportions.

1. (Ure.) Take of dried acetate of lead, 4 parts; strongest oil of vitriol, 1 part. Distil slowly to dryness. Nearly equal to the last.

3. (Dollfuss’ Concentrated Acetic Acid.) Take of dried acetate of lead, 12 oz.; sulphuric acid, 6 oz.; distil 7 ounces.

1. (Christl.) Raw acetate or pyrolignate of lime (prepared by Völckel’s process), 100 parts, is mixed with hydrochloric acid (20° Baumé, or sp. gr. 1·1515), 120 parts; and after 12 hours, distilled in a copper vessel, with a gradually applied heat. The product is 100 parts or lbs. of acetic acid of 8° Baumé (sp. gr. 1·0556), containing about 47% of hydrated acid, only slightly coloured and empyreumatic, fit for various manufacturing purposes. The advantage of this process is the low price of hydrochloric acid, and the product not being contaminated with sulphuric or sulphurous acid.

Obs. It will be found that pyrolignate of lime generally contains 60% to 70% of neutral acetate; but should it contain either more or less, a proportionate quantity must be employed. When the proper proportions are used the distillate gives only a scarcely perceptible turbid cloud when tested with nitrate of silver. If the hydrochloric acid used has the sp. gr. 1·16, a less quantity being employed, the product will have the sp. gr. of 1·058 to 1·061, and will then contain from 48 to 51% of the monohydrate, or 41 or 42% of anhydrous acetic acid. The resin sometimes17 found floating on the mixed ingredients should be carefully removed, by skimming, before distillation.

As acid of the above strength is rarely required, and as the distillation is more easily conducted when the ingredients are less concentrated, a little water may be conveniently added either before or towards the end of the distillation. Hence the following proportions have been recommended:—

2. (Völckel.) Acetate of lime (as last), 100 parts; hydrochloric acid (sp. gr. 1·16), 90 to 95 parts; water, 25 parts; mix, and proceed as before. Prod. 96 to 98 parts of an excellent acid, well adapted to trading purposes, having a sp. gr. about 1·050, and containing nearly 40% of hydrated acetic acid. It has been correctly remarked, that the acetic acid produced with hydrochloric acid is always of better quality than that produced with sulphuric acid; being not only less coloured, but also entirely free from sulphurous acid. The distillation uniformly proceeds with ease and regularity, and the whole of the acetic acid passes over between 212° and 248° Fahr.; by which the danger of contamination with other products, resulting from a high degree of heat, is obviated.

3. An Acetic acid sufficiently strong and pure for many ordinary purposes may be obtained without distillation, by pouring strong sulphuric acid, 60 parts, diluted with water, 5 parts, on well-dried acetate of lime, 100 parts; digesting, with occasional agitation in a close vessel, decanting the clear liquid, and straining the remainder.

1. Acetate of lead (dried), 5 parts; and sulphate of iron (gently calcined), 2 parts; are separately powdered; and after thorough mixture, carefully distilled, by the heat of a sand bath, into a well-cooled receiver. An economical process for a strong acid, under certain circumstances; but one now seldom adopted.

2. (Bardollier’s Strong Acetous acid.) Dried acetate of lead, 10 oz.; calcined green vitriol, 12 oz.; as the last.

b. From the ACETATES OF COPPER:—By substituting acetate or diacetate of copper, in equiv. proportions, or better with excess of the sulphate. Seldom used.

a. From ACETATE OF COPPER:—Aromatic v.†; Spirit of verdigris†; Spiritus ven′eris†, L.; Esprit de venus, Fr.; Acidum ace′ticum, (Ph. L. 1787.) Process. Carefully dry crystallised verdigris (diacetate of copper) by a very gentle heat, and introduce it into a large stoneware retort (see engr.), the bottom of which has been previously coated with a mixture of clay and horse-dung, to render it more capable of standing the fire. Next place it in a suitable furnace, and connect it, by an adapter, with 3 or 4 double tubulated globes, the last of which must be furnished with a vertical tubulature, to which a double Welter’s safety-tube should be adapted; the other end being immersed in a basin half-filled with distilled vinegar or water, while the funnel portion communicates with the atmosphere. Then place each globe in a basin of water, kept cool by a stream constantly passing through it; and cover the upper portion with cloths kept continually wet with cold water. After 15 or 20 hours, fire may be applied, and must be so regulated that the drops follow each other with considerable rapidity from the end of the adapter, whilst the bubbles of air cause no inconvenience at the other end of the apparatus. If otherwise, the fire must be damped a little. The operation should be continued, and the fire gradually increased, until vapour ceases to come over, known by the globes gradually cooling, notwithstanding the heat of the furnace. The operation being concluded, the whole may be allowed to cool, and the acid collected preparatory to rectification. This may be effected in a similarly arranged apparatus, except that it must be wholly of glass; and the retort should not be much more than half-filled. The operation must now be very18 carefully conducted, and discontinued before barely the whole of the acid has distilled over; as the last portion is apt to injure the flavour and colour of the rest. The first portions which come over are very weak, and should be kept separate, until the sp. gr. reaches to about 1·372, when the receiver should be changed, and the product collected in separate portions, as noticed below.

Obs. Good diacetate of copper yields, by careful management, at a temperature of 400° to 560° Fahr., fully one half its weight of a greenish-coloured acid, of the sp. gr. of about 1·061, containing above 50% of hydrated acetic acid, or 43% of anhydrous acid. 20 lbs. of the ordinary acetate yields 9³⁄₄ lbs. of this rough acid, leaving a residuum of about 6¹⁄₂ lbs. of metallic copper mixed with a little charcoal, in the retort; the remainder (nearly ²⁄₁₀ths of the acid in the acetate) being decomposed by the heat, and lost. This 9³⁄₄ lbs. of crude acid yields by rectification, and dividing the products, ¹⁄₂ lb. of acid of the sp. gr. 1·023; 3 lbs. of the sp. gr. 1·042; and 6 lbs. of the sp. gr. 1·065; exclusive of a little acetone which comes over with it. In the first distillation, the strongest acid is found in the third receiver, and the weakest in the first. The acid obtained in this way is always accompanied with a little fragrant pyro-acetic spirit; which renders it preferable for aromatic vinegar and perfumery. It dissolves camphor, resins, and essential oils with facility. This is one of the oldest methods of obtaining glacial acetic acid, and the product is still preferred for some purposes. It is the RADICAL VINEGAR of the alchemists, and it is that which is preferred by the perfumers. Well-dried acetate of lead, or of iron, as well as several other acetates, may be substituted for acetate of copper in the above process; but are less economical and convenient. In all cases, great care must be taken to avoid over-firing, as thereby the quantity obtained is lessened, and the quality injured. The residuum of the distillation is pyrophoric and frequently inflames spontaneously, on exposure to the air. Due caution must be therefore observed regarding it.

IV. From Wood, by dry distillation. See Pyroligneous Acid. The preparation of the purified acid, by converting it into an acetate, and subsequent distillation with a strong acid, is noticed above.

V. From Alcohol. (Alcohol vinegar, German acetic acid.) In a bell-glass, or an oblong glass case, perforated shelves are arranged, a few inches apart, one above another, on which are placed a number of small flat dishes of porcelain, earthenware, or wood. These dishes are filled with spirit of wine or dilute alcohol; and over each is suspended a watch-glass or capsule containing a portion of platinum-black; the whole being arranged so that the platinum-black and the surface of the alcohol are not more than 1¹⁄₂ to 2 inches apart. Strips of porous paper are next so hung in the case, that their bottom edges are immersed in the spirit, to promote evaporation; and lastly, the apparatus, loosely covered, is set in a light place at a temperature of from 70° to 90° Fahr.—the sunshine, when convenient. In a short time the temperature of the platinum rises, and the formation of acetic acid begins; and the condensed vapour trickles down the sides of the glass and collects at the bottom of the case, whence it is removed once or twice a day. (See engr.) The product of a case of twelve cubic feet content, with 7 or 8 oz. of platinum-powder, is capable of producing daily, if well managed, nearly 1·31 lb. of hydrated acetic acid from 1 lb. of absolute alcohol; 25 lbs. of platinum-powder and 300 lbs. of alcohol will, in like manner, furnish a daily supply of nearly 350 lbs. of pure acid, and of other strengths in proportion. Theoretically, the product should be 130 parts of the hydrated acid for every 100 parts of alcohol consumed; but this is never quite obtained in practice, owing to a small portion of the alcohol mixing with the newly formed acid, and escaping decomposition; and from another small portion of both the alcohol, and of the newly formed aldehyd, being carried off by the air that permeates the apparatus. The platinum-powder does not waste, and the most inferior spirit may generally be employed.

Rationale. In this process, the alcohol (as in other cases of acetification) is first converted into aldehyd; and this, as rapidly as formed, absorbs oxygen and passes into hydrated acetic acid. The simultaneous formation of aldehyd during the oxygenation of19 that already formed, may be detected by its odour.

Obs. During the mutual action of the platinum-black and the vapour of alcohol, the temperature increases, and continues to do so until all the oxygen contained in the air enclosed in the case is consumed, when the acetification stops. On opening the case for a short time, to admit of a fresh supply of air, the operation recommences, thus showing its dependence on the oxygen of the atmosphere. For this transmutation, 100 grains of alcohol require 71 grains (equal to 200 cubic inches) of oxygen, or about 1000 cubic inches of atmospheric air. To render the process continuous and rapid, a fresh supply of air must, therefore, be constantly provided. This may be effected by either having a loosely covered opening at the top of the case, and several much smaller ones near its lower part; or (and preferably) by means of two small glass tubes passing through the lid or cover, one of which terminates just below the point of insertion, whilst the other divides into branches which reach to within a short distance from the bottom, as shown in the engraving. In this way a very slow current of fresh air will always be kept up in the apparatus.

In practice, we find, that by loosely spreading the platinum-black on pieces of platinum-gauze, and supporting these on small tripods or bars of glass or porcelain (or even wood), the watch-glasses and their troublesome suspension may be dispensed with; as also may be the strip of porous paper, provided a temperature of not less than 90° Fahr. be maintained in the case or acetifier, which may easily be done by the application of artificial heat in the absence of sunshine. On the large scale, a case of wood with a glass roof, or even a well-seasoned cask or vat may be employed, in which case the temperature of the apparatus must be kept up either by means of steam-pipes or flues, or by the supply of warm air. On the small scale, a hand bell-glass placed on a dish, with a single watch-glass or piece of platinum-gauze, and a single capsule containing alcohol, may be used, provided the bell-glass be supported on three very small wedges, to admit of a supply of air. A modification of this is sometimes employed, in which the alcohol is supplied, in drops, to the platinum-black, by means of a long, tubular funnel passing through the mouth of the bell-glass, and having its lower extremity drawn to a very fine point, as shown in the engr. To ensure success, the platinum-black should be either fresh-prepared, or recently washed and very gently heated, before placing it in the acetifier. Spongy platinum, though ordered by many chemical compilers, does not answer well for this process.

By the above elegant and economical process, perfectly pure acetic acid of considerable strength may be produced from even impure alcohol; but it is impossible in this way to obtain a concentrated acid without a subsequent operation, because the action of platinum-black on absolute alcohol, or even on strong alcohol, is so violent that the platinum soon begins to glow, and inflammation ensues. Unfortunately the revenue laws of this country, until lately, stood in the way of the adoption of this beautiful process, unless duty-paid alcohol or methylated spirit be employed; but there is no statute that prevents an individual employing pure spirit, of any strength, on the small scale, for private consumption. In Germany, and in the United States of America, vinegar is manufactured on this plan, and from the low price of crude alcohol there, it will no doubt prove ultimately to be the cheapest source of both pure acetic acid and culinary vinegars.

1. An excellent acetic acid, of considerable strength, may be made by soaking fresh-burnt and perfectly dry charcoal in common vinegar, and then subjecting it to distillation. The water comes over first, and on increasing the heat, the acid follows. Vinegar-bottoms and waste vinegar may be used.

2. By exposing vinegar, or dilute acetic acid, to the air in very cold weather, or to freezing mixtures, the water separates in the form of ice, and the strong acetic acid may be obtained by draining it into suitable glass vessels, observing to do so at a temperature sufficiently low to keep the water solid. Said to answer well in cold climates.

3. Acetic acid containing 20% of water may be deprived of a good deal of its superfluous water by standing over dry sulphate of soda. (Liebig.) It may then be used either with or without distillation.

4. Acetic acid, of ordinary strength, may be concentrated to any degree, by rectification once, or oftener, from dry acetate of potash or soda, rejecting the first and last portions. The same acetate may be used repeatedly. The temperature need not exceed 400°, and must not rise above 570° Fahr.

Acetic acid. (B. P.) Syn. Acidum aceticum. Water mixed with 33% of hydrated acetic acid. Prepared by distilling acetate of soda with sulphuric acid. Colourless sour liquid. Sp. gr. 1·044.

Prop. Pure hydrated acetic acid is a thin, colourless liquid above 62 Fahr.; at 50° to 55° it crystallises in large, brilliant, colourless, transparent needles and plates, and even at 60° if a crystal of the acid be dropped in; at 40° it is a solid crystalline mass. Sp. gr.—liquid,20 1·063 (Mollerat) to 1·0635 (Mohr);[3]—crystallised, 1·135 at 55° Fahr. (Ure). Odour, intensely pungent when concentrated, but grateful, fragrant, and refreshing, when diffused; taste, intensely sour and acrid, becoming agreeable and refreshing, on sufficient dilution with water; volatile; inflammable, burning with a white flame; vapour of boiling acid highly combustible; dissolves camphor, resins, gum resins, volatile oils, gelatin, gliadin, coagulated albumen, and fibrin (as muscle or the crassamentum of the blood); it coagulates casein, but not liquid albumen (as the serum of the blood and white of egg): miscible with alcohol, ether, and water in all proportions; boils at 248° Fahr.;[4] and is decomposed at a red heat. Its salts are called ACETATES (which see).

Char., Tests, &c.—1. Free acetic acid reddens litmus paper, like the other acids; and may be readily recognised by its odour and volatility:—2. Sesquichloride of iron being added, and the acid then nearly saturated with ammonia, the fluid acquires a deep dark-red colour.

Estim. See Acetimetry. Organic mixtures that cannot be thus tested, or from which the acid cannot be obtained by simple distillation, may be neutralised, if acid, with carbonate of lime, boiled for a few minutes, cooled, filtered, the lime precipitated with dilute sulphuric acid, and the whole submitted to distillation, when the acid contents of the distillate may be estimated as above.

Pur. By heat, it escapes (entirely) in vapour; nothing is precipitated on the addition of either hydrosulphuric acid, nitrate of silver, or chloride of barium. Sometimes it is contaminated with sulphurous acid, which may be recognised by putting a fluid drachm of the acid, mixed with an ounce of distilled water and half a drachm of pure hydrochloric acid, also a few pieces of granulated zinc, into a flask. While effervescence continues suspend a slip of white blotting-paper, moistened with solution of sub-acetate of lead, in the upper part of the flask above the liquid, for about five minutes. The paper should not be discoloured, and thus indicate the absence of sulphurous acid.

Adult. The acetic acid of the shops is chiefly adulterated with water. Sulphurous acid and lead are accidental contaminations; that of the latter often reaches 2%, making the acid poisonous.

Phys. eff., &c. In its concentrated state it is a corrosive and an acrid poison. Taken internally, it acts by dissolving the animal tissues, and by thus destroying the organisation causes death, like the other acids. In the dilute form it acts as a stimulant, rubefacient, alterative, refrigerant, and escharotic.

Uses. Acetic acid is much employed by the chemist and pharmaceutist, in the manufacture of various preparations, and in analysis; by the perfumer, in the composition of several of his most refreshing and agreeable scents; and in medicine, as an antiseptic, stimulant, rubefacient, alterative, refrigerant, and escharotic. Acetic acid (B. P.) applied by means of a piece of rag tied to the end of a small stick, is a nearly certain cure for ring-worm and scaldhead—one or two applications generally effecting a cure, and the severe smarting it causes is only of short duration; as a caustic, it removes warts and corns; a piece of lint or blotting-paper wetted with it and applied to the skin (evaporation being prevented), forms a useful extemporaneous blister. It was once employed as a disinfectant; but is now only used as a fumigation, to disguise the unpleasant smell of the sickroom and crowded assemblies. It is a popular refreshing scent in faintings, asphyxia, and nervous headache; and is a valuable rubefacient, astringent, and local stimulant. It is also used as a rubefacient and caustic in veterinary practice.

In the arts, the commercial acid (pure pyroligneous acid) is used by the engraver to etch his plates; as an antiseptic in pickling and preserving animal and vegetable substances used as food, and anatomical preparations; in dyeing and calico printing, and in the manufacture of medicated vinegars and other pharmaceutical preparations.

In the dilute state, its properties and applications are similar to those of ordinary vinegar, and are noticed under that head.

Poisoning from acetic acid is rare. When concentrated, it is capable, by its corrosive and solvent action, of perforating the coats of the stomach and digestive canal; and it colours the mucus of these organs by the chemical action it exerts upon the blood. Vinegar in an excessive quantity acts in a similar way, but in a slighter degree. The treatment and antidotes are similar to those directed in cases of poisoning by the other acids. See Poisons.

Gen. commentary. Acetic acid, on the large scale, is principally prepared from acetate of soda, which yields by a comparatively inexpensive, and not a difficult operation, an acid sufficiently strong and pure for commercial purposes, without the necessity of rectification. In this process shallow vessels of wood or of copper formed without rivets or solder (except silver solder) in those parts exposed to the action of the acid, are generally employed for the purpose of the distillation. A coil of drawn21 copper pipe, heated by steam having a pressure of 30 to 40 lbs. to the inch, traverses the bottom of the apparatus, to impart the necessary heat. The refrigerator consists of well-cooled earthenware, Berlin ware, or glass vessels; and the adopter pipe is also of the same materials. Another common form, which is even still more convenient, is a stout copper still, furnished with a cast-iron jacket to hold high-pressure steam, the usual refrigeratory being employed. In a few instances the space between the still and jacket is filled with sand, oil, tallow, or fusible metal; in which case the apparatus is set in brickwork, and heated by a naked fire. Stills of earthenware are also frequently employed; and even worms and condensers of silver, or silvered copper, are sometimes used, and with advantage. With a leaden worm the product is always contaminated with a little of that metal; the efforts of the manufacturer to the contrary, by the exclusion of air, and by rejecting the first and last portions of the distillate, only lessening and not preventing this evil. A lute (if any) composed of linseed meal and water, with or without a little powdered plaster of paris, may be employed; but flat bands and short tubes of well-seasoned vulcanised india rubber are infinitely more convenient and efficacious. The ingredients being placed in the still, and well but hastily stirred together with a wooden spatula, the head is luted on, and the distillation soon afterwards commenced. The chief care now should be to increase the heat gradually as the distillation proceeds; and when a steam-heat is not used, to carefully avoid over-firing, particularly towards the close of the operation. A little acetic ether is added by some manufacturers. In this way 4 lbs. of acid of the sp. gr. 1·050, is obtained for every 3 lbs. of acetate of soda employed. Should rectification be had recourse to, the addition of about 2 or 3% of bichromate of potash, peroxide of manganese, or red oxide of lead, will remove empyreuma, if present. The first of these substances is the most effective; the power of the others being in the order in which they are printed. In distilling the weaker acids and vinegars, it is found useful to add from 25 to 30% of chloride of sodium, which, by raising the boiling-point of the liquid, allows the acid the more freely to pass over (Stein); but this addition proves disadvantageous when any sulphuric acid is present, in which case sulphate of soda may be employed instead. If this addition be not made, the whole of the acid cannot be obtained without distillation to dryness, and the generation of empyreuma.

On the small scale, glass retorts are usually directed to be used, but glass alembics or flasks are more convenient and safe, as already noticed. In the preparation of the pure acid, care should be taken that the acetate of soda does not contain common salt, as the carbonate of soda prepared by calcination, and frequently used to form the acetate, is generally contaminated with it, and yields up its hydrochloric acid or chlorine during the process of distillation, thus vitiating the product. In all the methods given the product becomes more concentrated in proportion to the dryness of the acetate and the strength of the oil of vitriol or muriatic acid employed. By using the one dry, and the other concentrated, glacial acid may always be obtained by collecting separately the last two fifths that come over, and submitting this to refrigeration.

According to Melsens, pure GLACIAL ACETIC ACID is most advantageously obtained by distilling pure and dry acetate of potash with an excess of strong and moderately pure acetic acid, rejecting that which first passes over.

Acetate of soda may be safely dried at a temperature of 400° to 450°, provided care be taken to avoid ignition from contact with sparks. A less heat is, however, quite sufficient to drive off the whole of its water of crystallisation. It is known to be dry by its assuming the appearance of a smooth oily liquid whilst hot. If, whilst heated, it emits fumes, it is suffering decomposition. The same applies to the other commercial acetates. Crystallised acetate of soda loses about ²⁄₅ths of its weight by thorough drying.

When acetate of soda and sulphuric acid are the ingredients employed in the production of acetic acid, sulphate of soda is formed, which, in the large way, the chemist returns to the manufacturer of acetate of soda (i. e. to the pyroligneous acid maker), who employs it in the decomposition of fresh acetate or pyrolignite of lime. In this way the same soda-salt is employed over and over again, acting merely as the vehicle for the separation of the crude acetic acid in the solid form, and its easy and cheap transportation from one point to another. This ingenious method of mutual assistance resulting from the application of chemical science to provide for the wants of everyday life, offers some explanation of the extraordinarily low price at which acetic acid may now be purchased.

The acetic acid of commerce (pure pyroligneous acid) is almost wholly obtained from the acetates of soda and lime. The principal supply of crude acetate (pyrolignite) of soda is from America, Norway, and Sweden; but much is also obtained from our home manufactories. See Acetification, Acetimetry, Fermentation, Pyroligneous Acid, Sodium, (Acetate of), Vinegar, &c.

More recently, acetic acid has been obtained by decomposing with hydrochloric acid the double salt of chloride of calcium and acetate of lime, mentioned by Fritzsche (‘Ann. de Poggend,’ xxviii, 123). For this purpose, solutions of acetate of lime and chloride of calcium are mixed and evaporated, the combined salts readily crystallising in large needles. These are freed from the mother-liquor and distilled with common muriatic acid.22

The acid furnished by this method requires redistillation, and is, moreover, contaminated with some of the fatty products always present in the crude pyrolignite.

Aromat′ic Acetic Acid. Syn. Aromatic vinegar; A. spirit of v.; Acidum Ace′ticum aromat′icum, L.—Prep. 1. (Ph. E. 1839.) Dried rosemary and origanum, of each 1 oz.; lavender flowers, ¹⁄₂ oz.; bruised cloves, ¹⁄₂ dr.; acetic acid (sp. gr. 1·068), 1¹⁄₂ pint; macerate for 7 days, express, and filter. A fragrant and refreshing perfume. Omitted in Ph. E. 1841 and P. B. 1867.

2. (Ph. E. 1817.) As the last, but using distilled vinegar instead of the strong acid of the Pharmacopœia. Inferior.

3. (P. Cod. 1839) Camphor, 2 oz.; oil of lavender, 10 gr.; oil of cinnamon, 20 gr.; oil of cloves, 30 gr.; concentrated acetic acid, 1 pint. Very fragrant and refreshing.

4. (Ph. Bor. 1847; Cod. Med. Hamb. 1845.) Oil of cloves, 1 dr.; oils of lavender and citron, of each 2 scrup.; oils of bergamot and thyme, of each 1 scrup.; oil of cinnamon, 10 drops; strongest acetic acid, 1 oz.; mix. Limpid; yellow-brown; highly fragrant and refreshing. See Acetic Acid (Camphorated), and Vinegar (Aromatic).

Beaufoy’s Acetic Acid. A superior commercial acetic acid (i. e. purified pyroligneous acid), having a sp. gr. of about 1·044; or containing about 28% of real acetic acid, or 32 to 33% of the hydrated acid. Same strength, &c., as Acetic Acid P. B.

Cam′phorated Acetic Acid. Syn. Camphorated vinegar; Acidum ace′ticum camphora′tum, L.—Prep. 1. (Ph. E. 1841.) Camphor, ¹⁄₂ oz.; pulverise it by means of a few drops of spirit of wine, and then dissolve it in acetic acid (Ph. E.), 6¹⁄₂ fl. oz.

2. (Ph. D. 1850.) Camphor, 1 oz.; rectified spirit, 1 fl. dr.; pulverise, and dissolve in strong acetic acid (acid. acet. fort. Ph. D.), 10 fl. oz.

Obs. This preparation is intended as a substitute for the aromatic acetic acid of the shops and previous pharmacopœias. It is also useful as an embrocation, in rheumatism and neuralgia; as an extemporaneous vesicant and counter-irritant; and as a fumigation in fevers, &c.

Dilute′ Acetic Acid. Syn. Acidum aceticum dilu′tum, L. Acetic acid, 1 pint; distilled water, 7 pints; mix, Sp. gr. 1·006. One fluid ounce corresponds to 16 grains of anhydrous acid (3·63 per cent.).

Glacial Acetic Acid. Syn. Acidum aceticum glaciale. Acetate of soda, 20 oz., is liquefied by a gentle heat, stirred till it becomes pulverulent, and then further heated until it fuses; it is at once removed from the fire, and, when cool, the mass is broken up, placed in a 3-pint stoppered retort connected with a Liebig’s condenser, and then treated with sulphuric acid, 8 fl. oz. When the distillation slackens heat is to be applied, and the process continued until 6 fl. oz. of acetic acid have passed over. If a little of the product strikes a blue colour when mixed with a solution of iodate of potassium containing mucilage of starch, the whole product must be agitated with perfectly dry black oxide of manganese, ¹⁄₄ oz., and redistilled. Sp. gr. 1·065; contains 85% of anhydrous acid.

ACETIDUX, Dr DELFER’S. Made by Döllinger, of Berlin. For the radical and painless removal of warts, corns, hard skin, &c. A solution of 5 grms. of chromic acid in 15 grms. of water. (Schädler.)

ACETIFICATION. Syn. Acetifacio, L.; Acetification, Fr.; Essigmachen, Einsaüern, Ger. In chemistry, the act or process of converting into vinegar; also the state of undergoing such conversion.

Acetic acid is produced either by the partial dehydrogenation and subsequent oxidation of bodies containing its elements, or by their destructive distillation. The first is effected—by their exposure, in a finely divided state, to the action of air or atmospheric oxygen, as in the quick process of making vinegar; or—by submitting them, in combination with ferments, to contact with a free supply of atmospheric air, as in the old field process of making vinegar; or—by exposure to the direct action of chemical or mechanical oxidizing agents, as condensed air (platinum-black process), chromic and nitric acid, &c. In general, it is alcohol more or less dilute, particularly as it exists in fermented liquors, which is thus converted into acetic acid. In the second process (destructive distillation), wood is the substance usually employed, and heat is the agent which develops the acid.

The conversion of alcohol into acetic acid is not immediate and direct. The atmospheric oxygen first oxidises two atoms of its hydrogen, aldehyd and water being formed; and this aldehyd uniting with one atom of oxygen produces one molecule of ACETIC ACID. The changes are represented in the following equations:—

After the first formation of aldehyd, the two processes, unless artificially checked, go on simultaneously, as long as any undecomposed alcohol is present.

The conversion of alcohol into acetic acid, although greatly accelerated by the presence of nitrogenised organic matter (according to23 Mulder, of a fungus—the Mycoderma Vini or Vinegar Plant), is rather a case of eremacausis (slow combustion) than of fermentation. Acetification effects combination, as shown by the foregoing equations, whereas fermentation resolves complex bodies into simpler ones, e.g. sugar into alcohol and carbonic anhydride. Moreover, the presence of ferments is not essential to the change, since pure alcohol becomes acetified when exposed to the oxidising agents already named.

Another remarkable distinction between acetification and fermentation is, that the former requires the continued presence of atmospheric oxygen; whilst the vinous fermentation after being once established, proceeds perfectly without it.

During the oxidation of the alcohol of vegetable solutions, some of the other organic matters present also suffer change. A white gelatinous mass (mother of vinegar)[5] is commonly deposited; but this is a secondary result of the process, and not, as formerly supposed, one essential to it. In ordinary cases acetification occurs only at or near the surface of the liquid; which accounts for the length of time required for the operation under the old process of ‘fielding,’ and the shorter time in which it is accomplished by the improved process of Mr Ham. It proceeds favorably at temperatures ranging from 60° to 90° Fahr.; and most rapidly at 95° Fahr. (Liebig). In the ‘quick process’ of making vinegar a temperature of 90° to 92° is generally aimed at; but it often rises to 100°, or even to 105°, Fahr. As the temperature falls acetification proceeds more slowly, and at 46 to 50° Fahr. it ceases altogether (Liebig).

Aldehyd (see above) is an exceedingly volatile substance, and easily dissipated by a slight heat. It is, therefore, of the highest importance to duly regulate the temperature, as well as the supply of air, during acetification. In the ‘quick process’ of making vinegar the loss from this cause is always considerable, and often very great. This loss may be diminished by passing the heated air, as it escapes from the acetifier, through a porcelain or silvered copper worm or refrigerator, set in a chamber containing water of a temperature not higher than 40° to 45° Fahr.; the connection being made at the lower end of the worm, whilst the upper end is open to the air. On the small scale, as in the platinum-black process, the loss may be almost entirely prevented by causing the upper air tube to pass through a vessel containing ice or a freezing mixture; or by uniting it with the lower end of a Liebig’s condenser.

In liquors undergoing the vinous fermentation, a portion of the newly formed alcohol is invariably acetified whenever the temperature rises above 51° Fahr.; and at a higher temperature, this proceeds with a rapidity often highly injurious to the quality of the liquor. In this way there is frequently a useless loss of the alcohol, which is rendered more apparent by the incipient, and sometimes the actual, souring of the liquor.

ACETIM′ETRY. Syn. Acetom′etry; Acétométrie, Fr.; Acetime′tria, &c., L. The art or process of determining the quantity of pure acetic acid in vinegar, or in any other liquid. The plans generally adopted for this purpose are—

I. From the saturating power of the acid, as in the common methods of acidimetry:—

1. The molecular weight of commercially pure bicarbonate of potash, in crystals, being 100, whilst that of absolute acetic acid is 60, it is evident that every ten grains of the bicarbonate will exactly equal 6 grains of the acid. To apply this practically, we have only to exactly neutralise 100 gr. of the vinegar or solution under examination with the bicarbonate, observing the usual precautions; then, as 10 is to 6, so is the number of grains used, to the per-centage strength required. In this, as in other like cases, it is convenient to form a test-solution with the bicarbonate, by dissolving it in sufficient water to fill the 100 divisions of any simple form of ‘acidimeter,’ as a, b, or c; when the quantity of the solution, and, consequently, of the salt used, may be read off at once from the graduated portion of the tube. Still greater accuracy may be obtained by dissolving the bicarbonate in exactly 1000 gr. of distilled water contained in a ‘Schuster’s alkalimeter,’ previously very carefully weighed; in which case each grain of the test-solution will indicate ¹⁄₁₀th of a grain, or 0·1% of absolute acetic acid, whilst every 10 grains will be equal to 1 grain, or 1%.

The test-solution may also be prepared from bicarbonate of soda, or from the carbonates of soda or potash, care being taken that the quantity of the salt dissolved be in proportion to its molecular weight.

2. (Brande.) A small piece of white marble, clean and dry, is weighed, and then suspended by a silk thread in a weighed sample (say 100 or 1000 grs.) of the vinegar or acid under examination; the action being promoted by occasionally stirring the liquid with a glass rod, until the whole of the acid is saturated, as shown by no further action on the marble being observable on close inspection. The marble is then withdrawn, washed in distilled water, dried and weighed. The loss in weight24 which it has sustained will be nearly equal to the acetic acid present, or strictly, as 50 (marble) to 60 (absolute acetic acid). The only precautions required are, to avoid striking the piece of marble with the rod whilst stirring the solution, or causing loss of substance in it after its withdrawal; and to allow ample time for the action of the acid on it. If the sample consists of strong acid, it should be diluted with twice or thrice its weight of water before suspending the marble in it.

3. (Ure.) 100 grains of the sample under examination is slightly reddened with tincture of litmus, and ammonia of the sp. gr. 0·992 is added drop by drop (from an acetimeter holding 1000 water-gr. measure, divided into 100 divisions) until precise neutralisation is effected, indicated by the blue colour of the litmus being restored. The number of the divisions of the acetimeter used, multiplied by 60, and the first two right-hand figures of the product cut off as decimals, gives a number which represents the exact quantity of absolute acetic acid in the sample. In practice, it is found more convenient to keep the test-ammonia ready tinged with litmus.

The mode of estimating the per-centage of acetic acid in beers, when finding their original gravities, is a slight modification of the above. A test-solution of ammonia is prepared of such a strength that a given bulk of it will exactly neutralise one per cent. of absolute acetic acid in an equal bulk of beer, so that, if 100 fluid grains of the solution are sufficient to neutralise the acid in 1000 fluid grains of beer, such beer contains one tenth per cent. of acid. A solution of ammonia, diluted with distilled water until it has the sp. gr. ·9986 at 60°, is of the exact strength required.

An acetimeter holding 1000 grains, and graduated downwards to 100 equal divisions, is filled to 0 of the scale with the test-ammonia, which is then added, drop by drop, to 1000 measured grains of the beer, until neutralisation takes place. Every division of the acetimeter (corresponding to ten fluid grains), so emptied, indicates ·01 per cent. of acetic acid in the beer. The progress of the neutralisation is tested from time to time with a slip of reddened litmus paper, which should be suffered to become faintly blue before ceasing to add the ammonia. By this method the exact per-centage of absolute acetic acid in any sample may be accurately determined. The only precaution necessary is to be certain that the ‘test-ammonia’ has the required sp. gr. (·9986). Test-solutions may also be prepared with pure potash or pure soda.

II. From the specific gravity of the liquid after it has been neutralised with hydrate of lime:—

Common hydrate of lime (freshly slaked lime), in powder, is added gradually to the sample under examination, until it is saturated, when the sp. gr. of the resulting clear solution of acetate of lime is taken by Taylor’s ACETIMETER. This instrument is so adjusted and graduated as to float at the mark on the stem called ‘proof,’ in a solution containing 5% of absolute acetic acid (No. 24 vinegar). For vinegars stronger than proof small weights are provided, each of which indicates an additional 5 per cent. To ascertain the per-centage of real acid, 5% must therefore be added to the acetimeter number. Thus, without being loaded, the instrument, floating at the ‘proof mark,’ indicates a vinegar of 5%; with one weight, a vinegar of 10%; with two weights, 15%, and so on. According to this system of notation, each 5% is called a ‘vinegar.’ An acid of 10% is said to contain two vinegars; one of 15%, three vinegars, &c. It is also common to speak of the degrees of the acetimeter as proof or over-proof. Thus, No. 24 vinegar is said to be proof; one of 5 acetimeter degrees, 5 over-proof; one of 10 degrees, 10 over-proof, &c. For malt and wine vinegars, which contain gluten and mucilage, this method is not strictly accurate, as a portion of these substances escapes precipitation by the lime, and consequently alters the specific gravity. A small weight marked ‘M’ is generally supplied with the acetimeters for trying such vinegars.

The sp. gr. of the sample (carefully determined by any of the usual methods) is sought in one of the following Tables, when the corresponding per-centage content of acetic acid is at once seen.

This method furnishes reliable results only with pure, or nearly pure solutions which do not contain much above 50% of glacial acid, or which have a sp. gr. not higher than 1·062. It is also more to be depended on for weak solutions than strong ones. By carefully diluting a strong acid with an equal weight, or twice or thrice its weight of water, and allowing the mixture to again acquire its normal temperature, the sp. gr. may be taken as a guide in all cases in which great accuracy is not required. When such dilution is made it only becomes necessary to multiply the indication furnished in the Tables by 2, 3, or 4, as the case may be. As, however, authorities are not agreed as to the precise sp. gr. of the monohydrate or glacial acid, and of its solutions, extreme accuracy must not be expected by this method.

sp. gr.			per cent.
1·0085	contains of anhydrous	or real acetic acid	5
1·0170	”	”	10
1·0257	”	”	15
1·0320	”	”	20
1·0470	”	”	30
1·0580	”	”	40

Absolute Acetic Acid, per cent.	Sp. Gr.	Absolute Acetic Acid, per cent.	Sp. Gr.	Absolute Acetic Acid, per cent.	Sp. Gr.	Absolute Acetic Acid, per cent.	Sp. Gr.
Pure acid or
100	1·0630	74	1·0732	48	1·0582	22	1·0311
99	1·0648	73	1·0728	47	1·0568	21	1·0292
98	1·0663	72	1·0721	46	1·0557	20	1·0275
97	1·0677	71	1·0718	45	1·0553	19	1·0264
96	1·0685	70	1·0713	44	1·0544	18	1·0253
95	1·0696	69	1·0711	43	1·0535	17	1·0241
94	1·0704	68	1·0708	42	1·0525	16	1·0229
93	1·0708	67	1·0702	41	1·0518	15	1·0218
92	1·0715	66	1·0701	40	1·0513	14	1·0200
91	1·0721	65	1·0693	39	1·0502	13	1·0173
90	1·0726	64	1·0692	38	1·0492	12	1·0172
89	1·0729	63	1·0685	37	1·0482	11	1·0161
88	1·0730	62	1·0679	36	1·0473	10	1·0150
87	1·0731	61	1·0675	35	1·0460	09	1·0131
86	1·0732	60	1·0672	34	1·0449	08	1·0121
85	1·0733	59	1·0665	33	1·0439	07	1·0102
84	1·0734	58	1·0662	32	1·0425	06	1·0085
83	1·07343	57	1·0653	31	1·0413	05	1·0071
82	1·0735	56	1·0645	30	1·0402	04	1·0057
81	1·0738	55	1·0641	29	1·0392	03	1·0042
80	1·0743	54	1·0632	28	1·0380	02	1·0025
79	1·0742	53	1·0628	27	1·0364	01	1·0012
78	1·0740	52	1·0616	26	1·0352	00	1·0000
77	1·0739	51	1·0610	25	1·0341	or Pure water.
76	1·0736	50	1·0602	24	1·0330
75	1·0731	49	1·0593	23	1·0320

Concluding remarks. Before applying the above processes, account should be taken of any mineral acid which may be present in the sample, such being not unfrequently added to vinegar to impart artificial strength; and in those depending on the sp. gr., gum, gluten, &c., must also be allowed for. The methods depending on the saturating power of the acid will be found appropriate to acetic acid of all strengths, when unadulterated with the mineral acid. The method based on the sp. gr. is also very convenient, and is sufficiently accurate for distilled vinegars and for pure acids of moderate strength.

It is found that the decimal fraction of the sp. gr. of pure or nearly pure vinegar is doubled by its conversion into acetate of lime. Thus, 1·0085 in vinegar becomes 1·0170 when converted into a solution of acetate of lime. In malt vinegar, however, 0·005 may be deducted from the sp. gr. for mucilage and gluten. The quantity of foreign matter present in vinegar may therefore be approximatively ascertained, by deducting the decimal of the sp. gr. of the solution of acetate of lime from double that of the decimal part of the sp. gr. of the vinegar. Thus:—the sp. gr. of a sample of vinegar being 1·014, and after saturation with hydrate of calcium 1·023, the sp. gr. of the pure vinegar would be 1·009, and that due to foreign matter ·005. For—

·028 - ·023 = ·005

1·014 - ·005 = 1·009

The reason why proof-vinegar is called, in commerce, No. 24, is that 1 fl. oz. of it requires exactly 24 gr. of pure anhydrous carbonate of soda to neutralise it. Weaker vinegars are represented in the same ‘notation’ by the Nos. 22, 20, 18, &c., according to their respective strengths estimated by their saturating power.

ACETINE. An essence for the removal of corns. Concentrated vinegar (1·04 sp. gr.) slightly tinged with fuchsine, 15 grms. (Hager.)

ACETINE, HOCHSTETTER’S. Prepared by J. C. F. Witte, Berlin. A remedy for corns, warts, and hard skin. Diluted vinegar, coloured with blue carmine, 16 grms. (Schälder.)

ACETOLATS. [Fr.] Syn. Esprits acétiques. In French pharmacy, medicated vinegars obtained by distillation.

ACETOLES. [Fr.] In French pharmacy, medicated vinegars obtained by maceration.

ACETYL. Syn. Acetyle. A name originally given to a hypothetical body, having the formula C₂H₃, and regarded by Berzelius as the radical of 26the acetates and their congeners. The acetyl of Gerhardt (C₂H₃O) is, however, according to that chemist, the true radical of the acetates. Williamson, in order to remove the confusion of terms occasioned by the application of the same name to compounds of different composition, proposed the title of othyl for the radical C₂H₃O.

ACEIILE′INE (-kĭl-). A peculiar bitter principle obtained from achillé a millefolium (Linn.), or yarrow.

ACHROMAT′IC (ăk-ro-). Syn. Achromatique, Fr. In optics, devoid of colour; bodies that transmit light without decomposition, and consequently, without the formation of coloured rings or fringes; applied to compound lenses, prisms, &c., and to instruments fitted with them.

ACRO′MATISM. Syn. Achromatisme, Fr. In optics, the state of being achromatic; the absence of coloured fringes in the images of objects seen through a lens or prism.

Light is not homogeneous, but decomposable by refraction, absorption, or reflection, into coloured rays of unequal refrangibility. A ray of white light, in passing through a glass prism, is entirely separated into the coloured rays forming the ‘prismatic spectrum,’ and when it passes through a lens, an analogous resolution into coloured rays still occurs, though not so readily observed, and that to an extent often incompatible with distinct vision. Now, if a convex lens be regarded as a number of prisms united by their bases round a common centre, and a concave lens, as a similar number of prisms with their apices in contact, the action of lenticular and prismatic glasses on light will be reduced to a common principle. A beam of light thrown on a simple converging lens not only suffers refraction at the spherical surface (SPHERICAL ABERRATION), but the different coloured rays of which it is composed, from the causes mentioned, being unequally bent or refracted, diverge from their original course (CHROMATIC ABERRATION), forming as many foci on the axis of the lens as there are colours, and fall separately, instead of together, on the eye or object which receives them. Hence arise the coloured fringes or halos that surround objects viewed through ordinary glasses, and which form the great impediments to the construction of perfect lenses. This effect, like the refractive power and focal distance, varies in degree in different diaphanous substances.

The correction of the chromatic aberration of lenses is commonly effected by combining two, or more, made of materials possessing different ‘dispersive’ powers. Thus, the spectrum formed by flint glass is longer than that formed by crown glass, for the same deviation. When the two are combined, so as to form a compound lens, the one tends to correct the ‘dispersion’ of the other. On this principle ACHROMATIC GLASSES are generally formed in this country. A convex lens of crown glass is combined with a weaker concave lens of flint glass, the latter counteracting the dispersion of the former, without materially interfering with its refractive power. The resulting combination is not absolutely achromatic, but is sufficiently so for all ordinary purposes. According to Dr Blair, a compound lens perfectly achromatic for the intermediate, as well as for the extreme rays, may be made by confining certain fluids, as hydrochloric acid, between two lenses of crown glass. In order to produce nearly perfect achromatism in the object-glasses of telescopes, microscopes, cameras, &c., a concave lens of flint glass is commonly placed between two convex lenses of crown or plate glass, the adjacent surfaces being cemented with the purest Canada balsam, to prevent the loss of light by reflection from so many surfaces.

Obs. The production of perfect achromatism in lenses is a subject not less fraught with difficulty than with practical importance to the astronomer, the mariner, the microscopist, and the photographer; and it has hence engaged the attention of the leading mathematicians and artists of Europe up to the present time. All the larger object-glasses lately manufactured are said to consist of only two lenses; the resulting achromatism proving sufficiently exact for all useful purposes. Those of recent production have come chiefly from the workshops of Dollond, of London, and the opticians of Bavaria and Switzerland. The achromatism of prisms depends upon the same principles, and it is effected in the same way as that of lenses.

ACIC′ULAR. Needle-shaped; slender or sharp pointed; spicular; in botany, applied to leaves, and in chemistry, to crystals. The last are also sometimes termed ACIC′ULÆ.

ACID, Syn. Acidum, L.; Acide, Fr.; Acido, Ital.; Säure, G. In familiar language, any substance possessing a sour taste. In chemistry, substances are said to be acid, or to have an acid reaction, when they are capable of turning blue litmus red. In chemistry, also, the term acid is applied to a very large class of compounds containing hydrogen (hydrogen salts), and in which one or more atoms of that element may be replaced by an equivalent quantity of a metal or other basic radical; e.g.—

1. The one atom of hydrogen in hydrochloric acid (HCl) may be replaced by sodium, producing the salt sodium chloride (NaCl).

2. The one atom of hydrogen in nitric acid (HNO₃) may be replaced by silver, producing the salt silver nitrate (AgNO₃).

3. One atom of hydrogen in acetic acid (HC₂H₃O₂)[6] may be replaced by the basic radical ammonium (NH₄), producing the salt ammonium acetate (NH₄C₂H₃O₂).

Acids which, like those mentioned in the foregoing examples, contain one atom of replaceable hydrogen are called monobasic; those which contain two such atoms (e.g. sulphuric acid, H₂SO₄; tartaric acid, H₂C₄H₄O₆),[7] dibasic; those which contain three such atoms (e.g. phosphoric acid, H₃PO₄; citric acid, H₃C₆H₅O₇),[7] tribasic; and so on with acids of higher basicity. Acids of greater basicity than unity are frequently termed polybasic.

Besides containing replaceable or basic hydrogen, acids are further characterised by the property of combining with alkaloids to form salts; e.g.—

Sulphuric Acid.	Quinia.
H₂SO₄	+ 2C₂₄H₂₄N₂O₂	=

Quinia Sulphate.

(C₂₀H₂₄N₂O₂)₂ . H₂SO₄

Acetic Acid.	Morphia.
HC₂H₃O₂	+ C₁₇H₁₉NO₃	=

Morphia Acetate.

C₁₇H₁₉NO₃ . HC₂H₃O₂

Fatty Acids. Acids separable from fats or oils; e.g. stearic acid, oleic acid, butyric acid, &c.

Mineral Acids. Acids chiefly or wholly derived from the mineral kingdom. In medicine, sulphuric, hydrochloric, and nitric acids, are commonly so called.

Organic Acids. Acids formed by, or derived from organic substances; e.g. acetic acid, tartaric acid, uric acid, &c.

Pyro-acids. Acids resulting from the decomposition by heat of other acids, e.g. gallic acid, when heated, yields pyro-gallic acid.

ACIDIFICA′TION. [Eng., Fr.] Syn. Acidifica′tio, L. In chemistry, the act, process, or state of acidifying, or of making, becoming, or impregnated with acid.

ACIDIM′ETER. Syn. Acidom′eter; Acidime′trum, &c., L.; Acidimètre, Fr. An instrument or apparatus employed in acidimetry.

The ordinary acidimeters of the chemist are small tubes, constructed to hold exactly 1000 grains of distilled water, at 60° Fahr., within the limits of their scale, which is accurately graduated into 100 divisions. They are used to contain the alkaline solutions (TEST-LIQUORS, NORMAL or STANDARD SOLUTIONS) employed in the following processes.

Beaumé’s Acidimeter, and others of the same class, are HYDROMETERS, and are described under that ‘head.’

ACIDIM′ETRY. Syn. Acidom′etry; Acidime′tria, &c., L.; Acidimétrie, Fr. The estimation of the strength or quantity of acid, in a free state, contained in any liquid. It is the reverse of ‘alkalimetry.’ Acidimetrical assays are understood to refer to the relative strengths of the same acids (i. e., the quantity of real acid of the same kind contained in the solutions examined), and not to the comparative strengths of acids of different composition or names.

Acidimetrical processes. These are founded chiefly on the capacity of the acids to saturate the bases; and, in some of the liquid acids, on the specific gravity.

1. The sample of the acid to be examined (100 gr., or any convenient aliquot part thereof) is placed in a suitable glass vessel, and if it be one of the stronger acids, diluted with six or eight times its weight of water, or if solid (as oxalic, or citric acid), dissolved in a like quantity. This liquid is then exactly neutralised with an alkali.

This point is usually determined, by the addition of a small quantity of litmus solution, which turns just blue when the solution is neutralised, but when a carbonate is used for the alkaline solution, the acid must be boiled a short time after each addition to expel the carbonic acid. The quantity of the alkaline solution consumed for this purpose represents an equivalent quantity of acid, and thus gives us the acid content of the sample under examination. The common practice is to dissolve one equivalent of the alkaline test in grains or grammes in water, and to make up the solution to exactly 1000 parts by measure (i. e., 1000 ‘water-grains’ or grammes), so as to accurately fill the 100 divisions of an acidimeter; when the quantity, in grains or grammes, of the sample tested, bears the same proportion to the equivalent number of the acid under examination, that the number of acidimeter divisions of the test-liquor consumed bear to the per-centage of acid sought. Thus:—suppose 50 gr. of a sample of sulphuric acid take 25 acidimeter divisions (300 parts or water-grains measure) of the test-liquid to neutralise it, what is its content of real acid?

The equivalent of sulphuric acid is 49 (half its atomic weight); so, by the rule of proportion,

If the 1000 parts or grain-measures, instead of the number of the acidimeter divisions, be taken for the calculation, it will, of course, be necessary to point off the first right-hand figure of the result as a decimal. Thus; repeating the above example—

Or, since the equivalent of the test-liquid is 100, it will bear the same proportion to the equiv. of the acid examined as the number of the acidimeter divisions of the test-liquid28 consumed in neutralising 100 gr., do to the per-centage sought. Thus:—50 gr. of hydrochloric acid take 45 acidimeter divisions to effect neutralisation, what is its real strength?—The equiv. of hydrochloric acid is 36·5: therefore—

16·425 × 2 = 32·85%

Some operators prefer employing 100 gr. instead of the equivalent weights of the given tests in making their test-solutions, in which case each gr. or 1000th part represents ¹⁄₁₀th, and each acidimeter degree 1 gr. of the alkali or carbonate employed; when a similar proportion will obtain to that first above given.

In technical analysis it is more convenient if the number of acidimeter divisions of the ‘test-liquid’ consumed express the per-centage strength of the acid, without further calculation. For this purpose the number of grains of the acid taken for the assay should correspond to the equivalent number of such acid (see Table I, below); or to some convenient aliquot part of it, as the ¹⁄₂, ¹⁄₄, ¹⁄₅, or ¹⁄₁₀th; the per-centage answer, in the last case, being doubled, quadrupled, &c., according to the aliquot part taken. The reason of this is obvious.

For the test-solutions, ammonia, and the dry and crystallised carbonates and bicarbonates of potash and soda, are used, and are made by dissolving in water their constituents except ammonia, of which 1000 grains, or one litre, of solution of specific gravity 0·992 contains exactly one equivalent.

53 grains (or grammes) of pure anhydrous carbonate of soda, prepared by gradually heating to redness the crystallised salt, constitute one equivalent (half the atomic weight), and 69 grains (or grammes) of pure dry carbonate of potash. Of the crystallised salt 143 grains of carbonate of soda will be required, and 84 grains (grammes) of the crystallised bicarbonate of soda, and 100 of the crystallised bicarbonate of potash. Occasionally solutions containing in one thousand parts, 50 of pure carbonate of lime or chalk, or 28 of pure caustic lime, are used.

Besides these, a process known as Kiefer’s is practised, and an ammoniacal solution of oxide of copper is employed as the ‘test-liquor,’ and the ‘point of neutralisation’ is known by the turbidity observed as soon as the free acid present is completely saturated.

The normal solution or test-liquor is prepared by adding to an aqueous solution of sulphate of copper, pure ammonia water, until the precipitate, which at first forms, is just redissolved, carefully avoiding excess. Or better, by adding a rather strong solution of sulphate of copper, to a quantity of a rather strong solution of ammonia containing exactly 17 gr., or one equiv. of pure ammonia, as long as the precipitate which forms is redissolved on agitation; the resulting liquid being afterwards diluted with pure distilled water, until it accurately measures 1000 water-grains, or fills 100 divisions of an acidimeter, at 60° Fahr. In either case, the strength of the resulting ‘test-solution’ must be carefully determined by means of standard sulphuric acid, and adjusted, if necessary.

This method answers well with all the stronger acids (excepting oxalic acid), even when dilute; and it has the advantage of not being affected by the presence of a neutral metallic salt with an acid reaction, as sulphate of copper, or of zinc.

Besides this process a solution of lime in sugar may be used, as proposed by M. Peligot, and made as follows:—

Pure caustic lime is carefully slaked by sprinkling with water, and 50 grains (or grammes), made up by water to a milky solution, and 100 grains of pure sugar candy dissolved in 1000 grains of water, are added, and the whole well shaken. It is allowed to settle in a closed bottle, and the clear solution poured off and diluted, until 1000 grains neutralise exactly 100 grains of pure hydrochloric acid of sp. gr. 1·1812. Of course it only answers with acids whose calcium salts are readily soluble in water.

The test-liquors or standard solutions of the above methods are made up so as to weigh exactly 1000 grains, instead of to ‘measure’ 100 acidimeter divisions. Every grain of the test-liquor thus represents ¹⁄₁₀th gr. of alkali; and every 10 gr., 1 gr. of alkali; or respectively, ¹⁄₁₀th per cent. and 1 per cent. The vessel used for containing the solutions is carefully weighed whilst empty, and 1000 gr. being placed in the opposite scale, the test-solution, containing exactly one equivalent of base, is poured in, and the whole made up with distilled water (if necessary) so as to restore the balance to an equilibrium. After the process of neutralisation, the acidimeter, with its contents, is again placed in the scales; its previous weight still remaining there. The number of grains required to restore the equilibrium of the balance (i.e., the loss of weight), gives the exact weight of the test-liquor consumed. In all other respects the process is the same as in the ‘volumetrical method’ already described.

Another method for estimating the strength of the sample of acid is by weighing the amount of carbonic acid expelled during saturation. (Method of Fresenius and Will.) This depends on the weight of gaseous carbonic acid which a given weight of the acid-sample under examination is capable of expelling from pure bicarbonate of soda (or of potash), which is estimated by the loss of weight in the acidimeter, or apparatus, after the gas, rendered perfectly dry by passing through sulphuric acid, has escaped into the air.29

17	gr.	of pure ammonia.[8]	are exactly neutralised by	51 Acetic acid (anhydrous).
31	”	anhydrous soda.[9]		60 Acetic acid (crystallised or glacial).
40	”	hydrate of soda.[9]		99 Arsenious acid (dry).
53	”	dry carbonate of soda.[10]		35 Boracic acid (anhydrous).
143	”	crystallised carbonate of soda.[11]		62 Boracic acid (crystallised).
84	”	crystallised bicarbonate of soda.		22 Carbonic acid (dry).
47	”	anhydrous potassa.[9]		67 Citric acid (crystallised).
56	”	hydrate of potassa.[9]		85 Gallic acid (dried at 212°).
69	”	dry carbonate of potassa.[10]		94 Gallic acid (crystallised).
100	”	crystallised bicarbonate of potassa.		127¹⁄₂ Hydriodic acid (dry or gaseous).
50	”	pure chalk or pure marble.		27 Hydrocyanic acid (anhydrous).
28	”	pure caustic lime.		36¹⁄₂ Hydrochloric acid (dry or gaseous).
37	”	hydrate of lime (fresh).		109¹⁄₂ Hydrochloric acid (liquid, sp. gr. 1·162).
44	”	dry carbonic acid (when the bicarbonate of potassa or soda is used for testing in the process of Fresenius and Will).		166¹⁄₂ Iodic acid.
22	”	dry carbonic acid (when a dry carbonate is used).		54 Nitric acid (anhydrous).
				67¹⁄₂ Nitric acid (liquid, sesquihydrated, sp. gr. 1·5033 to 1·504).
				72 Nitric acid (liquid, binhydrated, sp. gr. 1·486).
				90 Nitric acid (liquid, sp. gr 1·42).
				36 Oxalic acid (anhydrous).
				63 Oxalic acid (crystallised).
				72 Phosphoric acid (anhydrous).
				81 Phosphoric acid (glacial).
				50 Succinic acid (dry or anhydrous crystals).
				59 Succinic acid (ordinary crystals).
				40 Sulphuric acid (anhydrous).
				49 Sulphuric acid (liquid, monohydrated, sp. gr. 1·8485).
				75 Tartaric acid (crystallised).
				12 Tannic acid (carefully dried).

[8] 1000 water-grains measure of pure liquor of ammonia, sp. gr. 0·992, contains exactly 17 gr., or 1 equiv. of pure gaseous ammonia. A standard liquor of this strength may be most conveniently prepared by cautious dilution of a stronger solution, until a hydrostatic bead, corresponding to the sp. gr., floats indifferently in the middle of the new solution, at 60° Fahr. By keeping two hydrostatic beads in the solution—the one made barely to float, and the other barely to sink—we shall always be able to detect any change of strength or temperature which it may suffer; since the “loss of a single hundredth part of a grain of ammonia per cent., or the difference of a single degree of heat, will cause the beads to” vary their positions. To preserve its integrity it must be kept in a well-stoppered bottle. (See below.)

[9] These substances, as well as ‘test-solutions’ containing them, must be perfectly free from carbonic acid, and must be carefully preserved to prevent the absorption of carbonic acid from the atmosphere. Mohr states that a dilute solution of either of them is best preserved in a flask or bottle well closed with a cork fitted with a small bulb tube (resembling a chloride of calcium tube), filled with a finely triturated mixture of sulphate of soda and caustic lime, and bearing a very thin open tube in the exit aperture. Fresenius, and most other foreign chemists, prefer ‘test-solutions’ of pure soda. With test-solutions containing caustic alkalies, exact neutralisation of an acid is not only more easily effected, but more readily perceived, particularly when either solution is tinted with litmus.

Oper. A determined amount of the acid under examination is accurately weighed into the flask A (see engr.); and if it be a concentrated acid, or a solid, it is mixed with or dissolved in 6 or 8 times its weight of water. The little glass tube (e) is then nearly filled to the brim with pure bicarbonate of soda, in powder, and a fine silken thread is tied round the neck of the tube, by means of which it can be lowered down into the flask (A), so as to remain perpendicularly suspended when the cork is placed in the latter; the cord being held between the cork and the mouth of the flask. The flask (B) is next about half filled with oil of vitriol, and the tubes being arranged in their places, as represented in the engr.; and time having been allowed for the mixture of acid and water to cool completely, after the increase of heat caused by mixing, the whole apparatus is very accurately weighed. The cork in the flask (A) is then slightly loosened, so as to allow the little tube containing the bicarbonate of soda to fall into the acid, and is again instantly fixed AIR-TIGHT in its place. The evolution of carbonic acid now commences, and continues until the acid in the flask (A) is neutralised. When this takes place, which is easily seen by no bubbles being emitted on shaking the apparatus, the flask (A) is put into hot water (120° to 130°30 Fahr.), and kept there, with occasional agitation, until the renewed evolution of gas has completely ceased. The little wax stopper is then taken off the tube (a), the apparatus taken out of the hot water, wiped dry, and suction applied, by means of a perforated cork, or a small india-rubber tube, and the mouth, to the end of the tube (d), until the sucked air no longer tastes of carbonic acid. The whole is then allowed to become quite cold, when it is replaced in the balance (the other scale still containing the original weights), and weights added to restore the equilibrium.

The loss of weight represents the exact quantity of dry carbonic anhydride, or anhydrous carbonic acid gas, that has been expelled from the bicarbonate of soda, by the action of the acid in the sample examined.

The quantity of real acid it contained is then deduced by the following calculation:—One equivalent of gaseous carbonic anhydride, or anhydrous carbonic acid (= 44) bears the same proportion to one equivalent of the acid in question, as the amount of the carbonic anhydride expelled does to the amount of the acid sought. Thus, suppose a dilute sulphuric acid expels 3 gr. of carbonic anhydride, the arrangement is—

Consequently the sample operated on contained 3·5 (nearly) grains of true sulphuric acid.

Instead of the above calculation, we may multiply the weights of the respective acids required to expel 1 gr. of carbonic acid (as exhibited in the following table) by the number of gr. of dry carbonic acid evolved during the above operation. The product represents the per-centage strength, when 100 gr. of the acid have been examined. When only 50, 25, 20, or 10 gr. have been tested, this product must, of course, be doubled, quadrupled, &c., as the case may be.

	Multipliers.
Acetic acid (anhydrous)	1·159
Acetic acid (hydrated or glacial)	1·364
Citric acid (crystallised)	1·523
Hydrochloric acid (dry or gaseous)	·829
Hydrochloric acid (sp. gr. 1·16)	2·478
Nitric acid (anhydrous)	1·227
Nitric acid (sp. gr. 1·5)	1·523
Nitric acid (sp. gr. 1·42)	2·045
Oxalic acid (crystallised)	1·432
Sulphuric acid (anhydrous)	·909
Sulphuric acid (sp. gr. 1·8485)	1·114
Tartaric acid (anhydrous)	1·500
Tartaric acid (crystallised)	1·705

Even this easy calculation may be avoided, in technical analysis, by simply taking for the assay such a weight of the respective acids as is capable of disengaging exactly 10 gr. of dry carbonic acid from the bicarbonate. In this case, the loss of weight in grains, from the operation, multiplied by 10, at once indicates the exact per-centage strength sought. The proper weight of any acid to be taken to give per-centage results is found by simply dividing ten times the equiv. of that acid by 44. For, taking sulphuric acid as an example,

	Grains.
Acetic acid (anhydrous)	11·59
Acetic acid (hydrated or glacial)	13·64
Citric acid (crystallised)	15·23
Hydrochloric acid (dry or gaseous)	8·29
Hydrochloric acid (sp. gr. 1·16)	24·78
Nitric acid (anhydrous)	12·27
Nitric acid (sp. gr. 1·5)	15·23
Nitric acid (sp. gr. 1·42)	20·45
Oxalic acid (crystallised)	14·32
Sulphuric acid (anhydrous)	9·09
Sulphuric acid (sp. gr. 1·845)	11·14
Tartaric acid (anhydrous)	15·00
Tartaric acid (crystallised)	17·05

2. A convenient modification of the preceding method of acidimetry consists in using the common apparatus figured in the margin and employing fused chloride of calcium to dry the evolved carbonic acid gas, instead of concentrated sulphuric acid. The mode of conducting the process and obtaining the results is precisely the same as in that last explained, and need not, therefore, be repeated. In this case, however, suction must be applied to31 the small tube (g), instead of (d) in the accompanying engraving.

Obs. These methods, though apparently complicated, are not difficult to perform, when once well understood. The application of heat after the completion of the operation is indispensable, as, if it were neglected, from 0·3 to 0·4 of a gr. of carbonic acid would be retained in the liquid. The bicarbonate of soda must be pure, and perfectly free from any neutral carbonate or sesquicarbonate of soda. To ensure this, the bicarbonate of commerce is reduced to a uniform powder, put into a glass jar, and covered with its own weight of cold distilled or rain water, and allowed to stand for twenty-four hours, with frequent stirring. It is then placed upon a funnel, the tube of which is stopped with loose cotton, so as to allow the lye to drain off. It is next washed several times with small quantities of cold distilled or rain water, and after being dried by pressure between some sheets of blotting-paper, without the aid of heat, is kept for use in a well-closed glass bottle. Before use, it may be tested to ascertain its purity. If pure, it neither reddens turmeric paper, nor gives a brick-red precipitate with a solution of bichloride of mercury. Pure bicarbonate of potassa may be used instead of bicarbonate of soda; but in either case it is always proper to use an excess, so as to leave some undecomposed carbonate after the operation has ended. The presence of a little sodium chloride or sulphate in the bicarbonate will not interfere in the least, but the absence of every trace of neutral carbonate is a sine quâ non.

The two above methods of estimating the amount of acid are only superior to the generally used methods first described, when the presence of colouring matter interferes with the reaction of the litmus used to show the point of neutralisation.

Observations. When great accuracy is required in conducting the neutralisation of the solution in estimating volumetrically with litmus as an indicator, it is proper to prepare and keep standard solutions of sulphuric acid and oxalic acid, with which occasionally to try the alkaline test-liquor. The only difficulty in the process is to avoid over-saturation of the acid-sample. Great care must be taken not to exceed the precise point of neutralisation of the acid. After adding each portion of the test-liquor, the solution should be well stirred up, and as soon as the effervescence becomes languid the greatest caution must be observed in adding more. The proper point is arrived at when the liquor ceases to redden litmus, and does not alter the colour of turmeric paper; if it turns the latter brown, too much of the test-liquid has been added, and the operation becomes useless. Towards the end of the experiment, when great precision is required, a gentle heat may be applied, in order to expel the free carbonic acid in the liquor; but otherwise this is unnecessary. The peculiar soapy odour gradually acquired by the liquor as it nears saturation will materially assist the operator when testing vinegars, and some of the other vegetable acids. A good method is to tint either the acid-sample or the test-liquid with a few drops of litmus, as noticed under Acetimetry; when the reddish shade will gradually deepen into ‘purple,’ or the purple into ‘red,’ as the point of saturation is approached; and the blue colour will be perfectly restored as soon as this point is reached. Dr Ure recommends keeping the ammonia-test ready tinged with litmus, and the same applies to other test-liquors.

In commerce, the strength of acids is frequently reckoned with reference to a standard, termed 100 acidimetric degrees. This is taken from the circumstance that 91 gr. of commercial oil of vitriol, of a sp. gr. of 1·845, exactly saturate 100 gr. of dried carbonate of soda. An acid requiring only 35, 50, or any other number of grains of the carbonate to saturate it, is in like manner termed of so many degrees strong; the number of grains representing in each case an equal number of degrees. This method originated with the French chemists, and though only conventional, and principally confined to commercial purposes, is especially adapted to practical men but little conversant with chemistry, yet very ready in retaining or calculating anything on the centesimal scale, from its similarity to monetary language and reckoning.

ACID′ITY. Syn. Acid′itas, L.; Acidité, Fr.; Säure, Ger. In chemistry, the state of being acid. In physiology, &c., the impression given to the organs of taste by tart or acid substances. Sourness. See Fermentation, Malt-liquors, Wines, &c.

Gas′tric Acidity. Acidity of the stomach; a common and well-known symptom of weak or disordered digestion.

Treat., &c. Small doses of absorbents or antacids, three or four times daily, to which some tonic bitter, as calumba, cascarilla, chamomile, gentian, or orange-peel, may be added. Stomachic stimulants, as capsicum, ginger, mustard, or wine, &c., taken with, or after, meals, are also useful. The diet should be light and nutritious; and acescent vegetables,32 over-ripe fruit, and weak new beer or other liquors avoided as much as possible. The bowels should be kept regular, but not open, by the occasional use of mild aperients, as rhubarb, aloes, castor oil, senna, or mercurial pill, or compounds containing them. Excessive looseness or diarrhœa may be checked by a few doses of carbonate of soda, chalk-mixture, or astringents.

In INFANCY this affection is usually accompanied by restlessness, continual crying, drawing up of the legs forcibly towards the body, hiccups, vomiting, diarrhœa, sour eructations, griping pains, green stools, and debility; often followed, when the irritation is considerable, by convulsions. The treatment consists in relieving the bowels of all offending matter by a few doses of rhubarb-and-magnesia. The looseness or diarrhœa may be checked by a few small doses of carbonate of soda or chalk mixture; or better, in an infant which is fed by lime-water (1 or 2 fl. oz.) mixed with as much milk. Two or three drops of caraway, cinnamon, dill, or peppermint water, on sugar (not with the food) will tend to promote the expulsion, and prevent the undue generation of gases. The flatulence usually disappears with the acidity. The occasional administration of 1 to 3 gr. of quicksilver-with-chalk (‘grey powder’), will frequently remove the complaint, and prevent its recurrence, when all other means fail. The diet of both nurse and infant should be carefully regulated.

Treatment for Horses. Alkalies, their carbonates and bicarbonates; alterative doses of aloes with alkalies; chalk, carbonate of magnesia; mineral acids; bismuth, arsenic, nux vomica, or strychnia.

ACIDS, EFFECTS OF, ON VEGETATION. This subject has been ably investigated of recent years by Dr Angus Smith and Mr Rothwell, and the practical importance of their labours is shown by the circumstance that an Act of Parliament passed in 1875 renders it penal for the proprietors of alkali works to condense not less than 95 per cent. of the hydrochloric acid evolved in the process of manufacturing ‘soda,’ also to allow air, smoke, or chimney gases to escape into the atmosphere containing more than one fifth of a grain of hydrochloric acid per cubic foot. Every owner of an alkali work is likewise required to ‘use the best practical means of preventing the discharge into the atmosphere of all other noxious gases arising from such work, or of rendering such gases harmless when discharged.’

The injurious effects of acids on vegetation are indicated chiefly by the shrivelled-up appearance which the leaves of herbage, trees, &c., exhibit in the vicinity of chemical works in which the condensation of noxious gases (hydrochloric acid, sulphurous acid, sulphuric acid, sulphuretted hydrogen, nitric acid, and oxides of nitrogen and chlorine) is not effectually carried out. According to Mr Rothwell, ‘in fields exposed to acid vapours handfuls of dead grass may be pulled up in the spring, smelling strongly of the vapour, and that trees, under similar influences, become bark-bound.’

The following is a list of trees arranged in the order of their susceptibility. (Rothwell.)

Forest Trees. Larch, spruce fir, Scotch fir, black Italian poplar, Lombardy poplar, ash, oak, elm, birch, alder, sycamore.

Fruit Trees. Damson, greengage, Halewood plum, Jacob plum, pears, apples, cherries.

Shrubs, Evergreens, and Wild Plants. British laurels, Portugal laurels, Aucuba Japonica, Barberry evergreen, hazel, guelder rose, sloe thorn, hawthorn, raspberries, gooseberries, blackberries, gorse, hollies.

Farm Crops. Potatoes, mangel, white clover and rhubarb, red clover, trefoil, rye-grass, wheat, oats, barley, common turnips, swedes.

Second list of Plants affected by Noxious Vapours, mixing the classes according to the effects produced on each.

Clover (white and red), trefoil, rye-grass, poplars, hawthorn, potatoes—receive damage in winter to roots.

III. Laurels (British and Portugal), aucubas, yews, holly, gorse—receive damage in winter, but more in summer.

IV. Ashes, oaks, hazels, horse-chestnuts, walnuts, Spanish chestnuts, sloe thorn.

V. Swedish turnip and cabbages, damson, other fruit trees, beech, elm, birch, alder, sycamores.

ACIDULATED. Syn. Acidulatus, L.; Acidulé, Fr. Blended or flavoured with an acid; made slightly sour. See Kali (Acidulated), Drops, Lozenges, &c. In chemistry, the addition of an acid to a neutral or alkaline liquid until it reddens blue litmus paper.

ACNE. [Syn. Pimpled Face.] There are two forms of this affection. 1st. In young persons of both sexes; generally in phlegmatic habits. The disease shows itself by hard pimples, with a small black spot on the apex, unaccompanied with redness or inflammation at first, but after a while they become red and inflamed, and sometimes suppurate, with a greasy look of the skin between them. In this form of acne the black spots should be picked out with a needle or a small pair of33 tweezers. A long piece of thick matter, like a worm, is extracted; but is no worm. Afterwards wash the face with water in which a small piece of Quillar bark has been steeped, or with bitter almond emulsion, or borax, one drachm, water 4 oz. When there is no inflammation, use Eau de Cologne, or a few drops of oil of rosemary dissolved in spirit of wine, taking a small dose of magnesia in the morning, or milk of sulphur daily. When the pimples are very sluggish the cautious application of tincture of iodine, or of ointment of nitrate of mercury, will be found serviceable.

2nd. Arises from intemperance. In this case a gradual change of habits is essential. The use of soap should be avoided, and recourse had to warm fomentations of slippery elm, or thin oat gruel. The following should be applied to the pimples:—Cold cream, 1 oz., Goulard’s extract 20 drops, mixed together; or lemon juice diluted, or solution of borax in water. The internal administration of the mineral acids combined with bitter tonics, or small doses of iodide of potassium, will be found effectual.

Treatment. Fomentations, poultices, chloride of zinc solution externally; sulphur and alteratives internally.

ACOLOGY. Syn. In medicine, the doctrine of, or a discourse on, remedies or the materia medica.

ACONITE. (-nite). Syn. Acon′itum, L.; Aconit, Fr.: Akonitum, Eisenhut, Sturmhut, Ger. Monkshood; wolfsbane. In botany, a genus of exogenous plants. Nat. ord., Ranunculaceæ; Sex. syst., Polyandria Trigynia. They are characterised by showy purple or yellow helmet-shaped flowers growing in panicles, deeply cut leaves, and perennial (usually) tap-shaped or tapering roots. The whole plant is highly poisonous, the roots being more poisonous than the leaves. In medicine and materia medica, the plant Aconitum Napellus (which see).

Symptoms. Numbness and tingling in the mouth and throat, which are parched; followed by giddiness, dimness of sight, and (sometimes) delirium, but seldom complete coma; there is numbness and tingling of the limbs, a loss of power in the legs, (in some cases) frothing at the mouth, severe abdominal pains, nausea, vomiting, and diarrhœa; tremors or twitchings of the voluntary muscles, (sometimes) convulsions (in animals, but not in man); sharp cries; pupil (generally) dilated, very rarely contracted; pulse fitful and sinking; skin cold and livid; difficulty of breathing; general prostration; loss of sensation or feeling, insensibility, general trembling, fainting, and sudden death. The eyes are often glaring; and, in some cases, the patient is completely paralysed, yet retains consciousness to the last. The case generally proves fatal in from 1 to 8 hours. If it last beyond this period there is hope of recovery. (Fleming.)

Antidotes. Ammonia, or brandy, with artificial respiration if necessary: cold affusion and friction, with warm towels to the back and limbs. See Alkaloids.

ACONITE LEAVES (B. Ph.). Syn. Aconiti folia, L. The fresh leaves and flowering tops of aconitum napellus, Linn., gathered when about one third of the flowers are expanded, from plants cultivated in Britain.

Char. Leaves smooth, palmate, divided into five deeply cut wedge-shaped segments; excizing slowly, when chewed, a sensation of tingling. Flowers numerous, irregular, deep blue, in dense racemes.

ACONITE ROOT. (B. Ph.). Syn. Aconiti radix, L. The dried root of aconitum napellus. Imported from Germany, or cultivated in Britain, and collected in the winter or early spring before the leaves have appeared.

Prep. Aconitia, the active principle; Linimentum Aconiti, 1 ounce to 1 fluid ounce; Tinctura Aconiti, 54¹⁄₂ grains to 1 fluid ounce.

Char. Usually from one to three inches long, not thicker than the finger at the crown, tapering, blackish-brown, internally whitish. A minute portion, cautiously chewed, causes prolonged tingling and numbness.

ACONITIA. C₃₀H₄₇O₇N. (B. P.) Syn. Aconitia, L. An alkaloid obtained from aconite.

Aconite root, in coarse powder, 14 pounds.
Rectified spirit	of each a sufficiency.
Distilled water
Solution or ammonia
Pure ether
Diluted sulphuric acid

Pour upon the aconite root three gallons of the spirit, mix them well, and heat until ebullition commences; then cool and macerate for four days. Transfer the whole to a displacement apparatus, and percolate, adding more spirit, when requisite, until the root is exhausted. Distil off the greater part of the spirit from the tincture, and evaporate the remainder over a water bath until the whole of the alcohol has been dissipated. Mix the residual extract thoroughly with twice its weight of boiling distilled water, and when it has cooled to the temperature of the atmosphere, filter through paper. To the filtered liquid add solution of ammonia in slight excess, and heat them gently over a water bath. Separate the precipitate on a filter, and dry it. Reduce this to coarse powder, and macerate it in successive portions of the pure ether with frequent agitation. Decant the several products, mix and distil off the ether until the extract is dry. Dissolve the dry extract in warm distilled water acidulated with the sulphuric acid; and, when the solution is cold, precipitate it by the cautious addition of solution of ammonia diluted with four times its bulk of distilled water. Wash the precipitate on a filter with a small quantity of cold distilled34 water, and dry it by slight pressure between folds of filtering paper.

Characters and Tests. A white, usually amorphous, solid, soluble in 150 parts of cold, and 50 of hot water, and much more soluble in alcohol and in ether; strongly alkaline to reddened litmus, neutralising acids, and precipitated from them by the caustic alkalies, but not by carbonate of ammonia or the bicarbonates of soda or potash. It melts with heat, and burns with a smoky flame, leaving no residue when burned with free access of air. When rubbed on the skin it causes a tingling sensation, followed by prolonged numbness. It is a very active poison.

ACONITIA, CRYSTALLISED. C₂₇H₄₀NO₁₀. Exhaust the root of wild aconite, carefully picked and powdered, with very strong alcohol, to which 1 per cent. of tartaric acid has been added. Distil at a gentle heat, and sheltered from the air, to recover the alcohol. Treat the extract with water to separate all the fatty and resinous matters. The solution which contains the aconite in the state of acid tartrate is first shaken with ether to remove colouring matters, and then the alkaloid is set free by the addition of alkaline bicarbonate, until the cessation of effervescence. A fresh treatment with ether of this alkaline solution removes the alkaloid, which crystallizes upon the concentration of the ethereal liquid, with an addition of petroleum spirit. The crystals are colourless tables, rhombic or hexagonal, according to the modifications produced principally in the acute angles. Crystallized aconitia is soluble in alcohol, ether, benzine, and chloroform; insoluble in petroleum oils and glycerine.

Aconitia Nitrate, Crystallised. Crystallised aconitine q. s.; nitric acid, sp. gr. 1·442, q. s. Saturate the nitric acid with the aconitine and evaporate. Voluminous crystals are easily obtained (from ‘Formulæ for New Medicaments adopted by the Paris Pharmaceutical Society’).—‘Pharm. Journal.’ Owing to the decomposition which this alkaloid undergoes in the animal organism, as well as to its liability to decompose during the process of evaporation, and exposure to the air, it often becomes extremely difficult, if not impossible, to obtain it in a separate state in conducting a post-mortem examination. The physiological effects seem to furnish the most prominent and characteristic evidence of its presence in such cases, or at any rate these may serve as a valuable guide to the toxicologist.

Uncrystallised aconitia is sometimes contaminated with delphinia, as well as with aconella, another constituent of aconite root. For the dissection of these see Alkaloids. One fiftieth of a grain of aconitia is stated to have killed a dog.

ACONITIC ACID. (Identical with Pyrocitric Acid.) An acid extracted by Peschier from aconitum napellus, and by Bracconnot from equisetum fluviatile. It exists in these plants chiefly in the form of aconitate of calcium.

ACONI′TUM. [L.] Aconite. The pharmacopœial name of aconitum napellus(see below).

Aconitum Ferox. (Ind. P.) Habitat. Temperate and sub-Alpine Himalaya, at 10,000 to 14,000 feet elevation, from Gurhwal to Sikkim.

Officinal part. The dried root (Aconiti ferocis Radix), in common with those of other Himalayan species, viz., aconitum napellus, a. palmatum, and a. luridum, constitutes the drug well known in the bazaars of Upper India under the Hindostani name of Bish or Bikh.

It occurs in the form of tuberous roots of a more or less conical form, from two to three inches in length, and from half an inch to one inch in thickness at their upper end. They have usually a shrunken appearance, and are covered with a dark shrivelled bark; fracture shining and resinous; sometimes waxy, varying in colour from pale to deep brown. Some specimens are white and spongy; and these, it is asserted, are superior in activity to the more compact kinds. Inodorous; taste at first slightly bitter, leaving a peculiar sense of numbness on the tongue and fauces. Active principle, aconitia.

Medical Properties and Uses. Similar to those of aconitum napellus of Europe. Preparations. This root may be advantageously used for the manufacture of aconitia, the proportion of this alkaloid being much larger than in the European drug; and also for the preparation of Linimentum Aconiti. From its greater activity, however, it is unsuited for the preparation of this tincture, which is intended for external use.

Aconitum Hetorophyllum. (Ind. P.) Habitat. Western temperate Himalaya, at 8000 to 13,000 feet elevation; from Indus to Kumaon. Officinal part. The dried root (Aconiti heterophylli Radix). Ovoid tuberous roots, tapering downwards to a point, from one to one and a half inches or more in length, and from three eighths to half an inch in thickness. The surface, which is covered with a thin greyish epidermis, is slightly wrinkled longitudinally, and marked here and there with root scars. It is inodorous, and of a bitter taste, devoid of acridity. Does not contain aconitia. It may be readily distinguished from other roots sold in the bazaars under the same vernacular name (Atis) by its characteristic bitterness. Properties. Tonic and antiperiodic. It may be administered internally with safety, as it contains no poisonous principle. Therapeutic uses. In convalescence35 after debilitating diseases, and in intermittent and other paroxysmal fevers, it has been found an efficient remedy. Doses. Tonic, 5 to 10 grains thrice daily; antiperiodic, 20 to 30 grains of the powdered root every three or four hours, irrespective of the presence of pyrexia.

Aconitum Napell′us. [Linn.] Syn. Aconi′tum, Ph. L., E., & D.; Aconitnapèl, chaperon de moine, Fr.; Eisenhut, Blauersturmhut, Ger. Early blue wolfsbane, or deadly aconite. Hab. Various parts of Europe; grows wild in England, flowering in June and July. The fresh and dried leaves (ACONITI FO′′LIUM), Ph. L. & E. The root (ACONITI ra′dix), Ph. L. & D. This is the species of aconite ordered in the pharmacopœias, and commonly used in medicine. When chewed it imparts a sensation of acrimony, followed by a pungent heat of the lips, gums, palate, and fauces, which is succeeded by a general tremor and chilliness. The juice applied to a wound or the unsound skin affects the whole nervous system. Even by remaining long in the hand, or on the bosom, it produces unpleasant symptoms. Fatal cases of poisoning, by eating the root in mistake for horseradish, have been common of late years. The two roots may be, however, easily distinguished from one another; when scraped aconite emits an earthy, and horseradish its well-known pungent odour. Moreover, the shape of the roots is very different. In the accompanying figure a represents aconite root, and b horseradish root.

The leaves should be gathered as soon as the flowers appear. The root should be taken up in autumn. When the whole plant is employed, it should be gathered as soon as the flowers begin to open. The strength (richness in aconitia) varies considerably with the time of the year. 1 oz. of the fresh root contains ¹⁄₄ to ³⁄₄ gr. of aconitia; 1 lb. of the dried English root contains from 12 to 36 gr. (Herapath). The leaves possess the greatest activity just before flowering; the root, after it. The root is at all times fully six times as strong as the leaves or herb. The wild plant contains much more aconitia than that which is cultivated. The herb, and all its preparations, lose their efficacy if long kept. The powder, more particularly, cannot be relied on. Mr Holmes says it is difficult to find in a commercial sample of aconite root one root in a dozen, which upon fracture appears sound and in good condition.

Uses, &c. In small doses aconite is narcotic, powerfully diaphoretic, and sometimes diuretic; in larger ones, the symptoms are similar to those produced by aconitia. It acts as a powerful sedative on the heart’s action, and destroys sensibility without disturbing the mental faculties. It has been given in chronic rheumatism, gout, paralysis, scirrhus, scrofula, cancers, venereal nodes, epilepsy, amaurosis, intermittents, &c.; but its exhibition requires the greatest possible caution. As a topical benumber it has been used with great advantage in painful affections depending on increased sensibility of the nerves. Externally it “is most valuable for the cure of neuralgic and rheumatic pains. In neuralgia, no remedy, I believe, will be found equal to it. One application of the tincture produces some amelioration; and after a few times’ use, it frequently happens that the patient is cured. In some cases, the benefit appears almost magical. In others, however, it entirely fails to give permanent relief.” “I do not think that in any (case) it proves injurious.” “When it succeeds, it gives more or less relief at the first application. When the disease depends on inflammation, aconite will be found, I think, an unavailing remedy.” “In rheumatic pains, unaccompanied with local swelling or redness, aconite is frequently of very great service.” (Pereira, iii, 691.) Dose, of the powder, 1 to 2 gr., gradually increased to 6 or 8. Dr Stocrk was the first who gave wolfsbane internally, about the year 1762. It has since been successfully employed in Germany in cases of chronic rheumatism, gout, &c., some of which were of long standing and had resisted every other remedy. In England it has been less extensively used.

Aconitum Panicula′tum. Panicled wolfsbane; a species formerly ordered in the Ph. L.; and, with a. napellus, also in the Ph. U. S. It is less active than the officinal species.

A′CORN. Syn. Glans. quer′cus, L. The seed or fruit of the oak. In the early ages of the world, acorns probably formed one of the principal articles of the food of man. (Ovid, Met., i, 106; Virgil, Georg., i, 8; &c.) In modern times, during periods of scarcity, they have been consumed as food on the Continent. Besides starch, they contain a peculiar species of sugar, which crystallises in prisms, and is unfermentable; they also contain tannic and gallic acids. Mannite and dulcose are the substances which it most nearly resembles. (M. Dessaignes.) During the autumn, acorns are said to be sometimes poisonous to cattle36 and sheep. Supposed cases of so-called acorn poisoning are best treated by withdrawing the supply of acorns, or removing the animals from the pastures on which the acorns fall, and by the administration of aperients, alkalies, and stimulants.

ACOTYLE′DONS (-ko-te-lē′-). Syn. Acotyle′dones (dŏn-ēz; L., prim. Gr.), Jussieu; Acotylédons, Fr.; Ohne samenlappen, Ger. In botany, plants whose seeds are not furnished with distinct cotyledons or seed-lobes. Acotyledonous plants form one of the two great divisions of the vegetable kingdom, according to the natural system. They are remarkable by increasing chiefly in length, by additions to their end; and not by addition to the outside, as in Exogens; nor to the inside, as in Endogens. They are also termed Asex′ual and Flowerless Plants, and answer to the Cryptogamia of the Linnean system. See Acrogens, Cellulares, Thallogens, &c.

ACOUS′TICS (-kow′-). The science of audition and sound; that branch of physics which treats of their cause, nature, and phenomena. The doctrine of the production and transmission of sound is termed Diacous′tics; that of reflected sound Catacous′tics.

Acoustics. In medicine, remedies employed to relieve deafness. See Deafness and Drops, Acoustic.

ACQUETTA. [It., Little Water.] Syn. Aqua Toffana; A. Toffania; Acquetta di napoli della Toffana, It. A celebrated poison, prepared by an Italian woman named Toffano, or Tophana, and in great request in Rome about the middle of the 17th century. The composition of this poison has been a matter of frequent controversy. Pope Alexander VII, in his proclamation, described it as “aquafortis distilled into arsenic.” This would produce a concentrated solution of arsenic acid. The Emperor Charles VI, who was governor of Naples during Toffano’s trial, declared to his physician, Garelli, that it was arsenic (arsenious acid) dissolved in aqua cymbalariá. According to Gerarde this cymbalarià was an aquatic species of pennywort, highly poisonous. The only objection to the latter statement is the smallness of the dose, regard being had to the comparative insolubility of arsenious acid; but if the woman Toffano prepared two poisons, as is probable from history—one, a single dose of which was fatal, and another, of which the dose required repetition, and which was more gradual in its activity—the discrepancy will be at once removed.

AC′RID. Syn. Ac′er, Ac′ris, L.; Acre (âcre), Fr.; Beissend, Scharf, Ger. In chemistry and medicine, sharp, pungent, acrimonious. Acrid substances are such as excite a sensation of pungency and heat when tasted, and which irritate and inflame the skin; as mustard, turpentine, cantharides, &c.

AC′RIMONY. Syn. Acrimo′nia, L.; Acrimonié, Acreté, Fr.; Scharfe, Ger. In medicine and chemistry, the quality or property of inflaming, irritating, corroding, dissolving, or destroying other bodies.

ACROGENS. Syn. Acrogenæ, L.; Acrogènes, Fr. In botany, acotyledonous or cryptogamic plants, in which stems and leaves, or an organisation approaching leaves, are distinguishable; which have stomates or breathing spores on their surface, are propagated by spores, and increase by the growth of the stem at the point only. Ferns and club-mosses are examples of this class of plants.

ACROLEIN. Syn. Acrylic Alcohol. This substance occurs amongst the products of decomposition when glycerine or any of its compounds is subjected to ordinary distillation. It derives its name from its violently irritant effect upon the mucous membranes of the eyes and respiratory organs. It is best prepared by the process of Redtenbacher (see ‘Leibig’s Ann.,’ xlvii, 114), by distilling in a capacious retort, a mixture of glycerine with phosphoric anhydride, or with hydric-potassic sulphate (the acid sulphate or bisulphate of potash); the vapours must be condensed in a properly cooled receiver, which is luted on to the retort and provided with a tube opening into a chimney having a good draught. The distilled liquid separates into two layers, the upper one consisting of acrolein, and the lower one of an aqueous solution of the same substance mixed with a quantity of acrylic acid. This distillate, after digestion with finely powdered litharge, with the object of neutralising the acid, must be rectified by the heat of a water bath: the acrolein so obtained must be submitted to a second rectification from calcic chloride. All these operations must be conducted in vessels filled with carbonic anhydride (carbonic acid) because acrolein becomes rapidly oxidized when exposed to the air.

Acrolein is a clear colourless liquid, lighter than water, boiling at about 125° F. It has great refracting power and a burning taste; when pure it is neutral to test paper.

AC′ROSPIRE (-spire). Syn. Acrospi′ra, L.; Plumule, Fr.; Blattkeim, Ger. The shoot or sprout of a seed, when it begins to grow; the part of a germinating seed termed the plume, or plumula.

When the growth of a seed begins to be developed, the germ, from which the stem originates, shoots forth under the form of a delicate curved fibre, which, gradually bursting its covering, makes its appearance at the end of the seed. The fibrils of the radicle first sprout forth from the tip of the grain; a white elevation appears, that soon divides into three or more radicles, which rapidly grow larger, and are succeeded by the plumula, which peeps forth at the same point, in the form of a pale green leaflet, which, twisting thence beneath the husk to the other end of37 the seed, ultimately bursts its prison-house, and becomes a perfect leaf. See Germination and Malting.

ACTINISM. Syn. Actinic Rays; Chemical Rays. A term given to a supposed principle accompanying the heat and light of the sunbeam. Actinic rays chiefly exist beyond the violet extremity of the solar spectrum, and are characterised by the power of exciting chemical change, e.g., the decomposition of certain silver salts (in photography); the combination of a mixture of chlorine and hydrogen, &c. The so-called vital functions of animals and plants are also greatly influenced by the actinic or chemical rays.

ACTINOGRAPH. An instrument for registering the intensity of the chemical influence (actinism) of the sun’s rays.

ACT, TOWNS IMPROVEMENT CLAUSES, 1847 (10 & 11 Vict., c. 34), The following provisions of this Act are incorporated in the Public Health Act, 1875, and refer exclusively to urban districts:—

2. With respect to improving the line of the streets and removing the obstructions.

4. With respect to precautions during the construction and repair of sewers, streets, and houses.

Notices for alterations under the 69th, 70th, and 71st sections, directions under the 73rd section, and orders under the 74th section of the said Towns Improvement Clauses Act, may, at the option of the urban authority, be served on owners instead of occupiers, or on owners as well as occupiers, and the cost of works done under any of these sections may, when notices have been so served on owners, be recovered from owners instead of occupiers; and when such cost is recovered from occupiers, so much thereof may be deducted from the rent of the premises where the work is done as is allowed in the case of private rates under the Act.

AC′TUAL. Real, effectual, absolute; as opposed to that which is merely virtual or potential. In surgery, a red-hot iron, or any other heated body, used as a cautery, is termed the ACTUAL CAUTERY; whilst a caustic or escharotic so employed is called the POTENTIAL CAUTERY.

ACUTE′. Syn. Acut′us, L.; Aigu, Fr.; Heftig, Hitzig, Spitzig, Ger. Sharp, pointed, sensitive. Applied to the senses, as acute hearing, eyesight, &c. In pathology, diseases exhibiting violent symptoms, and whose course is short, are said to be acute diseases.

ADAPTER. In chemistry, a tube placed between two vessels (commonly a retort and receiver) for the purpose of uniting them or increasing the distance between them, so as to facilitate the condensation of vapour in distillation. (See figure.)

ADDER’S TONGUE. Syn. Common adder’s tongue; Ophioglos′sum vulga′tum, Linn. A perennial plant, of the natural order Filices (DC.), growing wild in England. It is found in our woods and pastures, and flowers in May and June. It was once used to form a celebrated traumatic or vulnerary ointment and is still highly esteemed among rustic herbalists.

ADHE′SION (-hē-zhün). Syn. Adhæ′sio, L.; Adhesion, Fr.; Anhängung, Arxlebung, Ger. The act or state of sticking or being united.

Adhesion. In physics, the force with which bodies remain attached to each other when brought into contact; e.g., ink adheres to paper, paint adheres to wood, &c. It differs from ‘cohesion’ in representing the force with which different bodies cling together; whereas cohesion is the force which unites the particles of a homogeneous body with each other, e.g., particles of iron cohere and form a mass of iron; particles of water cohere and form a mass of water, &c.

Adhesion. In pathology, the morbid union, from inflammation, of parts normally contiguous but not adherent.

Adhesion. In surgery, the reunion of divided parts, by the adhesive inflammation; as when incised wounds heal by what is termed the ‘first intention.’

ADHE′SIVE. Syn. Adhæsi′vus, L.; Adhésif, Fr.; Adhäsive, Verwachsend, Ger. In pharmacy, &c., having the quality or property of sticking or adhering. Hence adhe′siveness.

AD′IPOCERE (-sēre). Syn. Grave-wax‡; Adipoce′′ra, L.; Adipocire, Fr.; Fetewachs, Ger. A substance resembling a mixture of fat and wax, resulting from the decomposition of the flesh of animals in moist situations, or under water. It is chiefly margarate of ammonium. Lavoisier proposed to produce this substance artificially, for the purposes of the arts. Attempts have since been made to convert the dead bodies of cattle (carrion) into adipocere, for the purposes of the candle-maker and the soap-boiler, but without success. Besides, dead animal matter38 can be worked up more profitably than in making artificial adipocere.

Hatchettine or rock-fat is sometimes called ‘adipocere’; and bog-butter is a substance nearly similar to it.

AD′JECTIVE. Syn. Adjecti′vus, L.; Adjectif, Fr. In dyeing, depending on another, or on something else; applied to those colours which require a base or mordant to render them permanent. See Dyeing.

AD′JUVANT. [Eng., Fr.] Syn. Ad′juvans, L.; Aidant, &c., Fr. Assistant; helping. (As a substantive—) In prescriptions, see Prescribing (Art of).

ADULTERATION. Strictly speaking, this term ought only to be applied to the practice of adding substances to articles of commerce, food or drink, for the purposes of deception or gain, but a wider interpretation is frequently placed on the word than the definition given by magistrates and analysts, these latter often regarding accidental impurity, or even, in some instances, actual substitution as acts of adulteration.

The following definition of an adulterated substance has been adopted by the Society of Public Analysts—

1. If it contain any ingredient which may render such article injurious to the health of a consumer.

2. If it contain any substance that sensibly increases its weight, bulk, or strength, or gives it a fictitious value, unless the amount of such substance present be due to circumstances necessarily appertaining to its collection or manufacture, or be necessary for its preservation, or unless the presence thereof be acknowledged at the time of sale.

3. If any important constituent has been wholly or in part abstracted or omitted, unless acknowledgment of such abstraction or omission be made at the time of sale.

1. If when retailed for medical purposes under a name recognised in the ‘British Pharmacopœia’ it be not equal in strength and purity to the standard laid down in that work.

2. If when sold under a name not recognised in the ‘British Pharmacopœia’ it differs materially from the standard laid down in approved works on materia medica, or the professed standard under which it is sold.

Limits. The following shall be deemed limits for the respective articles referred to:

Milk shall contain not less than 9·0 per cent., by weight, of milk solids, not fat, and not less than 2·5 per cent. of butter fat.

Skim Milk shall contain not less than 9·0 per cent. by weight, of milk solids not butter fat.

Tea shall not contain more than 8·0 per cent. of mineral matter, calculated on the tea dried at 100° C., of which at least 3·0 per cent. shall be soluble in water, and the tea as sold shall yield at least 30 per cent. of extract.

The practice of fraudulent adulteration has been indulged in for centuries. In every civilised state there have been enactments against it. The Romans had their inspectors of meat and corn. In England an Act to prohibit adulteration was passed as early as 1267, and penalties against it were in force in 1581, 1604, 1836, 1851. In 1822, Accum published a work having the sensational title of ‘Death in the Pot,’ and in 1855 appeared Dr Hassall’s book, ‘Food and its Adulterations.’ The information conveyed in these works, added to the revelations of the ‘Lancet’ Sanitary Commission, and the contributions to scientific literature on the subject of food by Letheby, Pavy, Parkes, Blyth, and others, together with the published evidence given before the House of Commons Commission appointed to carry out an inquiry into the subject, roused public attention to such a degree as to lead to the passing by the legislature of the Adulteration Acts.

1. To give weight or volume, such as water added to butter, plaster of paris to flour, &c.; red earths to annatto, sand to tea-leaves, &c.; water to milk, &c.; all these, therefore, are substitutions of worthless or very cheap articles which take the place of the real.

2. To give a colour which either makes the article more pleasing to the eye, or else disguises an inferior one, e.g., Prussian blue, black lead, &c., to green teas; annatto to cheese, &c.; arsenite of copper to sweetmeats, &c.

3. Substitutions of a cheaper form of the article, or the same substance from which the strength has been extracted put in the place of the real, e.g., tea mixed with spent leaves, &c.

4. A very small class where the adulteration is really added with no fraudulent intent, but to enhance the quality of the goods sold—alum to bread in small quantities.

The following, according to Blyth (‘Dic. of Hygiène’), is a list of articles most commonly adulterated, with the names of the substances used in their sophistication:—

Ale, common salt, Cocculus indicus, grains of paradise, quassia, and other bitters, sulphate of iron, alum, &c.

Anchovies, other fish, and colouring matters, e.g., Armenian bole, Venetian red, &c.

Annatto, all sorts of starch, soap, red ferruginous earths, carbonate and sulphate of lime, salts, &c.

Bismuth, carbonate of lead, sometimes arsenic (this latter is an impurity not intentional).

Cajuput Oil, copper, camphor dissolved in oil of rosemary, and coloured with copper as a substitute.

Calomel, sulphate of baryta, chalk, white precipitate, white lead, pipe-clay, &c., &c.

Champagne, gooseberry and other wines as substitutes, different colouring matters, &c.

Chicory, colouring matters, such as ferruginous earths, and burnt sugar, Venetian red, &c., and different flours, such as wheat, rye, beans, &c., and sometimes sawdust.

Cigars, substitutions of hay and other rubbish, inferior tobacco, leaves sometimes darkened by some brown vegetable dye.

Cocoa and Chocolate, cheaper kinds of arrow-root, such as Tous les mois and East Indian, animal matter, corn, sago, tapioca, &c.

Coffee, chicory, roasted wheat, rye flowers, and colouring matters, such as burnt sugar, &c.

Colocynth (Compound Extract of), the extract is not unfrequently made with the pulp and seeds.

Confectionery, injurious colouring matters, such as arsenite of copper, chromate of lead, &c.

Confection, Aromatic (Aromatic Chalk Powder), expensive ingredients omitted, turmeric substituted for saffron, &c., &c.

Cusparia Bark, the bark of Strychnos Nux Vomica is said to have been substituted.

Flour, other and inferior flours, as the flour from rice, bean, Indian corn, potato, &c., sulphate of lime, alum.

Gin, water, sugar, capsicum, flavouring matters of different kinds, turpentine, alum, tartar.

Iodide of Potassium, water, carbonate of potash, chlorides of soda and potash, iodate of potash, iodine, &c.

Ipecaquanha, other roots, extraneous woody fibre; when in powder, chalk, flour, &c., have been added.

Lemon Juice, a mixture of sugar and water, acidulated with sulphuric acid, has been substituted.

Mercury Ammoniated (WHITE PRECIPITATE), chalk, carbonate of lead, plaster of Paris, &c., 40&c.

Quinine, sulphate of lime, chalk, magnesia, cane-sugar, sulphate of cinchonine, &c.

Tea, sand, iron filings, exhausted tea leaves, foreign leaves; and in green teas, black lead, Prussian blue, China clay.

Wines, water, jerupiga, bitartrate of potash, substitution of inferior wines, brandy, spirits, and various other matters.

“The Sale of Food and Drugs Act” has now supplemented several Acts which were passed during the present century for the prevention of adulteration. An Act prohibiting the mixture of injurious ingredients with intoxicating liquors remains unrepealed, as do also one or two statutes relating to trade frauds as for example the Adulteration of Seeds Act, 1809. These latter have not been incorporated in “the Sale of Food and Drugs” Act.

Æ (ē). [L.] For words sometimes written with this initial diphthong, and not found below, look under E.

ÆGYPTI′ACUM† (-jĭp-tī′-). [Lat.] Syn. Unguen′tum Ægyptiacum, L. Oxymel or liniment of verdigris. The name originated with Hippocrates, who is said to have learned its composition in Egypt.

ÆOL′IPILE (-pĭle). A hollow ball of metal, having a slender neck with a very small orifice, contrived to exhibit the conversion of water into steam by the action of heat, and to account for the natural production of winds. It was known to the ancients, is mentioned by Vitruvius, and was studied by Descartes and others. It has been used in surgery to produce eschars, in the same cases as moxas; the effect of the steam being limited by means of a piece of perforated pasteboard. When filled with alcohol, and the jet of vapour inflamed, it is sometimes employed as a blowpipe. M. Soyer used an apparatus of this kind to supply the heat in his portable furnace. The liquid, however, which he employed was camphine.

A′ERATED (ā′-ĕr-rāte-ĕd). In chemistry, &c., impregnated with carbonic acid. See Alkali, Lemonade, Waters, Mineral.

AE′′RIAL (ā-ēre′-e-ăl). Belonging to the air or atmosphere; produced by, consisting of, depending on, or partaking of the nature of the air.

AERIFICA′TION (ā-ĕr-e-). Syn. Aërifica′tio, L.; Aérification, Gazéification, Fr. In chemistry, the conversion of a body into gas.

A′ERIFORM (ā′-ĕr-). Syn. Aëriform′is, L.; Aériforme, Gazéiforme, Fr. Luftformig, &c., Ger. In chemistry, air-like, gaseous.

AEROL′OGY. Syn. Aërolo′gia, L.; Aérologie, Fr., Ger. In physics, a discourse or treatise of the air. In physiology and hygiène, the doctrine of the air, more especially with regard to its salubrity and action on organised beings.

AEROM′ETER. Syn. Aërome′trum, L.; Aéromètre, Fr. An instrument used in aërometry.

AEROM′ETRY. Syn. Aërome′tria, L.; Aérométrie, Fr.; Luftmesskunst, &c., Ger.41 In chemistry and physics, the art of measuring gases, and of determining their densities.

AERONAUT′ICS. Syn. Aéronautique, Fr. The art of sailing in, or of navigating the air. See Balloons.

AEROPHO′BIA. [L.] Syn. Aérophobie, Fr. In pathology, a dread of air (wind); a common symptom in hydrophobia, and occasionally present in hysteria and phrenitis.

AEROSTAT′ICS. Syn. Aérostat′ica, L.; Aérostatique, Fr. That branch of pneumatics which treats of air, and other elastic fluids, in a state of rest.

AEROSTA′TION. [Eng., Fr.] Syn. Aërosta′tio, L. The art of weighing the air; aërial suspension and navigation. See Balloons.

ÆSCULIN. C₂₁H₂₄O₁₃. A crystalline fluorescent substance existing in the bark of the horse-chestnut (æsculus hippocastanum) and of other trees of the genera Æsculus and Paria. In the above-named sources Æsculin is associated with another fluorescent body called Pariin.

ÆSTHET′ICS (ēz-). Syn. Æsthet′ica, L. Medicines or agents which affect sensation. See Anæsthetics and Hyperæsthetics.

AFFEC′TION. [Eng., Fr.] Syn. Affec′tio, L. In pathology, a term nearly synonymous with disease.

AFFINITY. Syn. Chemical affinity; Affinitas, L.; Affinité, Fr.; Verwandtschaft, Ger. If oil and water be shaken together they produce no change upon one another, as is proved by their separating into two layers with their properties unaltered, when the mixture is allowed to remain at rest for a short time. Such bodies are said, in chemical language, to have no affinity for one another. If iodine and metallic mercury be rubbed together in a mortar they will unite in definite proportions by weight, and form a combination possessing properties totally distinct from those of its constituents. Thus, iodine is a greyish, metallic-looking solid, convertible into a violet vapour by heat, perceptibly soluble in water, and capable of producing a blue compound with starch. Mercury is a metallic, silvery-looking liquid. The product of their union (biniodide of mercury) is a scarlet powder, destitute of metallic lustre, convertible into vapour by heat, without the production of violet fumes, insoluble in water, and incapable of developing a blue colour with starch. Again, the greenish-yellow and intensely poisonous gas, chlorine, unites in definite proportions by weight with the soft, wax-like, and highly poisonous metal sodium to produce the white crystalline solid chloride of sodium (common salt), a compound which, except in very large quantities, is not only not poisonous, but actually beneficial to health.

Such combinations are called chemical compounds, and the force which binds their constituents together is distinguished from all other attractive forces by the term affinity or chemical affinity. Bodies united by affinity are also said to have united chemically.

Affinity is in most cases exerted between different substances, in which respect it resembles adhesion; but bodies united by adhesion, e.g. ink to paper, paint to wood, &c., unlike those united by affinity, suffer no change of properties.

Affinity is exerted at immeasurable distances, therefore substances to be submitted to its influence must be brought into (apparently) actual contact. This condition is frequently fulfilled by the vaporisation, fusion, or solution of one or more of the bodies to be submitted to its action.

In many instances substances which have no affinity for one another at ordinary temperatures manifest this power when heated.

Whenever chemical union takes place, heat is invariably evolved; conversely, the decomposition of a chemical compound is always accompanied by an apparent loss of heat or reduction of temperature.

Finally, the most striking phenomena characteristic of, and accompanying, chemical affinity are, development of heat, change of properties, and union in definite or constant proportions by weight.

AFFUSION. In chemistry, the washing of a precipitate, &c., for the purpose of removing soluble matters. In medicine, affusion is of three kinds:—

1. Lotions, which consist in washing a part of the body with a sponge or rag soaked in a liquid.

2. Aspersions, which consist in throwing a liquid drop by drop, like rain, upon the body.

3. Shower baths, which consist in allowing a number of small streams of water to fall from a height upon the surface of the body. If the water fall from a considerable height, affusion is then termed douche by the French.

AFT′ER-DAMP. Syn. Choke-damp. Carbonic acid gas resulting from explosion of air and fire-damp (light carbonetted hydrogen) in coal mines.

AFT′ER-PAINS. Those following childbirth. The only remedy is patience; they may, however, be frequently alleviated by small doses of morphia or liquor opii sedativus. Heated cloths and warm fomentations are sometimes useful, particularly if assisted by moderate but sufficient pressure on the abdomen, by means of a broad bandage. They seldom follow with severity the first birth.

Treatment for Animals. Remove clots from parts, raise the hind-quarters. Give clysters of linseed tea, lukewarm, and laudanum or42 belladonna extract. Syringe out parts with Condy’s fluid considerably diluted. Give internally belladonna, opium, or chloroform. Draw away milk.

AFT′ER-WASH (wŏsh). In the art of the distiller, the liquor in the still after the spirit has been drawn over.

AG′ARIC. [Eng., Fr.] Syn. Agar′icum, Agar′icus, L.; Blätterschwamm, Pilz, Schwamm, Ger. In botany, a genus of fungi, of numerous species, embracing the mushrooms and champignons. Of these plants, some are edible; others poisonous. The term is also commonly applied to the boletus found on oaks (TOUCHWOOD), and on larches (MALE AGARIC). See Mushrooms.

Fly-agaric. Syn. Fly mush′room; Agar′icus musca′′ria, Linn.; Amani′ta m. One of the most narcotic and poisonous of our fungi, producing, in small doses, intoxication and a pleasing species of delirium; for which purpose it is commonly employed in Kamschatka. (Hooker.) It possesses the singular property of imparting an intoxicating quality to the urine, which continues for a long time after taking it. This secretion is, therefore, commonly saved by the natives during a scarcity of the fungus. “Thus, with a few amanitæ, a party of drunkards may keep up their debauch for a week;” and the intoxication so produced is capable of “being propagated through five or six individuals.” (Langsdorff.) Water in which it has been boiled is poisonous; but the boiled fungus itself is inert. The liquid from it is used as a fly-poison; whence the name mushroom is derived. It may be known by its rich orange-red colour in autumn.

AG′ATE (-āte, -ĕt‡). [Eng., Fr.] Syn. Acha′tes (-kā′-tēz), L. A semi-pellucid uncrystallised species of quartz, remarkable for its hardness, variety of colour, and susceptibility of receiving a high polish. It is an aggregate of various siliceous minerals, of which chalcedony appears generally to be the base. Carnelian, jasper, amethyst, and other similar minerals, often enter into its composition. The colours are often delicately arranged in stripes, bands, or clouds. Those which take an angular form, as the Scotch pebble, are called FORTIFICATION AGATES. It is the least valuable of the precious stones, and is chiefly made into rings, seals, beads, burnishers, &c., on account of its hardness. Its powder is used for cleansing and polishing iron, brass, &c., and to sharpen edge-tools.

AGEING LIQUOR. Dissolve 3 lbs. of chlorate of potash in 4 galls. of boiling water. Add 20 lbs. of powdered white arsenic to 20 lbs. of solution of caustic soda at 60° Tw., and boil until the arsenic is completely dissolved. Add the latter solution to the former, with stirring, until the mixture stands at 28° Tw.

AGRYPNOT′ICS (-grĭp-). Syn. Anthypnot′ics (-hĭp-); Agrypnot′ica, Anthypnot′ica, L. In medicine and pharmacology, agents or substances which prevent sleep; as tea, coffee, digitalis, vinegar, &c.

A′GUE (-gŭ). Ague may be defined as febrile phenomena occurring in paroxysms, and observing a certain regular succession, characterised by chill, abnormal heat, and unnatural cutaneous discharge, which prove to be a temporary crisis and usher in a remission. These phenomena are developed in an uninterrupted series or succession more or less regular, which pass into each other by insensible stages. Ague is paludal fever, and has always been observed to prevail in marshy moist districts, and in low, swampy humid countries, in which seasons of considerable heat occur.

The neighbourhood of marshes, or of a district which has been at some recent time under water; the banks of extensive lakes, and the shores of rivers and seas where the water flows sluggishly, and in some places stagnates; shallow rivers; extensive level tracts of forest land, where moisture is always present; and the surface of the land constantly covered with excavation from the ground,—these are the terrestrial physical conditions, in which marsh and littoral fevers are almost universally to be found, although it must be admitted that there are some marshy districts in which the disease does not show itself.

In these latter localities the effects of the miasmatic poison, show themselves in cholera or typhus. No precise knowledge of the nature and source of this subtle poison which, in default of a better name we call malaria, has yet been acquired; indeed it has yet to be proved that malaria has a distinct existence. Science has as yet been unable to discover the presence of any poisonous principle in the air of ague on other regions.

Ague may exist without any alteration of structure being set up; but in the milder forms of this fever a greater number of organs and tissues are morbidly altered than perhaps in any other form of disease. The parts so affected are the liver, spleen, lungs, heart, brain, and the serous and mucous membranes of the body generally. Within certain limits, the specific action of the malarial poison may be said to be in the inverse ratio of the intensity of the fever which attends its action. The affections of the liver and spleen also vary greatly according to the locality in which the patient is attacked; for instance, whilst in some parts of India the spleen is the organ principally involved, in other districts of the same continent it is the liver. In England, under proper medical treatment, the patient usually recovers without any manifest derangement either of structure or impairment of function of any organ or tissue. The liver may, however, become affected if the patient suffering from the disease has been neglected for any length of time.43

Notwithstanding the opinions of Finke and Professor Colin, there appears to be considerable ground for the supposition that ague may be caused by drinking marsh and surface water. In an interesting paper on the ‘Indian Annals’ for 1856, Mr Bettington, of the Madras Civil Service, says:—“It is notorious that the water produces fever and affections of the spleen.” In confirmation of this assertion, he brings forward what seems to be some remarkably strong evidence. He cites cases of villages placed under the same conditions as to marsh-air in some of which fevers were prevalent, whilst in others they were absent; and he found on inquiry that whilst the latter villages were supplied with pure water, the inhabitants of the former had to drink marsh or mullah water, full of vegetable débris. In one village there were two sources of supply—a spring and a tank, the first fed by surface, and the other by marsh water. Those only who partook of the tank water were attacked by fever. Again, in Tulliwaree the fever was so universal that scarcely any inhabitant escaped it. In this village Mr Bettington caused a well to be dug, and the result was that the fever disappeared. Similar cases have occurred in this country. Twenty years ago Mr Blower, of Bedford, directed the attention of medical men to a case that occurred in a village, in which ague had nearly disappeared when a well was dug; and to another instance which occurred in the village of Houghton. In this parish almost the only family which escaped ague was that of a farmer; the members of this family partook of well water; whilst those who did not escape the disease drank ditch water.

In the ‘Indian Annals’ for 1867 is a paper by Dr Moore, confirming the opinion that ague may be produced by the causes already stated, and M. Commaille (‘Rec. de Mêm. de Med. Mil.,’ Nov., 1868) states that in Marseilles, paroxysmal fevers, formerly unknown, have made their appearance, since the water supply to that city has been drawn from the Marseilles Canal.

In his report for 1870 Dr Townsend, the Sanitary Commissioner for the central provinces of India, states that the natives of India hold an opinion that the use of river and tank water during rainy seasons (when the water always contains an increased quantity of vegetable matter) will almost always cause ague. Boudin (‘Traité de Géographie et de Statistiques Médicale,’ 1857, t. i, p. 142), records an extraordinary case. Eight hundred soldiers, in good health, embarked in three vessels to pass from Bona, in Algiers, to Marseilles, in the year 1834. They all arrived at Marseilles the same day. In two vessels there were 680 men, without a single sick one amongst them. In the third vessel, the Argo, there had been 120 soldiers; 13 died during the short passage, and of the 107 survivors no less than 98 were disembarked suffering from all forms of paludal fevers. We may presume that the diagnosis was correct, since Boudin himself examined the men. When the vessels started the crew of the Argo had not a single sick man aboard. The crew and soldiers of all the boats were exposed to the same atmospheric conditions. The influence of air must, therefore, be excluded. There is no mention of food, but it has never been suggested that food has ever been concerned in the production of malarious fever. It was a very different matter, however, with the water supply. In two of the vessels the water was good, whilst the Argo had been supplied with marsh water, which was offensive to the smell, as well as unpalatable. This latter was supplied to the soldiers, whilst the crew drank uncontaminated water. Amongst those who deny that marsh water is the cause of ague must be quoted Professor Colin. The professor, who is regarded as an authority on intermittent fever, in his work De l’Ingestion des Eaux Marécageuse comme cause de la Dysenterie et des Fièvres intermittentes,’ instances numerous cases in Algiers and Italy in which impure marsh water gives rise to indigestion, diarrhœa, and dysentery, but in no case to intermittent fever; and he states that in all his observations he has never met with an instance of ague having such an origin. Without contesting the case of the Argo, he views it with considerable suspicion, and doubts whether Boudin is correct in his details. Finke also states that, in Hungary and Holland, marsh-water is daily drank without causing any ill-effects. The inhalation of the fumes of oxide of zinc appears to produce in workers of this metal a variety of ague termed by Shackrah “brass ague,” and by Dr Greenhow, “brass-founder’s ague.” The symptoms of the malady are tightness and oppression of the chest; with indefinite nervous sensations, followed by shivering, an indistinct hot stage, and profuse perspiration. These attacks, however, are not periodical.

It is open to doubt whether the malarious poison exists in the form of a gas, for the observations of microscopists go to show the extreme minuteness of the germs of disease, which are probably not more than ¹⁄₇₀₀₀₀th of an inch in size, and it is regarded as probable that the real cause of ague is the entry into the circulation of some low forms of spores of fungi, or of some minute animalcules. Ague is always to be met with in places where fungi grow, and is always associated with what Pettenkofer calls “the ground air”—that is, the air contained in the interstices of the soil, no inconsiderable volume of which is drawn into every house which has a fire on the floor which rests on the earth. That animalcules (?) may exist in the blood is evidenced by the discovery of Dr Lewis, who found hair-like worms in the circulation; and whilst considering this point, we must bear in mind that the44 remedial agents employed to check ague, quinine, arsenic, &c., are drugs capable of destroying animal life, and it is not impossible that they may exercise a beneficial effect in destroying the spores or animalcules to which the disease may be due.

The best means to be employed to combat malarial fevers in any district are thorough and efficient drainage (and it must be remembered that drainage purifies both the ground-air and the ground water) and a supply of wholesome water free from decomposing vegetable matter.

That the adoption of the above means cannot fail to succeed is incontestably proved by the fact, that during the last 200 years, ague in England has diminished to a wonderful extent, in short, as good drainage and a pure water supply have prevailed, there has been a proportionate diminution of paludal poisoning.

During the protectorate of Cromwell great mortality prevailed in London, from the ravages of ague; at that time London was as swampy as the fens of Lincolnshire. See Fever (Intermittent).

Ague-cake. The popular name of a tumour felt under the false ribs on the left side, formed by enlargement and induration of the spleen, following protracted ague; also, sometimes, of indurations of the liver following ague.

Ague-weed. The herb thorough-wort (‘Eupato′′rium perfolia′tum,’ Linn.).

AIG′REMORE (ĕg′r-mor). [Fr.] Pulverised charcoal in the state it is used to make gunpowder.

AIGUILLETTE (Attelette). [Fr.] In cookery, a term applied to several small dishes, from the articles of which they consist being mounted on silver needles, or skewers, with ornamental handles or tops. (See engr.) They form one of the varieties of the ‘hors-d’œuvres’ of Soyer; and are commonly served on a napkin. The skewers should be about four inches long, and of the thickness of an ordinary packing needle. The person eating what is served on them takes the head of the skewer between the thumb and fingers of the left hand, and picks it off with his fork. Those noticed by Soyer are—

all of which are prepared in a nearly similar manner, merely varying the sauces, &c., to suit the article and palate. See Attelettes, Hors-d’œuvres, &c.

AHORNZUCKER (genuine American maple sugar). For coughs, hoarseness, and all affections of the throat and chest caused by cold. The raw maple sugar as imported. (Hager.)

AILANTHUS. The inner bark of the ailanthus glandulosa, a common tree growing in northern China, said by Dr Dudgeon to have proved very successful in dysentery.

The ailanthus glandulosa is also well known throughout the United States. Professor Hétet, of Toulon, tried the effect of the powdered bark, leaves, and various preparations of the bark or drugs, with the result of their administration being attended with purgative effect—and the discharge of worms.

The powdered bark has been given in small cases of tape-worm in the human subject, with marked success. The dose of the powder found sufficient for the expulsion of the tapeworm was from seven or eight to thirty grains.

AIL′MENT. Pain, indisposition; disease. Its use is generally restricted to the non-acute, and milder forms of disease.

AIR. [Eng., Fr.] Syn. Aer, L. (from αηρ Gr.); Luft, Ger.; Atmospheric Air; The Atmosphere. This name was formerly given to any aëriform body; thus, by the old chemists ammoniacal gas was called alkaline air; oxygen,—dephlogisticated, vital, or empyreal air; carbonic anhydride (carbonic acid), fixed air; hydrogen, inflammable air; heavy carbonetted hydrogen, olefiant gas, heavy inflammable air; nitrogen,—mephitic, phlogisticated, or nitrous air. At the present time the term air is usually restricted to the gaseous envelope surrounding the solid and liquid parts of our globe.

Air, Atmospheric (or simply, The Air). The air chiefly consists of a mechanical mixture of four volumes of nitrogen and one volume of oxygen, or more accurately—

	By volume.	By weight.
Nitrogen	79·1	76·8
Oxygen	20·9	23·2
	———	———
	100	100 [12]

We may premise our description of the functions of the constituents of the atmosphere by the following quotation from Mr Blyth’s ‘Dictionary of Hygiène and Public Health’:—“One of the most important properties of air is its power of penetration and its universality. Air is, indeed, present everywhere; there is scarcely a solid, however compact it may appear to be, which does not contain pores, and these pores filled with air. The soil contains no small quantity; indeed, if it were not so the numberless insects, worms, &c., which burrow in its interstices would cease to exist. The most compact mortar and walls are penetrated with it, and water of natural origin contains a large quantity of air in solution. The atmosphere is supposed to extend to a very great height, from 200 to 300 miles; it used to be considered only five (forty-five) miles high, but observations on shooting stars, &c., show that this opinion is erroneous. Owing to the force of gravity, the air is much denser near the earth, and gets more attenuated layer by layer as you ascend. If, then, the atmosphere were possessed of colour, it would be very dark just round the globe, and the tint would gradually fade into space. The air is by no means wholly gaseous; it contains, indeed, an immense amount of life, and small particles derived from the whole creation. In the air may be found animalcules, spores, seeds, pollen cells of all kind, vibriones, elements of contagion, eggs of insects, &c., and a few fungi, besides formless dust, sandy, and other particles of local origin; for example, no one can ride in a railway carriage without being accompanied with dust, a great portion of which is attracted by a magnet, and is, indeed, minute particles of iron derived from the rails. The purest air has some dust in it. There probably never fell a beam of light from the sun since the world was made which did not show, were there eyes to see it, myriads of motes; these, however, generally speaking, are quite innocuous to man—some, indeed, may possibly be beneficial. Another most important property of air is its mobility; on the calmest day and in the quietest room there are constant currents of air which rapidly dilute any noxious odours of gases.”

The chief functions of the oxygen are to maintain respiration and support combustion, while the office of the nitrogen is to dilute the oxygen and control its energy.

Besides nitrogen and oxygen, aqueous vapour, carbonic anhydride, ammonia, and nitric acid are met with in the atmosphere, the last especially during and shortly after thunder storms.

Although, doubtless owing to local conditions, trifling variations may occur in the proportion of oxygen present in the atmosphere, this variation is so trifling that the difference of the amount in air from places separated by very long distances will be found in the second decimal place only; thus, whilst a portion of air taken during a balloon ascent by Mr Green gave on analysis 20·88 per cent. by vol., Dr Frankland found in air collected by himself on the summit of Mont Blanc 20·96 per cent. by vol. A still nearer approximation in uniformity in the amount of oxygen present in atmospheric air is exhibited in the following table, which gives the results of 95 analyses by Regnault on air obtained from nine different localities:—

100	from Paris gave in 100 parts, by vol. of oxygen	20·913 to	20·999
9	from Lyons and around gave in 100 parts, by vol. of oxygen	20·918 to	20·966
30	from Berlin gave in 100 parts, by vol. of oxygen	20·908 to	20·998
10	from Madrid gave in 100 parts, by vol. of oxygen	20·916 to	20·982
23	from Geneva and Switzerland gave in 100 parts, by vol. of oxygen	20·909 to	20·993
15	from Toulon and Mediterranean gave in 100 parts, by vol. of oxygen	20·912 to	20·982
5	from Atlantic Ocean gave in 100 parts, by vol. of oxygen	20·918 to	20·965
1	from Ecuador gave in 100 parts, by vol. of oxygen	20·960
2	from Pichincha gave in 100 parts, by vol. of oxygen	20·949 to	20·981
		———	———
	Mean of all foregoing	20·949	20·988
	Mean of the Paris specimens	20·96

Vapour of water is essential to the respiration of animals and plants, in order that the organs concerned in this operation may be kept in a soft and moist condition.

Carbonic anhydride is evolved during combustion, putrefaction, and fermentation; it is also a product of the respiration of animals, and highly poisonous to them, even when diluted with large proportions of air. This gas is, however, greedily absorbed by plants, which decompose it; they assimilate the carbon and return the oxygen to the atmosphere, ready to be again consumed in supporting the life of the animal world.

Dr Angus Smith has defined a very pure air to be one that contains with 20·99 per cent. of oxygen 0·30 of carbonic acid (anhydride).

This latter varies in amount in the atmosphere of cities, as will be seen upon inspection of the subjoined table, extracted from Dr Smith’s work ‘Air and Rain’:46—

	Per cent.
Air of Madrid, outside the walls, mean of 12 analyses, by Luna	·045
Mean of 12 analyses, within the walls of Madrid, by Luna	·051
Mean of 14 analyses, by Angus Smith, in Manchester suburbs	·369
In Manchester streets	·403
Usual weather	·0403
During fogs	·0679

De Saussure’s analyses show that there is more carbonic acid on the mountains than in the plains, as might be inferred from the comparative absence of vegetation in elevated positions. Dr Pietra Santa states that the air of hills or mountains, at the height of 2300 feet, is lighter than common air, contains a smaller proportion of oxygen, and is impregnated with a largely increased amount of aqueous vapour. It also contains a large quantity of ozone. He considers such a climate peculiarly soothing to persons suffering from chest diseases.

Dr Angus Smith’s analysis of the air from the mountainous districts of Scotland confirms the above statement of Dr Pietra Santa’s. The heaths and mountains of that country are remarkably healthy localities, and the air from them gave on analysis 20·94 per cent. by vol. of oxygen, and only ·033 of carbonic acid.

Ammonia is derived from the putrefaction of animal and vegetable substances. It is from atmospheric ammoniacal compounds that plants obtain much of the nitrogen which is essential to the formation of many parts of their structure.

Nitric acid, like ammonia, is absorbed, and its nitrogen assimilated, by plants.

In addition to the gases and vapours already enumerated, as well as others which exist in minute quantity, or which are of only occasional occurrence, Pasteur and other investigators have discovered in the air living germs which are capable of exciting putrefaction and fermentation, and which are competent, in some instances, to engender disease when they are injected into the blood of animals. In fact, the spread of infectious diseases, e.g., smallpox, typhus fever, cattle plague, &c., is attributed to the presence in the atmosphere of the germs of such maladies. These germs are believed to be living beings, which develope and multiply at the expense of the tissues of the larger animals into whose systems they have found entrance.

Air, Vitiated. As has been stated in the previous article, the air consists chiefly of two gases, oxygen and nitrogen. In all open places it has a similar composition, as might be concluded from the constant mingling which takes place by the agency of currents continually in movement, although sometimes to an inconsiderable extent only. Dr Angus Smith regards air as very pure when it contains not less than 20·99 per cent. by volume of oxygen, and 0·030 of carbonic anhydride (acid). According as the proportion of the former gas diminishes and that of the latter increases beyond certain limits in the air by which we are surrounded, it becomes more or less deteriorated and unfit to be breathed, particularly as the increased amount of carbonic acid is, in crowded dwellings, assembly rooms, theatres, and confined inhabited spaces, associated with deleterious and putrescent exhalations from the person.

	Per-centage
	by volume.
Chancery Court, closed doors, 7 feet from the ground, March 3	·193
Same, 3 feet from ground	·203
Chancery Court, doors wide open, 4 feet from ground, 11·40, March 5	·0507
Same, 12·40 p.m., 5 feet from ground	·045
Strand Theatre, gallery, 10 p.m.	·101
Surrey Theatre, boxes, March 7, 10·30 p.m.	·218
Olympic, 11·30 p.m.	·0817
Same, 11·55 p.m.	·1014
Victoria Theatre, boxes, March 24, 10 p.m.	·126
Haymarket Theatre, dress circle, March 18, 11·30 p.m.	·0757
Queen’s Ward, St. Thomas’s Hospital, 3·25 p.m.	·052
Edward’s Ward, St. Thomas’s Hospital, 3·30 p.m.	·052
Victoria Theatre, boxes, April 4.	·076
Effingham, 10·30 p.m., April 9, Whitechapel	·126
Pavilion, 10·11 p.m., April 9, Whitechapel	·152
City of London Theatre, pit, 11·15 p.m., April 16	·252
Standard Theatre, pit, 11 p.m., April 16	·320

Dr Angus Smith states that out of 339 specimens of air obtained from various mines he found 35 normal or nearly so, 81 decidedly impure, and 212 exceedingly bad; he also adds that owing to the frequent firing of charges of gunpowder within the mines, and from other causes, the atmosphere is further contaminated with sulphuretted hydrogen, sulphate, carbonate, sulphide, sulphocyanide of potassium, and nitrate of potassium, carbon, sulphur, carbonate of ammonia, organic matter, sand, and sulphurous and arsenious acids.

The air of large cities, which are the seats of manufacturing industry, is always more or less charged with the exhalations given off by chemical and other works. The sulphuric-acid works contribute sulphuric, sulphurous, nitrous, and arsenious acids; copper works, in which pyrites is employed, give off large quantities47 of sulphurous acid, mixed with arsenic and a little copper; manure works, in many cases, send out compounds of fluorine, besides sulphuric acid; glass works, sulphuric and hydrochloric acids; and alkali works, hydrochloric acid (although in small quantities), which very frequently contains arsenic. Of ammonia, Angus Smith remarks: “It is one measure of the ‘sewage’ of the air; it is the result of decomposition. It is not, in these small quantities, hurtful, so far as we know. The ammonia is in no case free, but combined probably with hydrosulphuric, hydrochloric, and sulphuric acid in towns. In country places it is, at all events partly, united to carbonic acid.

Date.	Place.		Time of Day.	Carbonic Acid, per cent.	Oxygen, per cent.
1869. Nov.	12.	Tunnel between Gower Street and King’s Cross Stations; specimen taken at the open window, first-class carriage.	10 a.m.	·150	20·60
”	12.	Tunnel between Gower Street and King’s Cross Stations; specimen taken at the open window, first-class carriage.	7·30 p.m.	·078	20·79
”	12.	Tunnel Praed Street; specimen taken at the open window, first-class carriage.	10·30 a.m.	...	20·71
”	15.	Specimen taken during journey between Gower Street and King’s Cross, first-class carriage, window open.	10·15 a.m.	·338	20·66
”	15.	Same	3 p.m.	·155	20·70
”	15.	Same	11 p.m.	·150	20·74
			Average	·1452	20·70

Name of Mine, and depth from surface, in fathoms.	Description of place, where taken and time when taken.	Thermometer, Fahr.	Number of Men working in it.	Oxygen, per cent.	Carbonic Acid, per cent.
Hurst	End, 300 ft. beyond a rise, 9 ft. high, 7 ft. wide.	...	2	...	1·99
Old Gang	End of level	...	2	20·58	·48
”	End of level	...	2	...	·28
”	(a) Rise 7 ft. high, 132 ft. from current.	...	2	20·25	·39
Grassington	(b) End of cross cut, 480 ft. from rise.	...	2	20·94	·06
”	End, 480 ft. from rise.	...	2	19·53	1·59
”	Rise 60 ft. high in shale.	...	2	19·52	1·72
”	End, 60 ft. from rise.	...	2	20·47	1·06
”	(c)End, 840 ft. from rise.	...	2	20·08	·94

(a) Air machine.
(b) Unusual amount of dust.
(c) Crystals were chiefly hexagons.

The following table, showing the amount of ammonia present in rain collected at the different places named, is from Dr Smith’s work, ‘Air and Rain.’

Comparative.	Ammonia.
That of Valentia (Ireland) taken as 1 or 100.
Ireland, Valentia	·1
Scotland, sea-coast, country places, west	2·69
Scotland, inland, country places, west	2·96
Scotland, sea-coast, country places, average	4·10
Scotland, sea-coast, country places, east	5·51
England, inland, country places, east	5·94
England, sea-coast, country places, west	10·55
German specimens	10·61
London, 1869	19·17
Scotland, towns (Glasgow not included)	21·22
St. Helen’s	25·33
Runcorn	25·72
England, towns	28·67
Liverpool	29·89
Manchester, 1869	35·33
Manchester, 1869 and 1870, average	35·94
Manchester, 1870	36·54
Glasgow	50·55

The effects resulting from breathing an impure atmosphere are necessarily dependent upon the extent of the pollution and other conditions. When the contamination is moderate the first effect is headache, accompanied with lassitude, and a general paleness of the face and skin, owing to a diminution of the red corpuscles of the blood or to their imperfect aëration; the pulse becomes lowered, and at the same time the breathing is accelerated. When in addition to breathing such air from day to day is superadded the misfortune of an insufficiency of food, scrofula and consumption very often follow. Dr Guy has demonstrated the great mortality that is caused by consumption in those trades in which workmen pursue their calling in hot, close, gas-lit rooms, in comparison with those who pass most of their time in the open air. The amount of air required by each person in a room is no less than 2100 feet per hour; when the ventilation does not supply this amount of fresh air, the apartment smells stuffy, the furniture becomes coated with a film of organic matter, unless constantly cleaned, and the carbonic acid becomes increased beyond its normal quantity.

Dr Parkes has shown that bronchitis and consumption are more frequently than not contracted by those who live in an atmosphere of foul air. In the years 1834 to 1847 the proportion of deaths in the ill-ventilated prison of Leopoldstadt in Vienna was 86 per 1000, out of which number 51·4 per 1000 was due to phthisis or consumption; while in the well-ventilated House of Correction in the same city the deaths were 14 per 1000, of which 7·9 were from phthisis; hence 43·5 cases per 1000 of the deaths were clearly traceable to foul air and nothing else.

Mr Noel Hartley, in his valuable little manual, ‘Water, Air, and Disinfectants,’ says: “During the outbreak of cattle plague in 1866, in sheds containing twenty to thirty cows—which the owners kept closed to such an extent that all chinks in the doors and windows were stuffed with straw and matting, under an ignorant belief that thus the plague could be kept out—very frequently the entire stock died in two or three days after the first appearance of disease; while in other cases where animals were housed in a well-cleaned and tidily-kept shed, with a plentiful supply of fresh air, not only did some of them escape the disease altogether, but the deaths were reduced to one third of the number of beasts attacked.”

The large supply of fresh air necessary in hospitals for contagious diseases is fully recognised by medical men, and more especially so in America. Wounds carefully protected from contact with impure air do not suppurate, and organic fluids do not putrefy. On the other hand, in a bad atmosphere sores become unhealthy, and are difficult to heal, erysipelas and hospital gangrene frequently set in, while the best prevention and the best means of cure for such afflictions is the greatest possible exposure to fresh air.

Vitiated air, as a consequence of over-crowding, aids the spread of measles, scarlet fever, and the much to be dreaded smallpox; it brings on ophthalmia, a troublesome inflammation of the eyes, and is not unfrequently the cause of the ricketty and scrofulous condition of children. Although exposure to cold does cause such affections as bronchitis, pneumonia, cold in the head, sore throat, and other affections of the respiratory organs, it is more frequently the case that they are the result of a sudden change of temperature, such as experienced in coming out of a crowded assembly in a close, badly-ventilated building, than by actually cold weather. This is decidedly and strikingly shown by the fact which Dr de Chaumont has quoted, that the British Army when in the Crimea, when lodged in tents during extremely rigorous weather, experienced a wonderful condition of health, such a thing as a cold being an unknown complaint; but when some of the men were placed in huts which were much warmer, and into which there was a smaller circulation of fresh air, the sick rate increased, and coughs and colds began to put in an appearance. Persons who during summer and winter sleep with their windows more or less open cannot endure a night spent in the chamber with the chimney closed and the window shut. A less refreshing sleep occupies the night, and a somewhat feverish sensation is felt next morning.

If in cold weather the window be opened only one inch at the top, the difference in the air in the bedroom is something quite beyond comprehension to those who have not paid attention to these things. See Ventilation.

Air, Analysis of. Priestley’s discovery of oxygen gas in 1774 prepared the way for the knowledge of the real composition of air, which was discovered about the same time by Scheele and Lavoisier. Scheele’s method of operating was by exposing some atmospheric air to a solution of sulphide of potassium. Lavoisier effected the same object by the combustion of iron wire and phosphorus, and subsequently by heating mercury on a flask filled with air for some time, just below its boiling point.

These, however, were but elementary methods, which, however creditable to the ingenuity of the great founders of modern chemistry, not only failed in accuracy, but49 took no account of the presence and amount of two most important constituents in the atmosphere, viz. carbonic anhydride (acid) and ammonia.

Determination of Aqueous Vapour. To effect this an aspirator must be used (see Aspirator). This instrument is easily made, and is not expensive. The accompanying figure will illustrate the arrangement generally adopted: a is an aspirator made of galvanised iron or sheet zinc. It holds from 50 to 200 litres (from 11 to 44 gallons). By this means a known volume of air is drawn through the tubes marked b, c, d, e, which may be filled with pumice-stone moistened with strong sulphuric acid; but if the carbonic acid is to be estimated as well, b and c are filled with moist hydrate of lime (potash used to be employed, but hydrate of lime is to be preferred, as the potash absorbs oxygen), and d and e as above. Each of the tubes is accurately weighed previously to connecting them with the apparatus.

It is imperative to have each of the tubes connected by perfectly air-tight joints. The gain of weight in d and e gives the water in b and c the carbonic acid.

Determination of Carbonic Acid. A better and perhaps more exact means of determining the carbonic acid is that invented by Pettenkofer. It may be briefly described as follows:—Baryta water of definite strength is prepared and accurately standardised by a standard solution of oxalic acid. A portion of this baryta water is then made to act upon a definite quantity of air. It will absorb the whole of the carbonic acid in that air.

The alkalinity of the liquid will in consequence be diminished; it will take less of the oxalic-acid solution than before, which shows so much less caustic baryta, and from which the carbonic acid absorbed may be easily calculated.

The actual Analysis. Two kinds of baryta water may be used, the one containing 7 grammes to the litre, the other three times that strength; 1 c. c. of the stronger = 3 m. grms. of carbonic acid; 1 c. c. of the weaker = 1 m. grm. The baryta water is best kept in the bottle represented below.

The bottle (a) contains the baryta water. It has an accurately-fitting double-perforated stoppered caoutchouc. The left-hand tube is connected with the tube (b) containing pumice-stone moistened with potash, while the right-hand one is a syphon. When required for use the stop-cock (f) is opened, and suction applied by a glass tube to F. The syphon is thus filled and the stop-cock closed. If a pipette is required to be filled its nozzle is inserted at F, the stop-cock compressed, and the fluid immediately rises into the pipette.

The air entering the bottle as the fluid decreases in a is, of course, thoroughly deprived of its carbonic acid by the tubes at b.

The first thing to be done is to standardise the baryta solution by a solution of oxalic acid, containing 2·8636 grammes of crystallised oxalic acid to the litre.

Thirty c. c. of baryta solution are run into a small flask, and the oxalic acid run in from a Mohr’s burette with float, the vanishing-point of the alkaline reaction being ascertained by delicate turmeric paper. As soon as a drop placed on turmeric paper does not give a brown ring the end is attained.

The actual analysis is performed by filling a bottle of known capacity, with the aid of a pair of bellows, with the air to be analysed, then distributing over its sides 45 c. c. of the baryta water it is left for half an hour. The turbid water is poured into a cylinder, closely secured, and allowed to deposit; then take out 30 c. c. by a pipette of the clear fluid, run in the solution of oxalic acid, multiply the volume used by 1·5, and deduct the produce from the c. c. of oxalic acid used for 45 c. c. of the fresh baryta water. A different method has been suggested by Dr Angus Smith, viz. to measure the carbonic anhydride by the turbidities of the baryta water; this is, in fact, a colorimetric test. For rough approximative results Dr Smith’s process will be found a very useful and convenient one. It depends upon the fact that the amount of carbonic acid in a given quantity of air will not produce a precipitate in a given quantity of lime or baryta water unless the carbonic acid is in excess. The following is one of his tables:—Columns 1 and 250 give the rates of carbonic acid in the quantity of air which will produce no precipitate in half an ounce of lime water. Column 3 is the same as column 2; but 14·16 c. c. (half an ounce) is added to give the corresponding size of the bottle, and column 4 gives the size of the bottle in ounces.

Carbonic Acid in the Air, per cent.	Volume of Air in cubic centimètres.	Size of bottle in cubic centimètres.	Size of bottle in ounces Avoirdupois.
·03	185	199	7·06
·04	139	154	5·42
·05	111	125	4·44
·06	93	107	3·78
·07	79	93	3·31
·08	70	84	2·96
·09	62	76	2·69
·10	56	70	2·46
·11	51	65	2·29
·12	46	60	2·14
·13	43	57	2·01
·14	40	54	1·90
·15	37	51	1·81
·20	28	42	1·48
·25	22	36	1·29
·30	19	33	1·16
·40	14	28	1·04
·50	11	25	·89
·60	9	23	·89
·70	8	22	·78
·80	6	20	·72
1·00	5·5	19·7	·70

Mr Wanklyn’s process for the determination of carbonic acid in the atmosphere is as follows:—A solution of carbonate of soda is first made as follows: 4·47 grammes of gently-ignited carbonate of soda are dissolved in one litre of water, giving a solution of such a strength that 1 c. c. contains exactly 1 c. c. of carbonic acid (= 1·97 milligrammes of CO₂); a large quantity of baryta water (strength about 0·1 per cent.) is prepared.

If now 100 c. c. of clear baryta water be treated with 1 c. c. of carbonate of soda, just described, a certain degree of turbidity is produced.

If 2 c. c. of the solution be taken another degree of turbidity is produced, and so on. If, then, a bottle capable of holding 2000 c. c. of air, together with 100 c. c. of baryta water, be filled with the sample of air to be tested, there will be a certain depth of turbidity produced by shaking it up. Having got the air to expend itself on 100 c. c. of baryta water the degree is to be found by comparison with another 100 c. c. of baryta water, in which a like turbidity has been induced by means of the standard solution of carbonate.

Every c. c. of soda solution counts for a c. c. of carbonic acid in two litres of air. A consumption of 1 c. c. will correspond to ·05 volumes of carbonic acid per cent. Good air should accordingly not take more than 1 c. c. of soda solution, air which takes already 2 c. c. being already bad.

In order practically to carry out this method of estimating carbonic acid the following apparatus is required:—Several bottles capable of holding 2·210 c. c., and well stoppered (failing bottles of exactly the right capacity Winchester quart bottles will answer); a small pair of bellows; several colourless glass cylinders marked at 100 c. c. capacity—the Nesslerising cylinders will answer for this purpose—a graduated pipette or burette to deliver tenths of a c. c. of solution, the standard solution of carbonate of soda, and the baryta water, which may be of moderate strength.

The testing is managed thus: Winchester quart bottles having been made clean are rinsed with distilled water, and allowed to drain a little. They are then closed with their stoppers, and are ready for use. The operator having provided himself with two or three of these bottles and a small pair of bellows enters the room the air of which is to be tested. The stopper is then removed from one of the bottles, and some air of the room blown through with the bellows, and then the stopper is replaced, and the bottle carried away to be tested.

The testing is done by pouring into the bottle 100 c. c. of clear baryta water, shaking up for two or three minutes, and then pouring out into a cylinder of colourless glass, and observing the depth of the turbidity in various lights and against various backgrounds. The turbidity is to be exactly imitated by means of the standard solution of carbonate of soda. In order to imitate the turbidity produced by a Winchester quart full of good air only 1 c. c. of this solution of carbonate of soda is required.

If 2 c. c. or more than 2 are required, the air is bad and the ventilation is defective.

In place of the first c. c. of solution of carbonate of soda the carbonic acid naturally present in a Winchester quart of good average air may be used, and a little practice and intelligence will suggest the necessary precautions.

Estimation of the Oxygen.—To determine this Angus Smith has recourse to the endiometer. Five or six of Bunsen’s endiometers were used at once and the mixed gases were exploded by means of a powerful battery and a Ruhumkorff’s coil. In his ‘Inorganic Chemistry,’ Miller thus explains the principle upon which the action of the endiometer is based: “By means of the endiometer various gaseous mixtures may be analysed with great exactness. Many different forms of this instrument are in use. One of the most convenient is Hoffmann’s. It consists of a stout syphon tube. (See next figure.) Into the sides of the51 tube, near the sealed end, two platinum wires (a, b) are fixed for the purpose of transmitting an electric spark through the cavity of the tube. The sealed limb is accurately graduated to tenths of a c. c. or other suitable divisions. Suppose it be desired to ascertain the proportion of oxygen in atmospheric air. The instrument is first filled with mercury, after which a small quantity of air is introduced; the bulk of the air is accurately measured, taking care that the liquid metal stands at the same level in both tubes, which is easily effected by adding mercury, or by drawing off the mercury if needed, through the caoutchouc tube, which is fixed upon the small inlet tube just above the bend, and which is closed by means of a screw tap (c).

A quantity of pure hydrogen, about equal in bulk to the air, is next introduced, and the bulk of the mixture is then accurately measured. The open extremity of the tube is now closed with a cork, below which a column of atmospheric air is safely included. This portion of air acts as a spring, which gradually checks the explosive force, when the combination is effected by passing a spark across the tube by means of the platinum wires. The mixture is then exploded by the electric spark. The remaining gas now occupies a smaller volume, owing to the condensation of the steam which has been formed. Mercury is, therefore, again poured in the open limb until it stands at the same level in both tubes, and the volume of the gas is measured a third time. One third of the reduction of the bulk experienced by the gas will represent the entire volume of oxygen which the mixture contained. Liebig’s method is as follows. It is based upon the fact that an alkaline solution of pyrogallic acid absorbs oxygen:

1. A strong measuring tube holding 30 c. c., and divided into one fifth or one tenth c. c., is filled to two thirds with the air intended for analysis. The remaining part of the tube is filled with mercury, and the tube is inverted over that fluid in a tall cylinder widened at the top.

2. The volume of air confined is measured—a quantity of solution of potash of 1·4 sp. grf. (1 part of dry hydrate of potash to 2 parts of water), amounting from ¹⁄₄₀th to ¹⁄₅₀th of the volume of the air, is then introduced into the measuring tube by means of a pipette with the point bent upwards (see drawing), and spread over the entire inner surface of the tube by shaking the latter. When no further diminution of volume takes place the decrease is read off. The carbonic acid is thus removed.

3. A solution of pyrogallic acid containing 1 gramme of the acid in 5 or 6 c. c. of water is introduced into the same measuring tube by means of another pipette similar to the above. The mixed fluid (the pyrogallic acid and the solution of potash) is spread over the inner surface of the tube by shaking the latter, and when no further diminution of volume is observed the residuary nitrogen is measured.

4. The solution of pyrogallic acid mixing with the solution of potash of course dilutes it, causing thus an error from the diminution of its tension; but this error is so trifling that it has no appreciable influence upon the results. It may, moreover, be readily corrected by introducing into the tube, after the absorption of the oxygen, a small piece of hydrate of potash, corresponding to the amount of water in the solution of the pyrogallic acid.

There is another slight error on account of a portion of the fluid adhering to the inner surface of the tube, so that the volume of the gas is never read off with absolute accuracy.

In conducting these endiometric experiments the necessary corrections for temperature and barometric pressure must, of course, be made.

Estimation of the Nitrogen. The amount of this gas is usually determined by deducting the aqueous vapours, oxygen and carbonic acid, from the volume of air examined.

Determination of Ammonia and Organic Matter. These are best determined by drawing a known volume of air through absolutely pure water. To obtain this latter it is best to redistil distilled water, to reject the first portions, then to add an alkaline solution of permanganate of potash, and to discard any portions of the distillate which give the52 slightest reaction with the Nessler test. The water through which the air is drawn must be kept cool, and afterwards submitted to the proper tests, which will be found under Ammonia and Water Analysis. Mr Blyth says, “Solid bodies such as vibrionic germs, dust, fungi, &c., may be obtained by using an aspirator, and drawing the air either through a drop of glycerine or water. Organic matter may also be obtained by suspending glass vessels filled with ice water, over or in the places to be investigated, and submitted to the microscope. High powers, such as immersion lenses, are requisite for the investigation of germs,” &c.

Of these germs Dr Angus Smith says:—“They may probably be divided into many kinds—the useful and the deleterious, those which promote health and those which bring disease. The idea of any of them bringing health is not founded on anything positive, but we can scarcely imagine these numberless forms to be all useless. The idea that they bring disease is, I think, one well confirmed.” See a paper by the same author “On the Air and Rain of Manchester.” ‘Memoirs of the Literary and Scientific Society of Manchester,’ vol. x. See Air, Vitiated.

AIR-GAS. Air deprived of its carbonic acid and moisture, and then impregnated with the vapours of very volatile fluid hydrocarbons, such as benzine and benzoline, can be used as an illuminating agent. It is requisite, however, to use burners with wide openings, and to apply a low pressure, because if the current be too rapid the flame becomes too much cooled, and is readily extinguished. Apparatus for preparing air-gas have been devised and constructed by Marcus, Mille, Methei, and others.

AIR-PUMP. An instrument designed for the removal of air from closed vessels. The simplest form of air-pump is the exhausting syringe, which consists of a cylinder fitted with a stop-cock, and having a valve at the bottom opening inwards. Another valve opening outwards is attached to a piston working inside the cylinder, and by screwing the instrument on to a vessel, and alternately elevating and depressing the piston, all except a very small quantity of residual and comparatively inelastic air is pumped out of the vessel (Figs. a and b). The accompanying figures show relative positions of the valve during (a) the elevation, and (b) the depression of the piston. In the usual and more convenient form of air-pump, a brass tube passes from the bottom of the syringe and terminates in the centre of a disk of brass or glass ground accurately; the vessel from which the air is to be exhausted has its edge very accurately ground, and is mounted upon the plate as shown in the subjoined figure.

This consists of a wide glass tube, a, into which another tube, b, b′, b′′, passes air-tight. c is an india-rubber tube connecting a with the water supply, d is a clamp to stop the flow of water through c. e is another clamp to regulate the flow, f is a reservoir to prevent any water which may accidentally come over from getting into j. g is a plug to let out any water from f. h is a screw for connecting a air-tight to a piece of tubing, which should pass 32 feet, if possible, below the level of a. i is a piece of strong india-rubber tubing to connect the pump with the vessel to be exhausted. The water rushes in at c and down h, carrying bubbles of air with it till the exhaustion is complete. The figure illustrates a common application of this pump to the rapid filtration of liquids which ordinarily pass through paper with difficulty. a is represented as being about half full of water. k is a funnel fixed air-tight in the india-rubber stopper of the bell-jar j. l is a small cone of platinum foil to prevent the paper filter which fits into it from being broken. m is a plate of ground glass, n is a beaker to receive the filtrate.53

Air-pump, Sprengel’s. This apparatus depends on the principle of converting the space to be exhausted into a torricellian vacuum.

In the subjoined figure, c, d is a glass tube longer than a barometer, open at both ends, and connected by means of india-rubber tubing with a funnel, A, filled with mercury and supported by a stand. Mercury is allowed to fall in this tube at a rate regulated by a clamp at C; the lower end of the tube, c, d, fits in the flask B, which has a spout at the side a little higher than the lower end of c, d; the upper part has a branch at x to which a receiver R can be tightly fixed. When the clamp at C is opened, the first portions of mercury which run out close the tube and prevent air from entering below. As the mercury is allowed to run down the exhaustion begins, and the whole length of the tube from x to d is fitted with cylinders of air and mercury, having a downward motion. Air and mercury escape through the spout of the bulb B, which is above the basin H, where the mercury is collected. It is poured back from time to time into the funnel A, to be repassed through the tube until the exhaustion is complete.

AIRY’S (Dr.) NATURE’S MEDICAL TREATMENT is the title of a pamphlet which recommends four secret remedies against 166 diseases:

a. The Pain Expeller, a mixture of about 35 parts of tincture of capsicum, 20 parts of diluted spirit, and 20 parts of spirit of ammonia.

b. Sarsaparillian, a fluid extract of sarsaparilla and China root, containing 1 per cent. of iodide of potassium.

c. Pills composed of powdered iron, jalap resin, jalap powder, and marsh mallow powder, made into a mass with some bitter extract. Each pill weighs 0·1 gramme.

d. Calming Pastilles are thick, hard tablets, composed of sugar, with oil of anise, and coloured with liquorice juice. (Hager.)

AKUSTICON (an ear essence). A proved remedy for every kind of ear disease, by Pserhofer. This may be imitated by dissolving in common glycerine one fifth of its weight of fir tar, filtering, and adding a few drops of cajeput oil dissolved in spirit (Hager.)

AL-. [Ar.] An inseparable article equivalent to the English the. It is found in many chemical and other words derived from the Arabic; as alchemy, alcohol, alembic, almanac, &c.

AL′ABASTER. Syn. Albâtre, Fr.; Alabas′ter, Alabastri′tes, Alabas′trum, L. A54 soft, white species of calcareous and of gypseous stone, used by sculptors. There are several varieties, all of which may be ranged under two heads:—

1. Calca′′reous alabaster; Orient′al, a.; Calc-sin′ter. A sub-variety of carbonate of calcium, formed by the deposition of calcareous particles in the caverns of limestone rocks. It has a foliated, fibrous, or granular structure, and a pure, soft, rich, semi-translucent whiteness, generally agreeably variegated with undulating zones or stripes of various shades of yellow, red, or brown. This variety is that most esteemed by sculptors, and for the manufacture of alabaster ornaments. The ancients used it for ointment and perfume boxes. At the baths of San Filippo (Tuscany), the process of its formation may be examined by the observer. The natural spring of boiling water holds carbonate of lime in solution by means of sulphuretted hydrogen, which, escaping into the air, leaves the lime as a precipitate, which is gradually deposited in a concrete form. (M. Alex. Brogniart.)

2. Gyp′seous or common alabaster; Gypsum. A natural hydrated sulphate of calcium, containing a little carbonate of calcium. That from the quarries of the Paris basin contains about 12% of the latter substance. When calcined or roasted, and powdered, it forms the substance known under the name of Plaster of Paris. The more compact, fine-grained specimens of this variety are, like the preceding one, sculptured into almost numberless articles of ornament and utility, such as vases, clock-stands, statuettes, &c. The inferior kinds only are manufactured into the ‘plaster of Paris’ of the shops. The best specimens are obtained from the lower beds of the gypsum quarries, and are white, and granular, not unlike Carrara marble. It takes a high polish; but from its softness and liability to become discoloured, articles formed of it require more careful treatment than even those of ‘calcareous alabaster.’

Alabaster is wrought, turned, and fashioned, in a nearly similar manner to the softer varieties of marble. The tools resemble those employed for the like operations in ivory and brass. Machinery is now often applied to this purpose.

Alabaster is polished, first with pumice-stone, and then with a paste or pap made of whiting, soap, and milk or water; and lastly, with dry flannel. A better method, however, is to rub it first with dried shave-grass (equisetum), and afterwards with finely powdered and sifted slaked lime formed into a paste with water. The surface is then ‘finished off’ by friction with finely powdered talc or French chalk, until a satiny lustre is produced, or with putty powder, in a similar way to marble.

Alabaster is engraved with tools resembling those employed for other soft minerals. It is etched by covering every part of the surface, except that to be acted on, with a solution of white wax in oil of turpentine (1 to 4), thickened with a little finely powdered white lead, and subsequent immersion in water acidulated with acetic acid or hydrochloric acid, for the calcareous variety; and in spring water, for 20 to 50 hours (according to the effect desired), for the gypseous variety. The varnish is washed off with oil of turpentine, and the etched parts carefully brushed over with finely powdered gypsum.

Alabaster is joined and repaired by means of white of egg, or rice glue, thickened with finely powdered quicklime; or by a paste of newly baked and finely powdered gypsum, mixed up with the least possible quantity of water.

Calcareous alabaster is usually cleaned with a brush and warm soap-and-water, or with tepid water to which a few grains of carbonate of soda or of ammonia have been added; followed in either case by rinsing in clean water. If much discoloured, thoroughly cover the article with a paste of freshly slaked lime and water, and let it remain twenty-four hours; then wash off the paste with soap and water, rubbing hard the stains.

Delicate objects in gypseous alabaster can only be safely cleaned with benzol, or with pure oil of turpentine. If necessary, the surface must be repolished. Grease spots may be removed from either variety with a little benzol or oil of turpentine.

Alabaster is occasionally stained or coloured, and, for the calcareous variety, in a similar way to marble, except that heat is not employed; and for the gypseous variety, in the manner noticed under Plaster OF Paris. The gypseous variety is also bronzed and hardened in a similar way to that adopted for casts in the latter substance.

Obs. Gypseous alabaster is dissolved by water; and the beauty of both varieties is almost irrecoverably destroyed by grease, coloured oils, varnishes, smoke, &c. It is, therefore, unfitted for garden ornaments, or other objects exposed to the rain or weather, unless it be painted or bronzed; and is even then very perishable. Contact with acids, alkalies, and ammoniacal and sulphurous fumes, also injure, and, if prolonged, destroy it. Even an uncorked phial of smelling-salts placed on a mantel-piece beside an alabaster vase will soon destroy its beauty. Thus, all delicate objects in alabaster should be protected by a glass shade.

Alabaster, Orient′al (Factitious). Figures, basso relievos, &c., of considerable hardness and beauty, may be formed by imitating the process adopted at the baths of San Filippo, before referred to.

Proc., &c. Moulds of sulphur are placed either vertically or obliquely in an open tub or cistern, having a freely perforated bottom. Surmounting the whole are two or more pieces of wood in the form of a cross or star. The sulphurous calcareous water, falling on this55 cross, is scattered into spray or streamlets, and losing the gaseous portion which holds the lime in solution, deposits it in the form of oriental alabaster on the surface of the moulds. In from 1 to 4 months, according to the nature of the article, a sufficiently thick deposit is obtained. The object is then removed from the mould, and trimmed and polished. It is found that the more vertical the position of the mould, the finer is the grain of the resulting deposit. The water of the Spring of San Filippo may be exactly and easily imitated by the chemist; and the whole process offers a new and valuable ornamental art for the amusement and profit of the ingenious and enterprising.

ALAMODE′ (ăl-ăh-mōdé). [Fr., à la mode.] According to the prevailing mode or fashion. In cookery, applied to several dishes, but more particularly to one of beef (alamode beef), commonly shortened by the lower class of Londoners into “alamode.” See Beef, Stewing, &c.

ALAN′TINE. [Eng., Fr., Ger.] Syn. Alanti′na, L. A substance identical with inulin, found in the roots of garden angelica (‘angelica archangelica,’ Linn.).

ALBA′TA. [L., Eng.] A name given to several alloys resembling silver. See Alloys, German Silver, &c.

ALBION (Parisian). “Will preserve the skin white and free from wrinkles.” An aromatic water with chloride of lead and calomel suspended in it. (Landerer.)

ALBOLITH. A cement powder prepared by W. Riemann, Breslau. Made with calcined magnesia (obtained from magnesite) and chloride of magnesium. It is recommended for painting walls, stairs, and wooden articles. (Hager.)

ALBU′MEN. [Eng., L.] Syn. Albumin; Albumine, Fr.; Eiweiss, Eiweistoff, Ger. Literally, the white of egg; a peculiar nitrogenous substance which enters largely into the composition of animal bodies. It abounds in the blood, muscles, bones, coagulable lymph, vitreous and crystalline humour of the eye, fluid of dropsy, &c. The white of egg consists of nearly pure albumen dissolved in water.

A substance identical with albumen is found in many vegetables. It enters largely into the composition of all the emulsive seeds. According to Seguin, it exists in considerable quantity in all those vegetables and fruits that afford a vinous liquor without the addition of yeast.

Prep. The white of egg and the serum of blood, when strained through muslin, furnish albumen, in solution, in a sufficiently pure state for all the ordinary purposes of the arts. Pure solid albumen may be prepared as follows:—

1. Agitate strained white of egg with 10 or 12 times its bulk of alcohol, collect the precipitated flocculi on a muslin filter, and suffer it to dry at a temperature not exceeding 120° Fahr.

2. Add a little water to white of egg, mix, filter, exactly neutralise with acetic acid, and then largely dilute with pure cold water; the precipitate which falls may be collected on a filter and washed. Strained serum of blood may be used instead of white of egg, in both the above forms.

Comp., &c. The following is the composition of albumen according to Lieberkühn:—

Carbon	53·3
Hydrogen	7·1
Nitrogen	15·7
Oxygen	22·1
Sulphur	1·8
	——
	100·0

Chatin found iodine in the white of egg; it also contains chloride, sulphate, phosphate, and carbonate of sodium, phosphate of calcium, and traces of potassium in it; but, unlike the sulphur, none of these substances form a constituent part of pure albumen, though probably always present in white of egg.

Prop. Pure solid albumen (unaltered by heat) is nearly colourless, inodorous, and tasteless; scarcely soluble in water, but readily so in water, containing an exceedingly small quantity of caustic soda or potash, and in a strong solution of nitrate of potassium. When dried by a gentle heat it shrinks into a translucent horny mass; and when exposed to a sufficient temperature, yields the usual ammoniacal odour and products of animal matter. Its solution (as white of egg) is solidified or coagulated by a heat of from 145° to 165° Fahr., forming a white, opaque mass; when very dilute, on boiling (only) it separates in fine light flocks. When thus coagulated, it is insoluble in water at a less temperature than 302° Fahr. (Wöhler and Vögel), unless alkalised. Ordinary solutions of albumen give precipitates with sulphuric, hydrochloric, nitric, and metaphosphoric acids, with tannin and astringent solutions, and with most of the metallic salts; but are not affected by either acetic acid or tribasic (common) phosphoric acid. Alcohol, in quantity, also precipitates albumen. Strong oil of vitriol turns it black in the cold, but on applying a gentle heat, a gorgeous, red-coloured liquid is produced. Strong hydrochloric acid gives a deep violet-blue solution. White of egg or serum exposed in a thin stratum to the air, dries up into a pale, yellow, gum-like substance, and in this state may be kept for any length of time, retaining its property of redissolving when immersed in slightly warm water.

Tests.—1. Both heat and alcohol (or strong spirit) coagulate it:—2. A solution of perchloride56 of mercury dropped into a fluid containing albumen occasions a white precipitate:—3. Subacetate of lead acts in the same way. Either of the last two will render turbid a solution containing only the 1-2000th part of fresh white of egg, or the 1-10,000th part of dry albumen:—4. Tannin and tincture of galls give yellow, pitchy precipitates:—5. If dry caustic potash or soda be triturated with either liquid or solid albumen, ammoniacal fumes are evolved, and the mixture on calcination yields ferrocyanide of potassium:—6. Its coagulability by heat, and its incoagulability by acetic acid, distinguish it from casein.

Uses, &c., Independently of its value as an alimentary substance, albumen is largely employed in photography as a glaze or varnish, for fixing colours in calico printing, as a cement, &c., and more particularly as a clarifier for wines, syrups, vegetable solutions, and other liquids. Its efficacy for the last purpose depends on its entangling the impurities in its meshes during coagulation, and either rising to the surface with them as a ‘scum,’ or sinking with them as a precipitate. In France it is prepared on an extensive scale, at the abattoirs, by being spread in thin layers to dry; the source of supply being of course the stream of the blood of the slaughtered animals. When the liquid operated on does not spontaneously coagulate albumen, it is necessary to apply heat to it. In cases of poisoning by the mineral acids, corrosive sublimate, nitrate of silver, sulphate of copper, bichloride of tin, or sugar of lead, the white of egg (or indeed the yolk as well) is one of the best antidotes that can be administered.

Albumen, Flake. Syn. Albumen in powder, Solid a., Soluble a., Planter’s a. Prep. Expose strained white of egg or serum of bullock’s blood, in a thin stratum, to a current of dry air, until it concretes into a solid transparent substance, resembling horn. In this state it may be kept any length of time, or it may be further dried until brittle, and then reduced to coarse powder.

Use. It is extensively employed as a ‘clarifier’ in the sugar plantations of the West Indies, and elsewhere. It is prepared for use by soaking and stirring it with cold water until it is dissolved, when it is whisked to a froth in the usual way, and agitated with the liquid to be clarified.

Albumen, Iodised. 1. To the white of every egg employed add 7¹⁄₂ grains of iodide of potassium dissolved in an equal weight of distilled water. Beat the mixture to a froth, let it stand until insoluble matters have settled, pour the clear portion into a wide-mouthed bottle, and keep in a cool place. 2. Dissolve 50 grains of iodide of potassium and 10 grains of bromide of ammonium in 2¹⁄₂ oz. of distilled water, and add 120 minims of strong liquor ammoniæ. Add this solution to 10 oz. of albumen, let the mixture stand to settle, and filter. This preparation is said to keep good for a long time.

Albumen, Solution of (B. P.). Take of white of one egg; distilled water, four fluid ounces. Mix by trituration in a mortar, and filter through clean tow, first moistened with distilled water. This solution must be recently prepared.

Albumen, Vegetable. This substance, long considered to be a distinct proximate principle peculiar to the vegetable kingdom, has been shown, by recent researches, to be identical with animal albumen. It is particularly abundant in carrots, turnips, cabbages, green stems of peas, and oleaginous seeds.

ALBU′MEN. In botany, the solid, fleshy, or horny substance found in many seeds, between the integuments and the embryo. It is the part that furnishes the flour of the ‘cereals,’ the flesh of the ‘cocoa-nut,’ and the great mass of the seeds of coffee and other vegetables. However poisonous the plants which produce it may be, this substance is never deleterious.

ALBUMENISED PAPER. A French paper highly glazed, having a fine surface, and made by Rive; a German paper having a more uniform texture, and made by Saxe; also a paper by Towgood, are recommended for the preparation of albumenised paper. Positive paper may be albumenised as follows:—Add 15 grains of finely pulverised common salt to the white of every egg used, and whisk until the mixture is entirely converted into a white froth. Allow this froth to stand in a glazed earthenware pan which must be rather larger than the sheets of paper to be albumenised, for about twelve hours. At the end of this pour the clear portion of the liquid into a flat porcelain tray. Mark the inferior side of the paper, slightly damp it, lift it by its ends, and float it carefully on the prepared albumen, keeping its inferior and dry side uppermost. Then raise the paper at each end, and if any air bubbles are seen remove them with a card or brush and replace the paper in the bath. Remove the paper from the bath and suspend it at the corners by clips. Albumenised paper should be kept dry by enclosing it in tin or zinc cases.

ALBU′MENOUS. Syn. Albumino′sus, L.; Albuminé, Abumineux, Fr.; Eiweisstoffhaltig, Ger. Formed of, containing, or having the properties of albumen.

Albuminous Plants. In botany, all plants whose seeds contain albumen in a separate state; as in the cereals, palms, &c.

ALBURN′UM. [L.] Syn. Alburn*; Sapwood. In botany, the white and softer parts of the wood of exogenous plants, lying between the inner bark and the heartwood. It consists of empty or nearly empty tubes or57 cells, which gradually acquire solidity by the deposition of resins, tannin, and other products of vegetation, and in time becomes wood. It is through the alburnum that the ascending sap chiefly flows.

ALCARAZ′ZA. [Sp.] A species of porous earthenware, or a vessel formed of it, made in Spain from a light, sandy marl, and but slightly fired. Their value as ‘coolers’ arises from the copious evaporation of the water, which gradually transudes. A similar ware and articles are made in France, under the name of HYGROCERA′MEN; and in England, under the names of POROUS WARE, WATER COOLERS, WINE COOLERS, BUTTER COOLERS, &c. The following are forms said to be used in our potteries:—

Prep. 1. Take of sandy marl, 2 parts; brine, q. s.; make a dough, and then knead in of common salt, in fine powder, 1 part. Bake the pieces slowly, and lightly.

2. Good clay, 2 parts; fine siliceous sand, 3 parts; brine, q. s.; common salt, 1 to 2 parts; as before.

3. Powdered clay, 2 parts; powdered charcoal, 3 parts (by weight); water q. s. to form a stiff dough. The kilning must be so arranged that the heat is applied gradually, and the vessels exposed to a current of hot air; and it must be continued until all the charcoal is burnt out, carefully avoiding over-firing.

AL′CHEMY (-kĭm-). Syn. Al′chymy (-kĭm-); Hermetic Art*; Alchem′ia, Alchym′ia, L.; Alchimie, Fr.; Alchemie, Ger.; Alchimia, It. The romantic forerunner of the modern science of chemistry. An imaginative art or science, having for its objects the discovery of a substance (PHILOSOPHER’S STONE) capable of transmuting the baser metals into gold—a panacea, or universal remedy (ELIXER VITÆ), by which disease and death were to be avoided by its possessor—an alkahest, or universal solvent—a universal ferment; and other like absurdities. A mixed metal formerly used for utensils was also called by this name.

AL′COHOL. C₂H₆O. [Eng., L.; B. P.] Syn. Al′kohol, Eng., L.; Alcoöl, Alcohol, Fr.; Alkohol, Höchst Rectifieirter Wein-geist., Ger.; Alcoöle, It. A term commonly applied to one kind of spirit—that obtained by the distillation of any fermented saccharine liquid, and forming the characteristic principle of wines, beers, spirits, and other intoxicating liquors.

Etym. Kohol, a Hebrew-Syriac word, is the name given to a preparation of powdered antimony used by Oriental ladies to paint their eyebrows. In course of time this term was applied to other fine powders, and ultimately to highly rectified spirits.

Hist., &c. Although the art of distillation was probably known at a comparatively early age of the world, the preparation of pure rectified spirit is a discovery of modern times. It was not until the 13th century that Raymond Lully first showed the way to concentrate spirit by means of carbonate of potash; after which date pure concentrated spirit gradually rose into note as an article of trade and commerce in Europe. In the 16th century its distillation was in common practice in these countries. (Burns.) By means of chloride of calcium, Dr Black obtained alcohol of sp. gr. 0·800 (about A.D. 1760); and Richter afterwards procured it of a sp. gr. so low as 0·796 at 60° Fahr. (Crell’s ‘Annals,’ 1796.) Lavoisier first demonstrated the composition of alcohol (about 1780). Its analysis was subsequently perfected by M. Saussure, jun., and confirmed by MM. Dumas and Boullay, and Gay-Lussac; and by many others since.

Nat. Hist. Alcohol is peculiar to the organic kingdom, being exclusively produced, in the natural way, by the process of fermentation.

Sources, &c. Dilute alcohol may be procured, by the ordinary process of distillation, from all fermented liquors. When drawn from wine (as in France), it constitutes BRANDY; when from the refuse juice of the sugar-cane, it is called RUM; when from malt, grain, or molasses (as in England), it is called MALT, RAW-GRAIN or MOLASSES SPIRIT; and when from rice or palm-wine, ARRACK. Brandy, rum, Hollands, and whisky, contain only about half their volume of alcohol; and gin much less. When distilled from any of these spirituous liquors, the alcohol contains, besides water, variable quantities of essential oils, ethers, and other flavouring matters, which, by one or more redistillations with charcoal or lime, it for the most part loses, and then becomes commercial spirit of wine. By a further rectification from chloride of calcium, lime, carbonate of potash, or any other substance having a strong affinity for water, the water is retained, and a strong spirit passes over containing not more than 10 per cent. of water. By repeating the process, and using the proper precautions, it may be obtained almost entirely free from water, and is then called absolute or anhydrous alcohol.

a. Alcohol (highly rectified spirit), of 85% (sp. gr. ·835 to ·822), is mixed, in a tubulated retort, with about half its weight of fresh-burnt quick-lime, in coarse powder; and the whole, after securely stopping the neck with a cork, and agitation, is allowed to repose for several days. The alcohol is then carefully distilled off, drop by drop, by the heat of a water bath, until the weight of the distillate nearly equals that of the ‘anhydrous alcohol’ in the spirit operated on. The sp. gr. of the product should be ·795 or ·796; but by carefully repeating the process with the distillate and a fresh quantity of lime, and prolonging the last digestion with the latter for several weeks, absolute alcohol of the sp. gr. ·79381 at 60° Fahr. may be easily obtained.

b. (Drinkwater; Fownes.) The strongest58 rectified spirit of wine is digested in a stoppered bottle for several days, with about half its weight of anhydrous carbonate of potash, in powder, frequent agitation being had recourse to; the alcohol, after repose, is then decanted, and treated with sufficient fresh-burnt quick-lime to absorb the whole of the spirit. After 48 hours’ digestion, the spirit, when distilled, will have the sp. gr. ·793 at 60° Fahr.

c. (Liebig; Ure.) Alcohol of about 90% is saturated with fused chloride of calcium, in powder, and after repose for a few hours in a stoppered bottle, is submitted to distillation as before. The product should nearly equal the quantity of dry alcohol in the sample. Ure recommends equal weights of the spirit and chloride to be taken; and the process to be stopped as soon as about half the volume of the spirit employed has passed over, or the distillate acquires a higher sp. gr. than ·791 at 68°, or ·796 at 60° Fahr.

d. (B. P. 1867.) Take of rectified spirit, 1 pint; carbonate of potash, 1¹⁄₂ ounce; slaked lime, 10 ounces. Put the carbonate of potash and spirit into a stoppered bottle and allow them to remain in contact for two days, frequently shaking the bottle. Expose the slaked lime to a red heat in a covered crucible for half an hour, then remove it from the fire, and, when it has cooled, immediately put the lime into a flask or retort, and add to it the spirit from which the denser aqueous solution of carbonate of potash, which will have formed a distinct stratum at the bottom of the bottle, has been carefully and completely separated. Attach a condenser to the apparatus, and allow it to remain without any external application of heat for twenty-four hours; then applying a gentle heat, let the spirit distil until that which has passed over shall measure 1¹⁄₂ fluid ounce; reject this, and continue the distillation into a fresh receiver until nothing more passes at a temperature of 200° Fahr.

e. (Poggendorff.) Saturate alcohol with caustic potash, then add half its volume of water, and distil at a low temperature.

a. (Alcohol, Ph. L. 1836.) Take of rectified spirit (sp. gr. 0·838), 1 gal.; chloride of calcium, 1 lb.; proceed as above, and distil 7 pints and 5 fl. oz. Sp. gr. of product 0·815. It contains about 7% of water, by weight, and 5% by volume.

b. (Alcohol, Ph. D. 1826.) Rectified spirit, 1 gal.; pearl-ashes (dried and still hot), 3¹⁄₂ lbs.; mix, digest in a covered vessel, with frequent agitation, for seven days; then decant the clear portion, and add to it of chloride of calcium, 1 lb.; agitate to effect solution, and distil off the spirit until the mixture in the retort begins to thicken. Sp. gr. of product 0·810. It contains about 5% of water, by weight.

c. (Without distillation.) Rectified spirit is agitated, in a closed vessel, with anhydrous carbonate of potash (prepared by heating the salt to redness, and still slightly warm), until the powder sinks to the bottom undissolved; the carbonate is then added in considerable excess, and the agitation repeated at short intervals for some hours or even days; lastly, after sufficient repose, the clear upper portion is decanted.—Obs. If a clean spirit, and pure carbonate of potash (or at least one perfectly free from caustic potash or any other impurity soluble in strong spirit), be used, an alcohol sufficiently pure and free from water for many common purposes may be thus obtained; otherwise the product contains a little potassa, &c., which can only be removed by distillation. For some purposes, however, this would not be objectionable. Sp. gr. about ·812.

III. (Soëmmering.—Varnish-maker’s alcohol.) The bladder of an ox or calf, thoroughly cleansed from fat, and washed and dried, is nearly filled with rectified spirit, and then securely fastened and suspended in any dry situation, at a temperature of about 122° Fahr. In from six to twelve hours, when the heat is properly maintained, the spirit is generally sufficiently concentrated, and in a little time longer is rendered nearly free from water (anhydrous), or of the strength of 96 to 98%.—Obs. The same bladder will serve for more than one hundred operations. If not kept very nearly full, a portion of the spirit escapes through the empty part. To prevent this accident, a bottle with a double neck, of the shape represented in the engr., may be employed; by which means the bladder may be kept constantly full during the process. After the first or second time of using, the bladder gives alcohol sufficiently pure for all ordinary purposes. Before hanging the apparatus up, it is better to enclose it in a coarse potato-netting, to prevent any accident arising from the strain on the neck of the bladder. Soëmmering recommends both the inside and outside of the dry bladder to be smeared over59 2 or 3 times with a strong solution of isinglass; but this is not necessary to the success of the process.

IV. Rectified Spirit. (B. P. 1867.) Spiritus Rectificatus. Alcohol with 16 per cent. of water; obtained by the distilling of fermented saccharine fluids. Sp. gr. 0·838.

V. Proof Spirit. (B. P. 1867.) Spiritus Tenuior. Take of rectified spirit, 5 pints; distilled water, 3 pints. Mix. Sp. gr. of product 0·920.

Prop. of Alcohol. Light, transparent, colourless; highly volatile and inflammable, burning with a pale blue and smokeless flame; very mobile; odour, agreeable; taste, strong and pungent; miscible in all proportions with water, with the evolution of heat, and temporary expansion, but ultimate condensation of the mixture, some hours elapsing before the union is complete, and the normal temperature restored. The mixture has a higher sp. gr. than the mean of its constituents; and this is greatest when 54 vols. of alcohol are mixed with 49·77 vols. of water, the resulting compound measuring only 100 volumes. It absorbs water from moist air; dissolves resins, essential oils, camphor, bitumen, soaps, sugar, carbonic and boracic acid, iodine and the iodides, lime, ammonia, soda, potash, the alkaloids, wax and spermaceti (when boiling), all the deliquescent salts (except carbonate of potassa), and various other substances. It curdles milk, coagulates albumen, and (in quantity) separates both starch and gum from their mucilages. It boils, in the air, at 173° Fahr., when in the anhydrous state. When diluted with water its boiling point rises in proportion to the amount of water added. It boils, in vacuo, at 56° Fahr. Every volume of boiling alcohol yields 488·3 vols. of vapour at 212° Fahr. Its sp. gr. is 0·793811 at 60° Fahr., that of its vapour being 1·6133. It has never been frozen; when cooled to -166° Fahr., it acquired the consistence of castor oil, but did not solidify. It contracts by cold; between -15° and +99° Fahr., this occurs with great regularity, at the rate of ·00047 part of its volume for every degree of the thermometer. Its evaporation, like that of ether, produces intense cold. The products of its combustion are carbonic anhydride and water. It acts as a powerful antiseptic on organic substances immersed in it, and is in consequence extensively employed in the preservation of anatomical preparations. With the acids it forms ethers.

Phys. eff. Alcohol is a narcotico-acrid poison. In small doses it occasions excitement and intoxication; in larger ones, delirium, somnolency, coma, apoplexy, and death. It acts as a violent nervous stimulant, and, by abstracting water from the soft tissues of the stomach and primæ viæ, destroys their organisation. It is alike poisonous to all animals;—2 drs. will kill a dog. All strong spirits act in the same way, the effect being proportionate to the state of concentration and the quantity taken. On plants it acts as a rapid and fatal poison.

Ant., &c. Copious internal use of tepid water, with cold affusions to the head and spine, and injection of cold water into the ears. In the absence of vomiting, a strong emetic should be given, or the stomach-pump used. Ammonia may be used as a stimulant, and, added to water just in sufficient quantity to flavour it, is one of the best antidotes. The head should be kept elevated, and bleeding had recourse to, if cerebral congestion threatens.

Tests in cases of death. 1. The odour of the contents of the stomach and ejected matters, and their ready inflammability. 2. The spirit may be separated by digestion with water, filtration, the addition of carbonate of potash, and distillation.

	Dumas and Boullay.	Brande and Ure.	Ure. sp. gr. 0·812.
Carbon	52·37	52·18	47·85
Hydrogen	13·01	13·04	12·24
Oxygen	34·61	34·78	39·91
	————	————	————
	99·99	100·00	100·00

This nearly represents 2 equivalents of carbon, 3 eq. of hydrogen, and 1 of oxygen. The atom of alcohol is now regarded as a multiple of these numbers, and formed by the breaking up of one atom of grape sugar (C₁₃H₂₈O₁₁) into 4 eq. of alcohol, 8 eq. of carbonic acid, and 4 eq. of water. It was formerly regarded as a compound of 1 eq. of olefiant gas, and 1 eq. of water; but it is now generally viewed as HYDRATE OF THE OXIDE OF ETHYLE (C₂H₅.HO), or a compound of ethylene and water (C₂H₄.H₂O). Grape sugar alone yields alcohol; cane sugar, before it undergoes the vinous fermentation, being first converted into this substance by contact with the ferment.

Purity. The presence of water is shown by the specific gravity (see Alcoholometry); the absence of other foreign matter by the following tests:—

1. Its colour and transparency is not affected by the addition of a little colourless oil of vitriol (Liebig), or by a solution of nitrate of silver, and subsequent exposure for some time to solar light (Vögel), unless either essential oil or organic matter be present, when it assumes a reddish tinge. 2. It should be neutral to test-papers, colourless, leave no residue on evaporation, and be miscible, in all proportions, with water and with ether. 3. Its boiling point should never be less than 170° Fahr.; a lower temperature suggests the presence of wood spirits, or acetone, or one of the ethers. To detect wood spirit (wood naphtha) see Nessler’s Test. For the reverse of this adulteration—the evasion of the duty by the introduction of spirit, under the disguise of naphtha, turpentine, &c.—see those articles.60

4. The presence of water in alcohol may be detected, not only by the sp. gr., but also by white anhydrous sulphate of copper burning blue when dropped into it. 5. Potassium placed on alcohol does not take fire, unless a considerable per-centage of water be present.

Tests, &c. 1. It may generally be recognised by its volatility, inflammability, odour, taste, miscibility with water, power of dissolving camphor and resins, and other qualities already described. 2. If a few fibres of asbestos be ‘moistened’ with a saturated solution of bichromate of potash in oil of vitriol, and exposed to the smallest possible portion of hot alcohol vapour, it is almost instantly turned green, owing to the formation of oxide of chromium. In practice, the asbestos may be inserted in the neck of a retort, or even of a bulbed glass-tube containing a few drops of the suspected solution, when the effect occurs as soon as distillation commences. Ether and pyroxylic spirit produce a nearly similar result; but the ‘first’ of these is distinguished from alcohol by its not being miscible with water in all proportions; and the ‘other’ by Nessler’s Test; whilst both may be readily distinguished by their peculiar and characteristic odour. 3. Dissolve 3 pts. crystallised carbonate of soda in 10 pts. water. To this solution add 1 pt. of liquid to be tested, and heat to about 160° Fahr. Lastly, add iodine in small pieces, till it has entirely dissolved, and the liquid has become colourless. If alcohol be present, iodoform will make its appearance on cooling, and sink to the bottom in the form of a yellow powder. As a similar result is obtained with wood spirit, this must be proved to be absent before applying this test.

The only reliable method of proving that a sample is ethylic alcohol is the production of ether, by acting on the suspected liquid with sulphuric acid. See Ether.

Uses. In the arts, alcohol is used by the varnish-maker to dissolve resins; by the perfumer, to extract the odour of plants, and dissolve essential oils, soaps, and other similar substances; by the pharmaceutist, to prepare tinctures and other valuable medicinals; by the instrument-maker, to fill the bulbs of thermometers required to measure extreme degrees of cold; by the photographer, in the preparation of collodion; by the chemist, in analysis, and in the manufacture of numerous preparations; by the anatomist and naturalist, as an antiseptic; and by the physician, for various purposes and applications as a remedy. It is also frequently burnt in lamps, and in parts of the world where it is inexpensive, it is employed in the manufacture of vinegar. Its uses, when dilute, as in the ‘spirituous liquors’ of commerce, are well known. In medicine, it is employed both concentrated (‘alcohol,’ ‘rectified spirit’) and dilute (‘proof spirit,’ ‘brandy,’ ‘gin,’ &c.), as a caustic, irritant, stimulant, tonic, &c. It has also been used in a multitude of other cases, and has been applied to an almost infinite variety of other purposes.

Gen. commentary. The selection of any one of the processes given above for the preparation of alcohol must greatly depend on the convenience or position of the operator. Chloride of calcium, and quick-lime, from their powerful affinity for water, and easy application, are the hygrometric substances most generally employed; but the processes involving the use of the other substances and methods already noticed, have all of them advantages under particular circumstances. Gay-Lussac has recommended the use of caustic baryta instead of lime; and others have employed dry alumina, as an absorbent of the water prior to distillation. Common proof spirit may be concentrated until its sp. gr. falls to about 0·825, by simple distillation in a water bath; at which sp. gr. it contains only about 11% of water, by weight, and is then nearly as volatile as pure alcohol.

A convenient apparatus for the preparation61 of alcohol, on the small scale, is that figured in the engr., and which will be self-explanatory to every one competent to use it. The tank (i) should be supplied with ice-cold water; and the receiver (g) should be covered with cloths kept continually wet with water of the same temperature. The capsule or basin (c) is a water bath heated by the little gas furnace (d). On the large scale, for commercial alcohol, a copper still, fitted with a glass refrigeratory and receiver, is commonly employed.

By surrounding the capital of a still, or other like apparatus, by a water bath kept at the proper temperature, the alcoholic richness or content of the product may be regulated to the greatest nicety, for any desired strength.

The different statements of chemical authors as to the boiling point, specific gravity, &c., of alcohol, already noticed, may be referred to their having either experimented with samples which have not been absolutely anhydrous, or to their not having made the proper corrections for temperature, and for the different materials of which their vessels and instruments were composed—some probably having been made of glass, and others of brass or some other metal. In some instances the differences are more apparent than real, as in the Tables by Tralles and Lowitz; in the former of which water, at its lowest sp. gr., is taken as the standard. Until recently, the only known source of alcohol was the fermentation of saccharine solutions. Its production by synthesis, though often attempted, is, however, erroneously said to have always failed. It had long been employed as an occasional source of bicarburetted hydrogen (olefiant gas) at a high temperature; but M. Berthelot succeeded in reproducing it, from bicarburetted hydrogen, by agitating the latter, in a closed vessel, with sulphuric acid and metallic mercury (‘Journ. de Chimie Med.,’ 1855, p. 175); and Henry Flennel, nearly thirty years before M. Berthelot’s discovery, found that pure olefiant gas is absorbed by agitation with concentrated sulphuric acid, with the formation of sulphovinic acid, and that by subsequent dilution with water, and distillation, alcohol passes over into the receiver.

ALCOHOLATE. Syn. Alcohate; Alcoholas, L. A salt in which alcohol appears to replace the water of crystallisation, as is the case with certain chlorides, nitrates, &c. Some of them may be formed by simple solution and crystallisation of the salt in alcohol. (Graham.) They are all very unstable, being readily decomposed by water.

ALCOHOLIC. Syn. Alcoholicus, L.; Alcoholique, &c., Fr.; Alkoholisch, Ger. Pertaining to, containing, of the nature of, or made with, alcohol.

ALCOHOLICA. [L.] Syn. Alcoöliques, Fr.; Weingeist-verbindungen, Ger. In pharmacy, liquids containing, or preparations made with, alcohol, as a characteristic ingredient.

ALCOHOLISATION. [Eng., Fr.] Syn. Alcoholisatio, L.; Alcoölisation, &c., Fr.; Alkoholiserung, Ger. In chem. and pharm., the development of the characteristic properties of alcohol in a liquid, or the use of it either as an addition or a menstruum; also the act or process of obtaining alcohol from spirit by rectification.

ALCOHOLOM′ETER (-lŏm′-). Syn. Alcohol′meter (hŏl′-; -hŏm′-‡); Alcoholométrum, L.; Alcoölomètre, Alcoömètre, Alcoholmètre, &c., Fr. An instrument or apparatus used in alcoholometry. Alcoholometers are simply ‘hydrometers’ adapted to the densities of alcohol, either concentrated or dilute. Some of these, as Baumé’s, Carter’s, &c., merely indicate the number of degrees corresponding to the state of concentration of the liquid. Others, of a like construction, as those of Richter (a), Tralles (b), and Gay-Lussac (c), have their stems so graduated as at once to indicate the proportion per cent. of alcohol present, either by weight, or by volume, at some standard temperature. (See engr.) A third class, as those of the Abbé Brossard-Vidal, Field, &c. are essentially thermometers, with scales which indicate the boiling points of spirits of different strengths, instead of the common thermometric degrees; whilst to a fourth class belong the alcoholometer of M. Silbermann, which is based upon the known rate of expansion of alcoholic liquors by heat, expressed in alcoholometric degrees; and that of M. Geissler, which depends on the measurement of the tension of the vapour of the liquid, as indicated by the height to which it raises a small column of mercury. In Syke’s hydrometer, used by officers of the Revenue, the scale of the instrument is enormously extended by the use of movable weights, with each of which it becomes, in fact, a separate instrument, adapted to a certain range of specific gravities.

A very convenient alcoholometer for ordinary purposes (d) has been lately produced by some of the instrument makers. It is of the usual form, but its stem on one side exhibits the per-centage richness of the sample in alcohol by volume; and on the other, the per-centage by weight. Thus, both results may be obtained at one trial. This instrument is sometimes called Richter’s alcoholometer, in England. A further improvement, still more recently introduced, is a similar ‘double-scale’ instrument, showing the degrees of Sykes on one side, and carrying a small spirit-thermometer in the bulb, to which62 a scale is fixed ranging from 35° to 82° Fahr.

ALCOHOLOM′ETRY. Syn. Alcohol′metry (-hŏl′-; -hŏm′-‡); Spirit testing‡; Alcoholme′tria, L.; Alcoölométrie, Alcoömétrie, &c., Fr. In chemistry, the art or process of ascertaining the richness of spirits in alcohol. In commerce, the determination of the quantity of spirit of a certain strength, taken as a standard, present in any given sample of spirituous or fermented liquors. In England, this standard is called “proof spirit.”

Hist., &c. The great importance of being able accurately to determine the strength of spirits in the United Kingdom, on account of the high duties levied on them, has induced the Government authorities, at various times, to investigate the subject. In 1790, the matter was referred to Sir C. Blagden, then Secretary to the Royal Society, who instituted an extensive series of experiments to determine the real specific gravities of different mixtures of alcohol and water. The results of his labours and researches were put forward, with ‘Gilpin’s Tables,’ in 1794, but no practical measures appear to have been taken in consequence. In 1832 a committee of the Royal Society, at the request of the Lords of the Treasury, examined into the accuracy of the Tables, and the construction and application of the instrument (Syke’s hydrometer) now used by the Revenue officers, on which they reported favorably, and declared that they were sufficiently perfect for all practical and scientific purposes. The errors introduced into calculations of the strength of spirits by these tables were found to be quite unimportant in practice, and did not, in any one instance, amount to unity in the fourth place of decimals. This method adapts the specific gravity as the test of the strength of spirits, and is founded on the fact that alcohol is considerably lighter than water, and that (with proper corrections for condensation and temperature) the sp. gr. regularly increases, or decreases, according to the relative proportions in which the two are mixed.

Several other methods of alcoholometry have been proposed, founded upon—the variations in temperature of the vapour of alcohol of different strengths—the heat involved by its admixture with water—its dilatation by heat—the tension of its vapour—the insolubility of carbonate of potash in alcohol—its volatility, boiling point, &c. &c., the more important and useful of which are noticed further on. The method adopted by the Boards of Inland Revenue and Customs is, however, the one which is almost exclusively employed in trade and commerce in Great Britain, not only on account of its simplicity and correctness, but for the purpose of the results exactly coinciding with the results obtained by the Revenue officers.

1. Methods based on the specific gravity, or per-centage strength, by VOLUME:—

a. With Sykes’ Hydrometer. Revenue system. The engraving below represents Sykes’ hydrometer, as made by Mr Bate, under the directions of the Commissioners of Inland Revenue and Customs. It consists of a spherical ball or float, with an upper and lower stem, and is made of brass, which (in the more expensive instruments) is usually coated with gold, to prevent corrosion from damp, and the acidity so generally present in spirituous liquors. The upper stem (A) is about four inches long, and is divided into ten parts, each of which contains five subdivisions. There are nine movable weights of the form b, of different sizes, numbered respectively 10, 20, 30, &c., to 90, each of which represents so many of the principal divisions of the stem, as its number indicates. In use, one of these weights is slipped on to the lower stems; and thus, by means of them, the instrument acquires a range of above 500 divisions, or degrees, extending from the Revenue ‘standard alcohol’ (sp. gr. ·825) to water. It is so formed as to give the sp. gr. with almost perfect accuracy, at 62° Fahr. When loaded with the weight 60 it sinks in proof spirit to the line marked (P) on the narrow edge of the stem at 51° Fahr.; and, by further placing the square weight or cap (also supplied with the instr.) on the top of the upper stem, it floats exactly at the same point in distilled water. This weight or cap is found to weigh 43·66 grs., which is practically 1-12th of the total observed weight of the instrument, and its poise 60, and hence shows the difference between the gravity of proof spirit and water, as explained hereafter. The whole is fitted up in a neat mahogany case, accompanied with a thermometer, and a book of tables containing corrections for temperature, &c.—Process. A glass tube of the form of fig. B is filled to about the mark (a) with the sample for examination; the thermometer is then placed in the liquor, and stirred about for two or three63 minutes (observing not to breathe upon the glass, nor hold it in the hand), and the temperature noted. The hydrometer is next immersed in a similar manner, and gently pressed down in the liquor to the 0 on the stem with the finger; it having been previously loaded with any one of the nine weights that will cause it to float with the surface of the spirit at some point on the graduated part of the scale. The indication at the point cut by the surface of the liquor, as seen from below, added to the number of the weight with which the float is loaded, gives a number which must be sought in the hook of Tables, which is always sold with the instrument. In this book, at the page headed “Temperature as observed by the Thermometer,” and against the part of the column appropriated to the given indication (weight), will be found the strength per cent., expressed in degrees over or under proof, by VOLUME, in whole numbers or decimal parts. In reading off the indication, to ensure accuracy, it is necessary to allow for the convexity of the liquor at the part where it immediately rests against the stem.

Obs. In an instrument requiring so much care and skill in its manufacture the purchaser should be careful to procure a perfect one. A very slight blow, friction from continual wiping with a rough cloth, and other apparently trivial causes, tend to injure so delicate an instrument. The shape of the weights occasionally vary; some being intended to be attached to the hydrometer at the bottom of the spindle, and others to rest on its top. The first plan is, perhaps, the best, as it tends to make the instrument float with greater steadiness in the liquor; but, at the same time, it renders its adjustment by the maker a matter of greater difficulty.

In employing this instrument, the Revenue officers are instructed to take the nearest degree above the surface of the mercury, when it stands between any two degrees of the thermometer; and the division on the scale of the hydrometer next below the surface of the liquid, when it cuts the stem between any two lines; thus giving the difference in favour of the trader in both cases.

By means of the Table at page 64 the hydrometer indication, or the degrees over or under proof, of the Revenue system, may be converted into ‘real specific gravities,’ by mere inspection; and the corresponding ‘per-centage richness’ in alcohol of any sample may be found, either by WEIGHT or VOLUME.

The specific gravities in this table are such as, on being referred to Gilpin’s Tables, will give the expressions of proof strength answering to the whole indications of the Revenue hydrometer. Intermediate values at fifths of indications may be had by taking proportional differences between the nearest tabular numbers. Thus, to find the specific gravity that should stand opposite to Indication 70·6, we first obtain the difference between the densities standing in a line with Indications 70 and 71 respectively, and then say, as 1 : 0·6 :: ·00192. 00·115, and ·94135 + ·00115 = ·94250, the specific gravity required.

b. With GLASS ALCOHOLOMETERS. That of Tralles, and most others of a like description (as made in England), gave the per-centage strength, by VOLUME, with tolerable accuracy, at the standard temperature of 60° Fahr. Gay-Lussac’s ALCOÖMETRE, which closely resembles that of Tralles, is adjusted for the temperature of 59° Fahr. (15° Cent.). All of these, to give at once accurate results, must, of course, be employed at the ‘normal temperature’ of the instrument. As, however, in practice, the experiment cannot be conveniently performed at any ‘fixed’ temperature but only at that of the atmosphere, it is obvious that certain corrections are constantly required in order to obtain results of any value. Perfect accuracy requires that table for every variation of the thermometer, founded on actual experiments, should accompany each instrument; as, without them, tedious and difficult calculations are necessary, which, in the hurry of the cellar and laboratory, or by persons inexpert at figures, are not easily performed. A series of such Tables were prepared by Gay-Lussac, and, with his instrument, are those which are almost exclusively used in France. For rough purposes, in the absence of Tables or nicer calculations, it may be useful to know that, for commercial spirits, at ordinary temperatures, a variation of—

5°	Fahr.	is equal to (about)	1·00%	of Alcohol; or (about)	1·794%	of Proof spirit.
1°	”	”	0·20%	”	0·359%	”
5°	Cent.	”	1·80%	”	3·229%	”
1°	”	”	0·36%	”	0·646%	”

5°	Fahr.	is equal to (about)	0·80%	of Alcohol; or (about)	1·62%	”
1°	”	”	·16%	”	·32%	”
5°	Cent.	”	1·43%	”	2·9%	”
1°	”	”	·28%	”	·58%	”

Sykes’ Hydrometer Indication.	Strength per cent.	Specific Gravity.	Per Cents. of Absolute Alcohol.
			By Measure.	By Weight.
	O.P.
0	67·0	·81520	95·28	92·78
1	66·1	·81715	94·78	92·08
2	65·3	·81889	94·31	91·42
3	64·5	·82061	93·84	90·78
4	63·6	·82251	93·33	90·07
5	62·7	·82441	92·80	89·36
6	61·8	·82622	92·29	88·67
7	60·9	·82800	91·77	87·99
8	60·0	·82978	91·25	87·30
9	59·1	·83151	90·74	86·63
10	58·2	·83323	90·23	85·96
11	57·3	·83494	89·72	85·30
12	56·4	·83661	89·21	84·65
13	55·5	·83827	88·70	84·00
14	54·6	·83993	88·17	83·33
15	53·7	·84153	87·67	82·70
16	52·7	·84331	87·10	81·99
17	51·7	·84509	86·51	81·26
18	50·7	·84680	85·95	80·58
19	49·7	·84851	85·39	79·89
20	48·7	·85022	84·81	79·19
21	47·6	·85205	84·19	78·44
22	46·6	·85372	83·61	77·74
23	45·6	·85537	83·04	77·07
24	44·6	·85700	82·47	76·39
25	43·5	·85878	81·85	75·66
26	42·4	·86055	81·21	74·92
27	41·3	·86229	80·59	74·19
28	40·2	·86402	79·97	73·47
29	39·1	·86574	79·34	72·75
30	38·0	·86745	78·71	72·03
31	36·9	·86915	78·08	71·32
32	35·7	·87099	77·40	70·54
33	34·5	·87282	76·71	69·77
34	33·4	·87450	76·08	69·06
35	32·2	·87627	75·41	68·32
36	31·0	·87809	74·72	67·55
37	29·8	·87988	74·03	66·79
38	28·5	·88179	73·29	65·98
39	27·3	·88355	72·60	65·23
40	26·0	·88544	71·86	64·43
41	24·8	·88716	71·17	63·68
42	23·5	·88901	70·43	62·89
43	22·2	·89086	69·69	62·10
44	20·9	·89268	68·95	61·32
45	19·6	·89451	68·21	60·53
46	18·3	·89629	67·47	59·76
47	16·9	·89822	66·67	58·92
48	15·6	·89997	65·93	58·15
49	14·2	·90182	65·14	57·34
50	12·8	·90367	64·34	56·52
51	11·4	·90551	63·54	55·70
52	10·0	·90732	62·74	54·89
53	8·6	·90913	61·94	54·09
54	7·1	·91107	61·09	53·23
55	5·6	·91299	60·24	52·38
56	4·2	·91479	59·43	51·57
57	2·7	·91666	58·58	50·73
58	1·3	·91839	57·78	49·94
	U.P.
59	0·3	·92037	56·86	49·04
60	1·9	·92228	55·96	48·17
61	3·4	·92408	55·10	47·33
62	5·0	·92597	54·19	46·46
63	6·7	·92798	53·22	45·53
64	8·3	·92984	52·30	44·65
65	10·0	·93176	51·36	43·76
66	11·7	·93367	50·39	42·84
67	13·5	·93586	49·34	41·86
68	15·3	·93758	48·31	40·90
69	17·1	·93949	47·29	39·96
70	18·9	·94135	46·29	39·04
71	20·8	·94327	45·20	38·04
72	22·7	·94518	44·09	37·03
73	24·7	·94709	42·96	36·01
74	26·7	·94899	41·82	34·98
75	28·8	·95092	40·63	33·92
76	31·0	·95288	39·40	32·82
77	33·2	·95484	38·10	31·68
78	35·6	·95677	36·76	30·50
79	38·1	·95877	35·32	29·24
80	40·6	·96068	33·90	28·01
81	43·3	·96259	32·41	26·73
82	46·1	·96457	30·77	25·32
83	49·1	·96651	29·08	23·88
84	52·2	·96846	27·31	22·38
85	55·5	·97049	25·39	20·77
86	59·0	·97254	23·41	19·11
87	62·5	·97458	21·39	17·42
88	66·0	·97660	19·41	15·78
89	69·4	·97857	17·46	14·16
90	72·8	·98057	15·51	12·56
91	76·1	·98261	13·58	10·97
92	79·2	·98452	11·85	9·56
93	82·3	·98657	10·04	8·08
94	85·2	·98866	8·28	6·65
95	88·0	·99047	6·83	5·48
96	90·7	·99251	5·25	4·20
97	93·3	·99448	3·80	3·03
98	95·9	·99658	2·31	1·84
99	98·2	·99851	·997	·793
100	...	1·00000	...	...

This Table {above} has been copied, by permission, from Loftus’s ‘Inland Revenue Officer’s Manual,’ and its correctness verified by W. H. Johnston, Esq., Surveying General Examiner.65

Water taken as 1000.
Specific gravity.			Correction for each degree.	Specific gravity.			Correction for each degree.
810	to	820	± ·475	910	to	920	± ·434
820	”	830	± ·473	920	”	930	± ·424
830	”	840	± ·472	930	”	940	± ·406
840	”	850	± ·471	940	”	950	± ·381
850	”	860	± ·471	950	”	960	± ·340
860	”	870	± ·466	960	”	970	± ·269
870	”	880	± ·460	970	”	980	± ·165
880	”	890	± ·456	980	”	990	± ·090
890	”	900	± ·450	990	”	1000	± ·084
900	”	910	± ·442

Thus, by making the proper ADDITION to the apparent strength per cent., when the observed temperature is BELOW the normal temperature of the instrument, or a corresponding SUBTRACTION, when it is ABOVE it, the strength of the sample may be determined sufficiently near for all practical purposes.

The following Table, taken from Loftus’s ‘Inland Revenue Officer’s Manual,’ will be found of great value in making these corrections, and has the merit of being easily applied.

Example.—If a quantity of spirit is of the sp. gr. 894 at 73°, what will be its sp. gr. at 60°?

Here the sp. gr. being between 890 and 900, we must add ·450 for each degree of temperature between 73° and 60°. The sp. gr. at 60° would, therefore, be 894 + (·450 × 13) = 899·85. When the temperature is below 60°, the correction for each degree must be subtracted. When, however, very accurate results are desired, and the necessary Tables are not accessible, the sample for trial must be brought to the normal temperature of the instrument, in the manner explained under Hydrometry.

c. From the SPECIFIC GRAVITY. The temperature having been taken by a thermometer, and the specific gravity ascertained by any of the usual methods, but preferably by means of an accurate glass hydrometer, it merely becomes necessary to refer to Table I, where, against the number expressing the specific gravity, the alcoholic content per cent., by volume, of the sample examined, will be found for 60° Fahr., subject to the corrections just referred to, when the temperature is either above or below this point.

If the precise specific gravity sought cannot be found in the Table, the difference between it and the next greater specific gravity must be taken for the numerator of a fraction, having for its denominator the difference between the greater and the next less specific gravity in the table. This fraction, added to the per-centage of alcohol in the fourth column of the table, opposite the greater sp. gr., will give the true per-centage sought. Thus, the sp. gr. ·96051 is not in the table, and the next greater number is ·96068; the former must, therefore, be deducted from the latter, and the difference (17) put as the numerator of the fraction, having for its denominator 191, the difference between ·96068 and ·95877. The fraction (¹⁷⁄₁₉₁) ·089, so found, added to the per-centage strength opposite ·96068 in the third column, gives 33·989 as the true per-centage of alcohol in the given sample.

The per-centage by volume may be converted into per-centage by weight, by multiplying the former by ·793811, the sp. gr. of absolute alcohol, and dividing the product by the sp. gr. of the sample. The quotient is the number of pounds of alcohol in 100 pounds of the given spirit. Thus:—Suppose 1000 grains by measure of alcohol to weigh 950·92 grains, and to contain (see Table I) 40·63 per cent. by volume of absolute alcohol, what per cent. by weight does the sample contain?

·793811 × 40·63 = 32·25254093, and this product divided by ·95092 = 33·917, the true per-centage by weight of absolute alcohol in the sample.

The specific gravity is ascertained and the Table used in precisely the same manner as in the “method by volume,” already described.

The per-centage by weight may be converted into per-centage by volume, by multiplying the former by the sp. gr. of the sample, and dividing the product by the sp. gr. of absolute alcohol. This is merely the reverse of the operation described above.

Obs. The preceding methods of alcoholometry, as well as all others depending on the sp. gr. refer to UNSWEETENED SPIRITS only; and are inapplicable to those holding sugar in solution, or any other organic matter capable of altering the sp. gr. For sweetened spirits, fermented worts, wine, beer, &c., one or other of the following processes must be adopted:—

3. Other methods, adapted to either SWEETENED or UNSWEETENED SPIRITS, Tinctures, Fermented Liquors, &c.—

a. By DISTILLATION as originally proposed by M. Gay-Lussac. 300 parts of the liquor under examination (measured in a graduated glass tube) are placed in a retort or small still, and a quantity exactly equal to one third (i.e., 100 parts), carefully drawn over; a graduated glass tube [13] being used as a receiver, and66 the operation stopped as soon as the distillate reaches the hundredth degree. The ‘alcoholic strength’ of the distilled liquor is then ascertained by any of the usual methods, and the result divided by three, when the per-centage of alcohol in the original liquor is at once obtained. If, from want of attention, more than 100 parts should be distilled over, the number which expresses the relation of the volume of the distilled product to the original bulk of the liquor tested, must be employed as the divisor. Thus, if 106 parts of liquor have distilled over (instead of 100), containing 33% of alcohol, the 300 must be divided by 106, which gives 2·83, and the 33% by this 2·83, which gives 11·66%, the true proportion of alcohol in the original liquor. The strength at ‘proof’ may be calculated from this in the usual way.

To ensure accurate results, the acidity (if any) of the liquor must be neutralised with carbonate of sodium, prior to distillation. It is also advisable to add 8% or 10% of common salt to the liquor in the retort or still; this, by raising the boiling point, causes the whole of the spirit to pass over into the receiver before the distillate has reached the required measure. This applies more particularly to weak liquors. With those of greater strength (as the stronger wines), it is better to distil over 150 parts, and divide the result by 2 instead of 3. To liquors stronger than 25% by volume of alcohol, or above 52% to 54% under proof, add about an equal volume of water to the liquor in the still, and draw over a quantity equal to that of the sample tested; when the alcoholic strength of the distillate gives, without calculation, the true strength sought. To liquors stronger than 48% to 50% (14 to 12 u. p.), add thrice their bulk of water, and do not stop the process until the volume of the distillate is double that of the sample tested, when the per-centage obtained must also be doubled. In each case a proportionate quantity of salt is employed.

Revenue Method. The following is the method adopted in the Inland Revenue and Customs Laboratories for the estimation of the per-centage of alcohol in wines, liqueurs, &c. A measure flask is filled up to a mark on its neck, with the wine, which is then carefully transferred to a distilling flask or retort, the traces of wine remaining in the former vessel being rinsed out with small quantities of distilled water, and the rinsings added to the wine in the latter vessel. About two thirds of the contents of the retort are then distilled over into the clean measure flask, and made up to the original bulk with distilled water, at the same temperature as the sample was previous to distillation. The strength is then taken by Sykes’ hydrometer, and this (if u. p.) deducted from 100, gives the per-centage of proof spirit in the wine. Thus:—

Strength of distillate = 74·6 u. p. = 25·4 per cent. proof spirit.

b. From the Temperature of the Vapour, as originally proposed by Gröning. The bulb of a thermometer is thrust through a cork into the head of the still, or other vessel employed, and the temperature of the vapour in which it is immersed being noted, is sought in the following table:—

Temperature of the Vapour. Fahr.	Alcoholic content of the Distillate per cent.	Alcoholic content of the Boiling Liquid per cent.	Temperature of the Vapour. Fahr.	Alcoholic content of the Distillate per cent.	Alcoholic content of the Boiling Liquid per cent.
170·0	93	92	189·8	71	20
171·8	92	90	192·0	68	18
172·0	91	85	194·0	66	15
172·8	90¹⁄₂	80	196·4	61	12
174·0	90	75	198·6	55	10
174·6	89	70	201·0	50	7
176·0	87	65	203·0	42	5
178·3	85	50	205·4	36	3
180·8	82	40	207·7	28	2
183·0	80	35	210·0	13	1
185·0	78	30	212·0	0	0

This method is admirably adapted to the purposes of the distiller and rectifier, as it furnishes a ready means of approximately determining the strength of the spirit passing over, at every part of the process of distillation, as well as that of the wash left in the still.

c. From the BOILING POINT, as originally proposed by M. l’Abbé Brossard-Vidal. This method is founded on the fact, that the boiling points of mixtures of alcohol and water, unlike water alone, are scarcely disturbed by the addition of saline, saccharine, or extractive matter within certain limits. It hence offers a ready means of determining the proportion of alcohol present in spirits, wines, fermented67 liquors, &c., with sufficient accuracy for all ordinary purposes. In applying it, a thermometer, with a large bulb and a narrow bore, and a movable scale graduated from 180° to 212° Fahr., is usually employed. Before using it as an alcoholometer, it is set, with its bulb immersed, in a small metallic boiler (brass or copper) containing distilled water, which is then raised to the boiling-point, and the 212° of the scale accurately adjusted on a level with the surface of the mercury, should it vary from that point. This is necessary on account of variations of atmospheric pressure causing corresponding variations of the boiling-points of liquids. It is then ready for several hours’ operations, and, generally, for an entire business day, without further adjustment. The little boiler is next filled with the liquor to be examined, and the lamp again lighted. The temperature as shown by the scale of the instrument at the commencement of full ebullition being ascertained, may be sought in one of the following Tables, against which the alcoholic content of the liquor will be found (nearly).

Boiling point. Fahr.	Alcohol per cent. by volume.	Boiling point. Fahr.	Alcohol per cent. by volume.
205·34	5	179·96	55
199·22	10	179·42	60
195·8	15	178·7	65
192·38	20	177·62	70
189·50	25	176·54	75
187·16	30	175·46	80
185·	35	174·92	85
183·38	40	174·2	90
182·12	45	173·14	95
181·58	50	172·	100

Boiling points. Fahr.	Per-centage strength.		Corresponding Sp. Gr.

178·5	Proof.		·9200
179·75	10·	U.P.	·9321
180·4	20·	”	·9420
182·1	30·	”	·9516
183·4	40·	”	·9600
185·6	50·	”	·9665
189·	60·	”	·9729
191·8	70·	”	·9786
196·4	80·	”	·9850
202·	90·	”	·9920

Obs. This method does not answer well with spiritous liquor above ‘proof,’ owing to the variations of their boiling point being so slight as not to be easily observed with accuracy; but with liquors under ‘proof,’ and particularly with wines, beer, and other fermented liquors, due care being observed, it gives results closely approximating to those obtained by distillation, and sufficiently accurate for all ordinary purposes. In testing strong alcoholic solutions it is, therefore, proper to dilute them with twice their bulk of water; and commercial spirits, with an equal bulk of water; the results obtained being doubled or tripled as the case may be.

d. From the EXPANSION of the LIQUID when heated: Silbermann’s DILATATOMETER. The expansion of alcohol between 0° and 212° Fahr. is triple that of water; and between 77° and 122° Fahr. it is much greater. Between -14° and -98° Fahr. the rate of expansion is about the ·00047th part in volume for every degree of Fahrenheit’s scale. The measurement of this expansion has been proposed as a new and ready method of alcoholometry, adapted to nearly all spirituous and fermented liquors. Silbermann’s instrument, which is based on it (see engr.), simply consists of a flat brass or ivory plate (A), on which are fixed a mercurial thermometer (D) graduated from 22° to 50° Cent. (= 77° to 122° Fahr.); and the DILATATOMETER (B), which is a glass pipette open at both ends. A valve of cork, or vulcanised india rubber, closes the tapering end (c); this valve is attached to a movable rod (C) which is fastened to the supporting-plate, and connected with a spring68 (f) and a handle (g) bearing a four-threaded screw, by which the lower orifice of the pipette can be opened or closed at will. In use, the pipette is filled with the liquor under examination, to a little above the zero point (0) on the scale. This is effected by suction, by means of a little piston of leather (i), which fits tightly in the long and wider limb of the pipette; the valve (d) being previously opened by turning the knob (h). The proper quantity of liquor being introduced, and the lower end closed, the piston is moved up and down two or three times, for the purpose of drawing the air-bubbles and absorbed air out of the liquid, the presence of which would vitiate the results of the trial. To allow the piston to be withdrawn without any shock, or the danger of dividing the column abruptly, the rod attached to it is made hollow throughout. In using it the operator applies the ball of his forefinger to the top of the piston-rod (E), in order to create a vacuum as he raises it; and then withdraws it, to readmit the air when he thrusts it down or removes it from the tube. The excess of liquid (if any) in the pipette is then run off until its upper surface is exactly level with the zero (0) of the scale, at 25° C., to which it is raised by immersion in a water bath of that temperature, as observed by the thermometer; which is done by very cautiously turning the rod which depresses the valve. The whole apparatus is now again immersed in the water bath; and, held by the upper portion of the plate, kept in gentle motion with the hand, until the temperature rises to exactly 50° C., when the coefficient of expansion is obtained, and hence also the proportion of alcohol—the scale of the instrument being so graduated, from actual experiments previously made upon mixtures of known composition, as to give, at once, the per-centage of alcohol by VOLUME (nearly).[14]

e. From the TENSION of the VAPOUR:—Geissler’s ALCOHOLOMETER. This method, for which we are indebted to M. Geissler, of Bonn, depends on the measurement of the tension or elastic force of the vapour of the liquid, as indicated by the height to which it raises a small column of mercury. The spirit, wine, or other liquor, of which it is desired to ascertain the strength, is put into the little flask (a), which, when completely filled, is screwed on to the curved glass-tube which contains the mercurial column (which is inverted for the purpose), and is closed by the stop-cock (b). The instrument (see engr.) is then placed erect, and the flask and lower part of the tube immersed in a water bath, as in the previous method. The number, on the graduated scale of the instrument corresponding to the height of the mercury, at the boiling point of the liquor under examination, gives the per-centage of alcohol by VOLUME (nearly).

This method furnishes approximative results with great facility and expedition; and, with proper care, these do not vary more than ¹⁄₃ to ¹⁄₂ of 1%, from those obtained by distillation. We find, that by having the diameter of the part of the tube at which the surface of the mercury is acted on by the vapour a little larger than that of the longer limb, and by previously abstracting the air from the sample, as in Silbermann’s method, or even by agitation and exposure in an open vessel, the two may be made to correspond almost exactly.

f. From the DIFFERENCE between the sp. gr. BEFORE and AFTER ebullitiom:—Taberié’s method and ŒNOMETER. The sp. gr. of the sample is first accurately determined by any of the usual methods. It is next carefully evaporated, in an open vessel, to one half its volume. The residuum, when cold, is made up with pure water to exactly its original measure at its original temperature, and the sp. gr. again ascertained. The difference between the two being due to the spirit originally present, furnishes the means of calculating a new sp. gr., from which the per-centage richness of the sample may be obtained by mere inspection of the Tables. The observed sp. gr. is the true one, whenever the liquor, after ebullition and restoration to its original volume, has the same sp. gr. as water (i. e., 1·000), at 60° Fahr. Taberié employs a peculiar instrument, which he calls an œnometer; but its use is not essential to his method of alcoholometry. The results are, of course, only approximative, though sufficient for all ordinary purposes. Prof. Mulder, however, says that he prefers it to any of the previous methods; and that the results, with care, are almost as accurate as those obtained by distillation.

g. a. (Brande’s Method.) The liquor for trial is poured into a long, narrow glass tube (graduated centesimally), until the vessel is half-filled, and, after the solution of about 12% or 15% of a strong solution of subacetate of lead, or a little finely powdered litharge, is agitated until the colour is entirely, or nearly removed. Anhydrous carbonate of potash, in powder, is next added, until it sinks undissolved, even after prolonged agitation of the liquid. The whole is now allowed to repose for a short time, when the alcohol is seen floating on the top of the aqueous portion of the liquid in a well-marked stratum. Its quantity, read off by means of the graduations of the tube, and doubled, gives the per-centage richness of the sample in alcohol, by volume.

This process answers well with cordials, wines, and the stronger ales; but with very weak liquors it is not to be relied on. The69 whole operation may be performed in two to five minutes, and (with these exceptions) furnishes very reliable approximative results. In most cases the decolouring part of the process may be omitted. The alcohol thus separated has a sp. gr. of from ·8061 to ·8118, and contains 3% or 4% of water; but for ordinary purposes it may be regarded as pure alcohol.

4. Alcoholometry of MINUTE QUANTITIES of liquid. When only a few drops, or a quantity too small for the application of the preceding methods, can be obtained, an organic analysis may be had recourse to, and the quantity of absolute alcohol calculated from that of the resulting carbonic anhydride and water; care being previously taken to free the sample from other volatile bodies, if it contains any of them.

Gen. commentary. The duties on spirits in England are charged on the number of proof gallons they contain, which is ascertained by gauging or weighing the spirit, and then trying its strength by Sykes’ hydrometer. The per-centage of proof spirit multiplied by the number of gallons gives the net amount of proof spirit to be charged.

‘Proof strength’ is an arbitrary standard, adopted for the purpose of facilitating calculations, for which it is well suited; although pure alcohol would, for this purpose, be more simple. As defined by Act of Parliament, 58 Geo. III, c. 28, “proof spirit” is such “as shall, at the temperature of 51° of Fahrenheit’s thermometer, weigh exactly twelve thirteenth parts of an equal measure of distilled water.”

Taking, therefore, water at 51° Fahr. as unity, the sp. gr. of “proof spirit” at 51° Fahr. is ¹²⁄₁₃ of 1·000 or ·92308. When such spirit is raised to the temperature of 60° Fahr., its density is ·91984.

Spirit at “proof” contains very nearly equal weights of absolute alcohol and water; the exact proportions according to recent experiments are:—

By Weight.	By Volume.		Sp. gr. at 60° Fahr.
By Weight.	Bulk before admixture.	Bulk after admixture and condensation.	Sp. gr. at 60° Fahr.
Alcohol. Water.	Alcohol. Water.
100·00 + 103·08	100·00 + 81·80	175·23	·91984
49·24 + 50·76	57·06 + 46·68	100·00	·91984

The standard alcohol of the Revenue authorities, and that on which Gilpin’s Tables are founded, is a spirit of the sp. gr. ·825 at 60° Fahr., which is said to contain, by weight, 89% of pure alcohol of ·796; and 92·6% of alcohol, by volume, which corresponds to about 62·5 o. p.

It is of great importance to the spirit dealer to be able to estimate correctly the number of ‘proof gallons’ in any quantity of his commodities, or in the whole or any portion of his stock, as disagreeable errors frequently result from ignorance on this point. Calculations of this kind are extremely simple. Thus, when we find, by the hydrometer, that a given sample of spirit is 10 per cent. over-proof, it means, that 100 gallons of such spirit contain as much alcohol as 110 gallons of proof spirit.

In over-proof spirit, the per-centage o. p. always represents the quantity of water which the given spirit requires to reduce it to proof. By adding this per-centage over-proof to 100, we obtain a number which, multiplied by any number of gallons, and divided by 100, gives the exact number of proof gallons which is contained in any quantity of the spirit referred to. Thus:—A puncheon of rum gauged at 91 galls., and shown by the hydrometer to be 21 o. p., contains—

21 o. p. of sample added to 100	121
No. of gallons of rum	91
	———
	11011

No. of gal. of proof-spirit = 11011 / 100 = 110·11

In like manner when a spirit is said to be 11 u. p., or under-proof, it means that 100 gal. of such spirit contains 11 gal. of water, and 89 gal. of ‘proof spirit.’ By deducting the per-centage under-proof from 100, we not only obtain the number of proof gal. contained in 100 gal. of such spirit, but, as in the last case, a factor which multiplied by any number of gal., and divided by 100, gives the exact number of ‘proof gallons’ contained in any quantity of the given strength. Thus:—An ullage brandy piece containing 45 gal. of spirit at 10 u. p., would have the proof value of—

Per cent. u. p. of sample 10, subtracted from 100	90
No. of gall	45
	———
	4050

Quantity of proof spirit = 4050 / 100 = 40·50

The strength of absolute alcohol (sp. gr. ·7938) is estimated at 75¹⁄₄% over-proof. It therefore contains 175¹⁄₄% of ‘proof spirit,’70 whilst proof spirit (sp. gr. ·91984) contains 57·06% of ‘absolute alcohol,’ both being by measure or volume. Thus—

(meas. of alc. × 175¹⁄₄) / 100 = equiv. meas. of pf. spt.

(meas. of pf. spt. × 57·06) / 100 = equiv. meas. of abs. alc.

From which we derive the ‘constant multipliers’ 1·7525 (or roughly 1³⁄₄), and ·5706, applicable to any number of volumes or gallons. For—

meas. of alc. × 1·7525 = equiv. meas. of pf. spt.

meas. of pt. spt. × ·5706 = equiv. meas. of alc.

To ascertain what quantity of a spirit at any given strength is equiv. to or contains 100 lbs. of absolute alcohol, we have only to divide the constant number 2207·7 by the proof value per cent. of such spirit.[15] Thus—for a spirit 12 u. p.—this would be

100 - 12 = 88% of proof spirit;

2207·7 / 88 = 25·1 gal. (nearly).

That is, 25¹⁄₁₀ gal. of such spirit would contain 100 lbs. of absolute alcohol.

By removing the decimal point one place to the right, we have the equiv. measure of 1000 lbs. By removing it one, two, or three places to the left, we have it respectively for 10 lbs., 1 lb., and ¹⁄₁₀ lb.; from which the equiv. for all other weights may be easily obtained.

By reversing the above operation, the measure of alcohol corresponding to any given weight of spirit, at any strength, may also be easily found.

The weight of 1 gal. of absolute alcohol being 7·938 lbs.; that of 1 gal. of proof spirit, 9·2 lbs,; and that of the ‘alcohol’ in 1 gal. of proof spirit, 4·53 lbs.; the weight of any number of gallons or volumes of either, and their equivalents, may be easily found. Thus:—

gallons of alc. × 7·938	=	lbs. weight of alc.
gallons pf. sp. × 9·2	=	lbs. w. of pf. spt.

gallons	of alc. × 16·121	=	lbs. weight of pf. spt.
”	pf. spt. × 4·53	=	content in lbs. weight of alc.

In these cases a knowledge of the first four rules of decimal fractions is necessary, or, at least, advantageous; as the Excise officers carry their calculations to two figures of decimals, or ¹⁄₁₀₀ths. Their plan is to reject the third decimal figure when less than 5; but to carry 1 to the next figure on the left hand, when it exceeds 5. Thus, 5·432 is set down as only 5·43; but 5·437 is written 5·44. In the delicate chemical processes of the laboratory, even greater accuracy is observed.

Formerly, spirit was said to be 1 to 3, 1 to 4, &c., over-proof, by which it was meant that 1 gal. of water added to 3 or 4 gals. of such spirit would reduce it to ‘proof.’ On the other hand, 1 in 5, or 1 in 8, under-proof, meant that the 5 or 8 gals., as the case might be, contained 1 gal. of water, and the remainder represented the quantity of ‘proof spirit.’ This method of calculation has now long given way to the ‘centigrade system,’ which not only admits of greater accuracy, but is quite as simple. It should be adopted by every spirit-dealer in England, from being that which is employed by the Revenue officers, whose ‘surveys’ it is absolutely necessary that the trader should understand, in order that his own estimation of his stock and his business calculations should correspond with theirs.

Several other methods of alcoholometry, besides those already noticed, have been adopted at various times, but the majority of them possess so little accuracy as to be quite inapplicable to the purposes of trade, and of the laboratory. Thus, the strength was at one time estimated by what was called the ‘proof.’ A little of the spirit was poured upon a small quantity of gunpowder, contained in a spoon or saucer, so as just to moisten it, and was then inflamed. If at the end of the combustion the gunpowder took fire, the spirit was held to be ‘above proof,’ if it only languidly fizzed away, or slowly burnt, the spirit was said to be ‘proof,’ but if the gunpowder failed to ignite, the spirit was esteemed ‘below proof.’ Hence arose the terms ‘proof’ and ‘proof spirit,’ which have since been adopted by Act of Parliament. Another method was that of dropping oil into the spirit; if the oil floated, the spirit was considered to be ‘under proof,’ if it sunk, it was rated as ‘proof’ or ‘over-proof.’ The ‘gunpowder test’ is quite fallacious; for, if a certain quantity of a spirit is capable of firing the gunpowder, a little excess of a spirit 20% or 25% stronger will often fail to do so, so much water being formed as to prevent the ignition. The ‘Preuve d’Holland’ test, of the French, or the ‘BEAD,’ is still frequently employed by persons unacquainted with the use of the hydrometer. It consists in shaking the spirit in a phial, and observing the size, number, and duration of the bubbles or beads, as they are called. The larger and more numerous these are, and the more rapidly they break and disappear, the stronger the spirit is presumed to be. This method is unreliable, as the presence of sugar or acid, even in minute quantities, will sometimes give to a weak sample the appearance of one many degrees stronger. Lovi’s beads are also often employed to ascertain approximately71 the strength of spirit, when a hydrometer is not at hand.

The insufficiency of most of the methods of alcoholometry here referred to, throws us back on the Revenue System (Sykes’ hydrometer), or on the specific gravity for unsweetened spirits. For sweetened spirits, as cordials, wines, beers, &c., there are none of the tests which give such accurate results as the distillation test, previously described as the Revenue Method.

The spirituous liquors of commerce being sold by measure, and not by weight, the methods of alcoholometry which give the results, per cent., by volume, are those we have chiefly explained. In the laboratory, the method by weight is that most generally employed in delicate processes and in analyses. By weight, the per-centage of alcohol remains the same for all temperatures, for the same sample; whilst by volume, the per-centage varies with the temperature of the liquid. This variation explains the cause of many of the sudden apparent decreases and increases, which occur in large stocks of spirits. Persons purchasing spirits during very warm weather, and paying for them according to their apparent quantity and strength, lose considerably by selling the same spirit when the weather becomes colder, without being conscious of such loss from the hydrometer. The reason of this is obvious, for, whilst the relative proportions of the alcohol to the water continue the same, the sp. gr. and the volume alter with the temperature; the latter being increased by warmth, and decreased by cold, in exact opposition to the former. Accuracy requires, in all cases, that a spirituous liquor should be tested for its strength at the temperature at which it was measured; and measured at the same temperature at which its strength was determined.

A consideration of these facts has led some of the great houses to introduce the system of weighing their spirits, instead of measuring them, the weight of an imperial gallon at 60° Fahr. being taken as the standard gallon. This is the method adopted by the Inland Revenue, at all distilleries, for assessing the duty, and will be readily understood by the following example:—

		Cwts.	qrs.	lbs.
Gross weight of full cask	=	13	2	27
Tare	=	2	2	5
		——	——	——
Net weight of spirit	=	11	0	22

or 1254 lbs. Let us suppose the hydrometer indication to be 43·0, the weight per imperial gallon would be 8·903 lbs. (see Table VI), and 1254 ÷ 8·903 = 140 gallons.

⁂ For further information in connection with Alchoholometry see Alcohol, Beer, Brewing, Distillation, Ebullioscope, Hydrometer, Hydrometry, Liqueurs, Malt-Liquors, Organic Substances, Saccharine, Specific Gravity, Spirit, Sugar, Syrups, Tinctures, Wine, Wort, &c. 73&c.

ALCOHOL; EFFECTS OF ALCOHOLISM. Without entering into the controversy as to whether the moderate consumption of alcohol, or its total disuse, is the more conducive to personal health and comfort—whether, as Dr Anstie and others have asserted it acts, when prudently taken, as a food—or whether, as other medical authorities contend, even its moderate use is a disturbing factor in the human economy—there need be no qualification of the assertion, that when the drinking of spirituous liquids of any kind is indulged in to excess, the habit, if persisted in, must sooner or later terminate in impaired health, serious disease, and premature death.

A powerful array of facts could be brought in support of this statement. For instance, in Nelson’s statistics we find it mentioned that—

A temperate person’s chance of living is—					An intemperate person’s chance of living is—
At	20	=	44·2	years.	At	20	=	15·6	years.
”	30	=	36·5	”	”	30	=	13·8	”
”	40	=	28·8	”	”	40	=	11·6	”
”	50	=	21·25	”	”	50	=	10·8	”
”	60	=	14·285	”	”	60	=	8·9	”

The average duration of life after the commencement of habits of intemperance is—

Among	mechanics, working and labouring men	18	years.
”	traders, dealers, and merchants	17	”
”	professional men and gentlemen	15	”
”	females	14	”

Again, Dr Dickinson, writing “on the morbid effects of alcohol in persons who trade in liquor,” gave the results of an examination of 149 traders in liquor, as compared with 149 persons of various trades. The general results were diseases of the liver much more common in those who dealt in alcoholic drinks. In the lungs tubercle affected sixty-one persons of the alcoholic, forty-four of the non-alcoholic.

Tubercle in the brain, liver, kidneys, spleen, bowels, mesenteric glands, and peritoneum were twice as common in the alcoholic as in the non-alcoholic. The verdict, therefore, is unavoidable that alcohol (in excess) engenders tubercle in the brain, inflammations, atrophy, hæmorrhages; in the heart and vessels atheroma, hypertrophy, and other affections, were all more common in the alcoholic than in the non-alcoholic series. The evidence in kidney disease did not appear so conclusive, but some forms of kidney disease appear to be increased. The author sums up thus:—“Alcohol causes fatty infiltration and fibroid encroachment; it engenders tubercle, encourages suppuration, and retards healing; it produces untimely atheroma, invites hæmorrhage, and anticipates age. The most constant fatty change, replacement by oil of the material of epithelial cells and muscular fibres, though probably nearly universal, is most noticeable in the liver, the heart, and the kidney.”

Alcohol also seems to be the cause of special diseases, besides those more common and generally known ones, delirium tremens, alcoholism, &c. Of these we may mention one recorded by M. Galezowski, a peculiar affection of the eyes, which the doctor found very74 prevalent during the siege of Paris in 1870-1. In the five months of the siege fifty patients were affected by it, whilst during the twelve months preceding the siege only nineteen were to be found. Dr Galowski ascribed the malady to the habit of taking alcoholic drinks in the morning fasting. A peculiar kind of palsy has also been referred to alcoholic poisoning.

The following table, compiled by Dr Joseph Williams, lends support to the fact that an indulgence in alcohol is either the cause of insanity, or that it tends to its increase:

	Total admission.	Proportion caused by intemperance.
Charenton	855	134
Bicêtre and Salpêtrière	2012	414
Bordeaux	156	20
Turin, 1830-31	158	17
Turin, 1831-36	390	76
Gard	209	4
United States	551	146
Palermo	189	9
Caen	60	16
Dundee	14	4
M. Parchappe	167	46
M. Batten	288	54
	———	———
	5019	940

Commenting on these figures, Mr Walter Blyth remarks, “There may be another explanation of the fact that many mad people have been great drinkers. A large proportion of those subject to insanity are driven by their morbid minds to drink; so that it may be that insanity causes drink, and not drink causes insanity.”

Many medical writers who are no advocates for the total abandonment of alcohol limit its consumption, in healthy people, to one or two fluid ounces a day, in the form of wine, beer, or spirits and water; two fluid ounces is, we believe, the quantity apportioned daily to every able-bodied seaman in the Royal Navy. Any slight habitual departure from this standard—even when the evidences of excess are not perceptible to others—all authority, historical, pathological, and physiological (unless it be given as a medicine), shows to be injurious. The researches of Anstie, Parkes, and Count Wollowicz, appear to prove that any quantity of alcohol exceeding an ounce and a half taken by an adult showed itself in the urine, a circumstance which these writers look upon as tending to show that the system has taken more alcohol than can be used in the body itself. In slight doses the action of alcohol is to produce a sedative effect upon the nerves, to redden slightly the lining membrane of the stomach, and to stimulate the secretion of the gastric juice.

Thus, in small doses alcohol may, and doubtless does, promote appetite. In excess, however, all these effects are turned to evil, and then ensue an inflammatory condition of the stomach, compression of the gland ducts from thickening of the tissue around them, excessive mucous secretion, and great loss of appetite. When carried into the circulation it greatly increases the force of the heart’s action, and at the same time paralyses, as it were, the restraining nervous supply to the arteries and small vessels, so that they can no longer oppose themselves to the blood-current, but dilate. This action in a small degree, occurring in persons of a weak and languid circulation, is no doubt beneficial; on the other hand, when in excess, it is most dangerous, and is a cause of the greater part of the diseases of the heart and great vessels.

“There appears to be a slight fall of temperature with moderate doses of alcohol, a very decided fall with excessive doses; the muscular and nervous systems are transitorily stimulated, and may do more work when small doses are given in cases of fatigue, but in other cases there is a marked torpor of the nervous and a want of co-ordination of the muscular system.”—Blyth.

Notwithstanding the researches of Percy, Strauch, Masing, Lallemand, Duroy, Parkes, Dupré, Anstie, Thudichum, and others, there is still a considerable divergence of opinion as to how alcohol is eliminated from the body. By some of the authorities just named it is affirmed to be eliminated as aldehyd, by others as carbonic acid; as to the latter, the experiments of Dr E. Smith show that the carbonic acid is decreased when brandy and gin are drunk, and increased by rum.

The only probable supposition, which facts support, tends to show that the alcohol is turned into acetic acid in the body, some of which unites with potash and other bases, and some is destroyed. All are pretty well agreed that in the form of spirits alcohol as a food is valueless, but that in the form of beer and wine it is possessed of a slight dietetic power, naturally varying with the amount and nature of the different substances held in solution in these beverages.

The imports of spirits into this country, in the seven years from 1850 to 1857, amounted to 70,740,980 gallons; whilst the imports in the seven years following, viz. from 1857 to 1864, were 78,016,071 gallons, showing an increase of 7,305,091 gallons. The population has, however, increased in the time, and a deduction on that account, as well as correction on one or two other heads, are required; still, that there is an increase is indisputable.

As respects France, a considerable increase in the consumption of spirits has taken place of late years, as the following table by M. Husson will illustrate:75

				Litres.		Litres.
From	1825	to	1830	8·96	yearly.	·024	daily.
”	1831	”	1835	8·74	”	·023	”
”	1836	”	1840	10·15	”	·026	”
”	1841	”	1845	11·14	”	·031	”
”	1846	”	1850	11·03	”	·030	”
”	1851	”	1854	14·25	”	·039	”

In the United States, during the period from 1807 to 1828, the average was 27 litres for every inhabitant, which is even greater than the highest of the two sets of figures just quoted.

The demoralisation of the French army during the late Franco-Prussian war has been also unanimously ascribed to the excessive consumption of spirituous liquids.

The following results of an inquiry instituted in 1870 by the Massachusetts Board of Health into the comparative sobriety of different nations are gathered from an able paper which appeared in the ‘Medical Times and Gazette’ of April 15th, 1872, by Dr Druitt, in which he dissects and summarises the results in question. Dr Druitt writes:

“Highest in the scale of temperance come the Turks and Arabs; next the Iberians, Levantines, Greeks, and Latin races; lower down the Japanese, Scandinavians, Belgians, and the Irish Celt; lowest of all the so-called Anglo-Saxon of either continent.”

Professor Levi contributes to our knowledge on this subject by giving the following statistics:—In 1860 the committals for drunkenness in England and Wales were 88,000, and in 1870 134,000, an increase of 50 per cent.

In Manchester the increase from 1860 to 1870 was 375 per cent., or computed according to the increase of population 35·3 per cent. In London drunkenness is in the proportion of 5·43 per 1000, in Leeds 7·40, in Manchester 31·13, and in Liverpool 42·82. It must, however, be remembered that these figures are based on mere committals, which greatly depend on the activity of the police, and the noisy or quiet character of the drunkard.

We quote the following from Dr Blyth’s work on ‘Hygiene,’ without, however, attempting either to endorse or controvert what he says on the subject.

“Whether is Alcohol necessary or not. All experience, both at home and abroad, shows by facts that cannot be disputed that a person can do quite as hard work without alcohol as with it; and probably as the limits between moderation and excess are easily passed, and as the generality of mankind, even without intending it, err on the latter side, the result is that a comparison between total abstainers and even temperate men generally terminates in favour of the former. It would appear that total abstainers live longer, are better citizens, and can do more work than the rest of mankind. The figures of the “United Kingdom Temperance and General Provident Institution” go far to prove the above. This insurance society is divided into two sections. One section consists of abstainers, the other of persons selected as not known to be intemperate. The claims for five years anticipated in the temperance section were £100,446, but the actual claims were only £72,676. In the general section of the anticipated claims were £196,352; the actual claims no less than £330,297. In war the march of 2000 miles in his War of Independence by Cornwallis and his troops (1783), the Maroon war of Jamaica, the 400 miles’ march of an English army across the Desert from Komer, on the Red Sea, a march of 1000 miles in the Kaffir war, experiences at sieges, in action, in hot, temperate, and cold climates, where abstinence was either forced through circumstances or followed, shows to every unprejudiced mind that soldiers endure more fatigue, are healthier, and fight better, without stimulants than with them; and this fact is endorsed by every commander of the present day.

The excess and abuse of spirits, as before remarked, lost the French their military prestige in the Franco-German war. In very hot and very cold climates the Indian observers and the Arctic explorers all unite in condemning its (that is, the use of alcohol) use in the slightest excess, or even in moderate doses. It does not warm the body in cold climates, and the reaction that follows the exciting of the circulation is followed by a dangerous depression; whilst in hot it combines with the climate, and quickly produces disease.”

ALCOHOLIC DRINKS, EFFECTS OF. In addition to the serious injury to health caused by an excessive or imprudent indulgence in spirituous stimulants (see previous article), even a moderate and not injudicious use of them may often be attended with very disagreeable consequences—a more or less mild or modified form of poisoning, in fact—if the beverages themselves are, as very frequently happens, contaminated, either accidentally or intentionally, with certain objectionable ingredients. These ingredients are described under the articles Beer, Wines, and the various SPIRITS, such as Gin, Brandy, Absinthe, &c. Of spirit drinking it may be observed, that this dangerous practice is intensified by what is to be feared is the too prevalent custom of taking them undiluted, or “neat,” as it is termed. There is no doubt that they constitute the very worst form of alcoholic drinks, and shorten the lives of those who indulge in them to excess more summarily than any other intoxicating potion. The greatest and most ineradicable drunkards are almost always found to be spirit drinkers.

Liebig remarked that less bread was consumed in families where beer was drunk, and there seems to be little doubt that the different species of beer, including porter and ale, when76 pure and free from adulteration, act, although in a small degree, as food. Probably there are some who will agree with, whilst others will dissent from, Benjamin Franklin, who said “there was more sustenance in a penny loaf than in a gallon of beer.” The starchy extractive matters of the beer no doubt perform the same function in the animal economy that sugar does. It is well known that those who drink freely of beer mostly become corpulent, as witness the portly forms of draymen. The hop contained in the beer has doubtless tonic and stomachic qualities. We can speak with less certainty about the free acids contained in malt fluids. It is very certain that some people cannot drink a glass of beer without experiencing rheumatic pains in the joints, which effect is generally ascribed to the acidity of the beer; but which is really supposed to be due to the decreased elimination of urea and pulmonary carbonic acid from the system caused by the alcohol of the beer.

The heavy low-priced beers occasion drunkenness of a peculiarly violent and savage kind, a fact which strongly favours the inference that this form of intoxication is due to some toxic agent, used as an adulterant. Of wines, the clarets and subacid wines are undoubtedly antiscorbutic in properties, and light wines as beverages are preferable to the stronger. Port, sherry, beer, stout, and ale are almost universally condemned in cases where there is a tendency to gout. The light clarets and Rhine wines are far more desirable beverages when this is the case, and the German wines are said to be valuable drinks in many lithic affections. It seems probable that the ethers and the vegetable salts, together with the sugar contained in wines, perform the most important part in the human economy.

It has been proposed to introduce the red subacid wines as drinks for our sailors, because of their antiscorbutic qualities. Some of the alcoholic drinks prepared in India frequently cause temporary madness.

AL′COHOLS. In chemistry, a term applied to compounds possessing a composition, formulæ, and chemical properties similar to those of ordinary alcohol. They form a series presenting an unmistakable symmetry, and differ from one another by well-marked gradations, as shown below:—

Methyl-alcohol (wood spirit).	CH₄O
Ethyl-alcohol (ordinary alcohol)	C₂H₆O
Amyl-alcohol (füsel-oil)	C₅H₁₂O
Capryl-alcohol	C₈H₁₈O
Cetyl-alcohol	C₁₆H₃₄O
&c., &c.

Alcohols. In commerce, pure spirits of a greater strength than about 58 o. p. (sp. gr. 8335), or containing more than about 85% by WEIGHT, or 90% by VOLUME, of pure alcohol, are commonly so called.

Alcohols. In perfumery, rectified spirit of wine, or commercial alcohol, holding essential oils or other odorous matters in solution.

ALCOOLATIFS (alcoölatifs). [F.] Syn. ALCOHOLATI′VA, L. In Fr. pharmacy, alcoholic solutions of liniments, embrocations, &c., whether made by distillation, maceration, or solution.

ALCOOLATS (alcoölats). [Fr.] In Fr. pharmacy, spirits; applied by Béral, Henry and Guibourt, and others, to medicated distilled spirits.

ALCOOLATURES (alcoölatures). [Fr.] Syn. Alcoholatu′′ra, L. In. Fr. pharmacy, alcoholic tinctures, elixirs, &c. M. Béral confines the term to vegetable juices preserved by alcohol.

ALCOOLES (alcooölés). [Fr.] Tinctures; the ‘teintures alcoholiques’ of the Fr. Codex.

ALCOOLIQUES (alcoöliques). [Fr.] Syn. Alcohol′ica, L. In Fr. pharmacy, alcoholic or spirituous solutions. (Béral.)

AL′CORNINE (-nĭn). [Eng., Fr.] Syn. Alcor′nocine (-sĭn); Alcor′neum, Alcorni′na, L. A crystallisable substance, apparently intermediate between fat and wax, discovered by Biltz, in alcornoco bark.

ALCORNO′CO. Syn. A.-bark; Alcornoque, Fr.; Alkornoc, A.-rind, Ger. The bark of an unknown tree of South America. It is astringent and bitter, and has been highly extolled as a specific in phthisis; but appears to possess little medicinal virtue. The bark of the young branches of the cork tree (quercus suber), used in tanning, is also sometimes called alcornoco-bark; but possesses none of the characters of the former article.

AL′DECAY. The galls on the leaves of myrobalanus chebula (Gaertn.), a forest-tree of Bengal. Equal to the best oak-galls.

AL′DEHYD (-hīd). [al-(cohol)-dehyd (rogenatus).] C₂H₄O. Syn. Hydrated oxide of acetyle; Hydrate of othyle*; Hydroxide of O.* Literally, dehydrogenated alcohol. In chemistry, a peculiar ethereal liquid, first obtained in a pure form by Liebig, from alcohol. It is produced under various circumstances, particularly during the destructive distillation of certain organic matters, and in several processes of oxidation. The following are the most convenient methods of preparing it:—

Prep. 1. (Liebig.) Sulphuric acid, 3 parts; is diluted with water, 2 parts; and as soon as the mixture has cooled, alcohol of 80%, 2 parts, is added; and, subsequently, peroxide of manganese (in fine powder), 3 parts. The whole, after agitation, is then distilled at a very gentle heat, from a spacious retort into a receiver surrounded with ice, the connection between the two being perfectly air-tight. The process is continued until frothing commences, or the distillate becomes acid which generally occurs when about one third (3 parts) has passed over. The distillate is next agitated in a retort, with about its own weight of fused chloride of calcium, in powder; after which about one half only is drawn over at a very77 gentle heat (85° to 90° Fahr.), by means of a water bath. This rectification is repeated in a precisely similar way. The last distillate is ANHYDROUS ALDEHYD only slightly contaminated with foreign matters.

2. (Liebig.) Aldehyd-ammonia, 2 parts, is dissolved in an equal weight of distilled water; and, after being placed in a retort, sulphuric acid, 2 or 3 parts, previously diluted with rather more than its own weight of distilled water, and allowed to cool, is added. The whole is now distilled, by means of a water bath, into a receiver surrounded with ice, or (preferably) a freezing-mixture, the temperature of the bath at first being very low, and the operation being stopped as soon, or rather before the water begins to boil. The distillate is then placed in a retort connected with a well-cooled receiver, as before; and after all the joints are made perfectly tight, powdered fused chloride of calcium, in weight equal to that of the liquid in the retort, is added through the tubulature. The heat produced by the hydration of the chloride causes the distillation to commence, after which it is carried on, by means of a water bath, at a temperature ranging from 80° to 82° Fahr. This rectification being very carefully repeated, the last distillate is PURE ANHYDROUS ALDEHYD.

Prop., &c. Limpid, colourless, ethereal, neutral, inflammable; mixes in all proportions with alcohol, ether, and water; odour peculiar, penetrating, and, when strong, exceedingly suffocating, the vapour, in quantity, producing spasmodic contraction of the thorax; boils at 72° Fahr. (70°—Ure, 5th ed.); sp. gr. ·790 at 60°, and ·800 at 32° Fahr.; sp. gr. of vapour, 1·532; by exposure to air it is gradually converted into acetic acid, and speedily so under the influence of platinum-black; heated with caustic potash, a brown substance resembling resin (ALDEHYD-RESIN) is formed; gently heated with protoxide of silver, or its solutions, metallic silver is deposited on the inner surface of the vessel, in a uniform and brilliant film, whilst ALDEHYDATE OF SILVER remains in solution; heated with hydrocyanic acid it yields ALANINE. By age, even in close vessels, it passes into one or more isomeric compounds (ELALDEHYDE; METALDEHYDE), with change of properties. Aldehyde for experiments should, therefore, be always recently prepared; and it must be kept in a well-stopped bottle, in a very cold place, and preferably in ice.

Obs. Aldehyd is important for its assumed position in the acetyl-series, and the part which it plays in the process of acetification, &c. The word is now also commonly employed, by chemists, as a generic term for any organic substance which, by assimilating two atoms of hydrogen, yields, or would yield, a compound having the composition or properties of an alcohol; or which, by taking up one atom of oxygen, yields an acid. Many of the essential oils (as those of almonds, cinnamon, and cumin) are composed principally of bodies which may thus be called aldehyds. One of the most valuable properties of these substances, is their strong tendency to combine with the bisulphites of ammonium, potassium, and sodium; and by which they may be separated from complex mixtures.

AL′DEHYD-AMMO′NIA (-hĭd-). An ammonia-compound of aldehyd, discovered by Döbereiner and Liebig.

Prep. (Liebig.) Aldehyd (of process No. 1, above) is mixed with an equal volume of ether,[16] in a flask surrounded with ice, or (what is better) a freezing-mixture; and is then saturated with dry gaseous ammonia. The crystals which soon form, after being washed with ether, and dried by means of bibulous paper and a short exposure to the air, are pure aldehyd ammonia.

Prop., &c. It smells like a mixture of turpentine and ammonia; melts at 165° to 170°; volatilises, unchanged, at 212° Fahr.; decomposed by exposure to the air; very soluble in water; soluble in alcohol, and more or less so in most other menstrua, except ether; acids decompose it. With sulphuretted hydrogen it forms thialdine.—Use. Chiefly to make pure aldehyd (which see).

AL′DER (awl′-). Syn. Al′der-tree; Al′nus (ăl-), L.; A. glutino′sa (Gaertn.); Betu′la alnus, Linn.; Aune, Aulne, Fr.; Erle, Ger. A well-known English tree, chiefly growing in moist grounds near rivers. Its wood is used for hurdles, for various articles of turnery and furniture, and when converted into charcoal, for making gunpowder; it possesses considerable durability under water; but is otherwise of little value. Bark and leaves very astringent, and reputed vulnerary; decoction used as a gargle in sore throat, and, in double the dose of cinchona, as a febrifuge in agues; bark and sap used in dyeing and tanning. The following belong to different nat. orders and genera to the preceding:—

Alder, Black. Syn. Win′ter-berry; Pri′nos verticilla′tus, Linn. A tree growing in the United States of America. Bark febrifuge, tonic, and astringent; berries tonic and emetic. (Bigelow.) It has been much recommended in dropsies, diarrhœa, intermittents, &c. Dose (of the dried bark), ¹⁄₂ to 1 dr., 3 or 4 times a day.

Alder-tree, Black. Syn. Berry-bearing alder-tree; Rham′nus fran′gula, Linn. A large shrub found in the woods and thickets of England, &c. Wood, BLACK DOG′WOOD; bark, bitter, emetic, purgative; used to dye yellow; root-bark, a drastic purgative; berries, purgative, emetic; unripe berries yield SAP-GREEN; charcoal of the wood esteemed the best for gunpowder.

ALE. Syn. Barley Wine*; Aile, Fr.; Weiss-bier, Ger.; Ael, Eale, Sax.; Cerevis′ia alba, C. lupula′ta, A′la*, Al′la*, L.78 Pale-coloured beer, prepared from lightly dried malt, by the ordinary process of brewing. The ale of the modern brewer is manufactured in several varieties, which are determined by the wants of the consumer, and the particular market for which it is intended. Thus, the finer kinds of Burton, East India, Bavarian, and other like ales, having undergone a thorough fermentation, contain only a small quantity of undecomposed sugar and gum, varying from 1 to 5 per cent. Some of these are highly ‘hopped,’ or ‘bittered,’ the further to promote their preservation during transit and change of temperature. Mild or sweet ales, on the contrary, are less attenuated by lengthened fermentation, and abound in saccharine and gummy matter. They are, therefore, more nutritious, though less intoxicating, than those previously referred to.

In brewing the finer kinds of ale, pale malt and the best East Kent hops of the current season’s growth, are always employed; and when it is desired to produce a liquor possessing little colour, very great attention is paid to their selection. With the same object, the boiling is conducted with more than the usual precautions, and the fermentation is carried on at a somewhat lower temperature than that commonly allowed for other varieties of beer. For ordinary ale, intended for immediate use, the malt may be all pale; but, if the liquor be brewed for keeping, and in warm weather, when a slight colour is not objectionable, one fifth, or even one fourth of ‘amber malt’ may be advantageously employed. From 4¹⁄₂ lbs. to 6 lbs. of hops is the quantity commonly used to the quarter of malt, for ‘ordinary ales,’ and 7 lbs. to 10 lbs. for ‘keeping ales.’ The proportions, however, must greatly depend on the intended quality and description of the brewing, and the period that will be allowed for its maturation.

The stronger varieties of ale usually contain from 6 to 8% of ‘absolute alcohol,’ ordinary strong ale, 4¹⁄₂ to 6%; mild ale, 3 to 4%; and table ale, 1% to 1¹⁄₂%; (each by volume); together with some undecomposed saccharine, gummy, and extractive matter, the bitter and narcotic principles of the hop, some acetic acid formed by the oxidation of the alcohol, and very small and variable quantities of mineral and saline matter. For the adulterants of ale, see Porter. See Beer, Brewing, Fermentation, Malt-liquors, &c.

Ale, Dev′onshire White. A liquor once generally drunk, and still in demand, in the neighbourhood of Kingsbridge and Modbury, Devon.

Prep. Ordinary ale-wort (preferably pale) sufficient to produce 1 barrel, is slowly boiled with about 3 handfuls of hops, and 12 to 14 lbs. of crushed groats, until the whole of the soluble matter of the latter is extracted. The resulting liquor, after being run through a coarse strainer, and become lukewarm, is fermented with 2 or 3 pints of yeast; and, as soon as the fermentation is at its height, is either closely bunged up for ‘draught,’ or is at once put into strong stoneware bottles, which are then well corked and wired.

Obs. White ale is said to be very feeding, though apt to prove laxative to those unaccustomed to its use. It is drunk in a state of effervescence or lively fermentation; the glass or cup containing it being kept in constant motion, when removed from the mouth, until the whole is consumed, in order that the thicker portion may not subside to the bottom.

Ales, Med′icated. Syn. Bryt′oles; Brutolés, Fr.; Cerevis′iæ Medica′tæ, L. In pharmacy, ale prepared by macerating medicinal substances in it, either at the ordinary temperature of the atmosphere, or when heated; infusions and decoctions, in which ale or beer is employed as the menstruum. The old dispensatories enumerate several medicated ales; such as CEREVISIA OXYDOR′CICA, for the eyes; C. ANTI-ARTHRIT′ICA, for the gout; C. CEPHAL′ICA, for the head; C. EPILEP′TICA, against epilepsy; &c. Preparations of this kind are now seldom ordered by the faculty, and their use is chiefly confined to the practice of empirics, and to domestic medicine. Bark, rue, savine, antiscorbutic plants, aromatic bitters, and stomachics, are the substances most commonly administered in this way. Ale in which wormwood, gentian, orange-peel, and the like, have been steeped, taken warm early in the morning, is much esteemed as a restorative tonic by drunkards and dyspeptics. See Beer, Purl, &c.

ALE′BERRY. A beverage made by boiling ale with spice, sugar, and bread-sops; the last commonly toasted. A domestic remedy for a cold.

ALE′GILL (g hard). Ale or beer flavoured or medicated by infusing the leaves of ground ivy in it; pectoral, stomachic, and nervine.

ALE′WIFE. The clupea serrata, an American species of herring. Its proper name is a′loof, although the established pronunciation and common orthography is ale-wife.

ALEM′BIC. Syn. Moors′head†; Alem′bicus, L.; Alambic, Fr.; Destillirkolben, Ger. An old form of distillatory vessel usually made of glass or earthenware, but sometimes of metal. The body (a) which holds the liquid for distillation is called the CU′CURBIT; the upper part (b) the HEAD or CAP′ITOL; (c) is the RECEIVER. It is still employed in the79 laboratory, in the distillation of articles that are apt to spurt over into the neck of the common retort, and thus vitiate the product.

ALEUROM′ETER. Syn. Aleuromètre, Fr. An instrument for determining the quantity and quality of gluten in wheat-flour, invented by M. Boland. It essentially consists of a hollow copper cylinder, about 6 inches long, and ³⁄₄ of an inch internal diameter. This tube has two principal parts; the one, about 2 inches long, is closed at the lower end, forming a kind of cup, into which the gluten is placed; it screws into the remainder of the cylinder. The cup being charged with a sample of gluten, and the upper part of the cylinder being screwed on, it is exposed in an oven, or (preferably) in an oil bath, to a temperature of 350 to 380° Fahr.[17] From the length of the tube the gluten occupies in swelling, as measured by a graduated scale, its quality is determined. The ‘crude gluten’ of good wheat-flour augments to four or five times its original volume, when thus treated; but that from bad flour does not swell, becomes viscid and semi-fluid, and generally gives off a disagreeable odour; whilst that of good flour merely suggests the smell of hot and highly baked bread.

AL′GA. (-gă). [L.] Sea-weed. A common name of grass-wrack (‘zostera marina’—Linn.), though not one of the algæ.

AL′GÆ. (ăl′-jē). [L. pl.] Syn. Al′gals; Algæ (DC.), Al′gales (Lindl.), L.; Algues, Varech, Fr.; Alge, Meergrass, Seegrass, Ger. Sea-weeds. In botany, an order of Thallogens living in water or very moist places, nourished throughout their whole surface by the medium in which they live, having no distinct axis of vegetation, and propagated by zoöspores, coloured spores, or tetraspores. Linnæus defines them—“plants, the roots, leaves, and stems of which are all in one.” The algæ consist either of simple vesicles lying in mucus, or of articulated filaments, or of lobed fronds formed of uniform cellular tissue. Those that vegetate in salt water are popularly called SEA-WEEDS (fu′ci, L.) and LA′VER (ulvæ, L.); those found in fresh water CONFER′VÆ. One of their divisions (the Zoöspermeæ) comprehends the lowest known forms of vegetable life, being merely adhering cells, emitting, at maturity, seeds or sporules having a distinct animal motion. In Oscillatorias, the whole plant twists and writhes spontaneously; and Zymenas actually copulate like animals. Some of the Algæ possess great beauty. In the lower grades the colour is green; in the higher, red or purple.

Prop., Uses, &c. None of the Algæ are poisonous. Several are nutritious, emollient, and demulcent, from containing mucilage (carrageenin), starch, sugar (mannite), and a little albumen; and are hence used as esculents. The ash from the dried weed varies in different varieties from 9% to fully 25%; and contains variable quantities of potassa, soda, lime, magnesia, iron, manganese, and silica, with sulphuric acid, phosphoric acid, chlorine, and a little iodine and bromine. (Schweitzer; Forchhammer; Gödechens.) Sea-weeds, their charcoal, and their ashes, have been long regarded as alterative and resolvent; and anti-phthisic virtues have been attributed to them by Laennec and others. They were formerly much given in scrofulous affections and glandular enlargements; but their use is now almost superseded by that of iodine and its preparations. Dr Stenhouse has proposed some of the algæ as furnishing an economical source of mannite. The sea algæ are used for manure; their ashes form KELP.

The following table, showing the results of several analyses of different kinds of algæ, and illustrating the very large amount of nitrogen contained in them, is from Mr Walter Blyth’s excellent dictionary of ‘Hygiene and Public Health.’

Kinds of Algæ.	Water.	Dry matter.	Per cent. Nitrogen in dry matter.	Protein contained in dry matter.
Chondrus crispus, bleached, from Bewlay Evans.	17·92	82·08	1·534	9·587
Chondrus crispus, unbleached, Ballycastle.	21·47	78·53	2·142	13·387
Gigastina mamillosa, Ballycastle.	21·55	78·45	2·198	13·737
Chondrus crispus, bleached, second experiment.	19·79	80·21	1·485	9·281
Chondrus crispus, unbleached second experiment.	19·96	80·04	2·510	15·687
Laminaria digitata, or dulse tangle.	21·38	78·62	1·588	9·925
Rhodomenia palmata.	16·56	83·44	3·465	21·656
Porphyra laciniata.	17·41	82·59	4·650	29·062
Iridæa edulis.	19·61	80·39	3·088	19·300
Alaria esculenta.	17·91	80·09	2·424	15·150

From the above, we learn the important fact that the sea-weeds found on our coasts are amongst the most nutritious of vegetable substances, and that they, when dry, are even richer in nitrogenous matter than either oatmeal or Indian corn in the same state. The following are the chief varieties of algæ which are used as food by the dwellers on our coasts as well as on the continent:—Porphyra laciniata and VULGARIS, called laver in England, stoke in Ireland, and slouk in Scotland. Chondrus crispus, called carrageen or Irish moss, and also pearl-moss, and sea-moss. Laminaria digitata, known as the sea-girdle in England, tangle in Scotland, and red-ware in the Orkneys; and Laminaria saccharina, Alaria esculenta, or bladder-lock, called also henware, and honey-ware by the Scotch. Ulva latissima or Green Laver—Rhodomenia palmata or dulse of Scotland. Under the name of “marine sauce” the Laver was esteemed a luxury in London, where it may now occasionally be met with in the shops of provision merchants. The employment of the Chondrus crispus or Carrageen in the form of an aliment for consumptive and weakly persons, would seem from the analysis of it given above to be fully justified. In preparing the algæ for food, they must be soaked in water to remove the saline matter, and where they are possessed of a bitter flavour this may be removed by adding a little carbonate of soda to the water. They should then be stewed in water or milk till they are tender. The best flavourings are pepper and vinegar. See Jelly.

ALGARO′BA. Syn. Ca′′rob-tree, St. John’s Bread; Cerato′nia Sil′iqua, Linn. A leguminous tree of southern Europe, Palestine, and part of Africa. Pods (ALGAROBA BEANS), used for food, and to improve the voice; they contain a sweetish, nutritious powder, and are supposed to have been the ‘locusts’ on which St. John fed in the wilderness; their decoction has been used as a pectoral in asthma and coughs.

Algaroba or Algarovil′la. The astringent pods of prosopis pallida, p. siliquastrum, and Inga Marthæ (South American trees), bruised and more or less agglutinated by the extractive exudation of the seed and husks. They are used in tanning, for which purpose they have been strongly recommended; indeed that of Chili, and of Santa Martha (New Carthagena), is said to possess “four times the power of good oak bark” (Ure); and in dyeing are only inferior to oak-galls.

ALGONTINE. A mouth and tooth wash. An aqueous solution of nitrate of potassium, aromatised with oil of peppermint, tincture of myrrh, and tincture of cinnamon.

ALGOPHON (Bernhard, Salzburg). For pains in decayed teeth. A solution of ethereal oil of mustard (2 grms.) in spirit of cochlearia (30 grms.), coloured green by saffron and litmus. (Wittstein.)

AL′IMENT. [Eng., Fr.] Syn. Alimen′tum, L.; Nahrung, Speise, Ger. Food; nutriment; anything which nourishes or supports life.

ALIMENT′ARY Syn. Alimenta′′rius, L.; Alimentaire, Fr.; zur Nahrung gehörig, Ger. Pertaining to food or aliment; nutrimental; nourishing.

Alimentary Canal′. Syn. Alimentary duct; Cana′lis Alimenta′′rius, L. In anatomy, the cavity in the bodies of animals into which the food is taken for the purpose of being digested; the whole passage or conduit extending from the mouth to the anus. In some of the lower animals this is a simple cavity, with only one opening; when the same aperture which admits the food also gives egress to the excrementitious matter. In others it is a true canal, with both a mouth and an outlet. Another step, and we find this canal is divided into a stomach and intestines. In the higher grades, a mouth, pharynx, and œsophagus precede the stomach. Birds have one or two sacculi or crops added to the œsophagus. The stomach of the ruminants consists of four sacs or parts, each of which may be regarded as a separate stomach; that of the bottle-nose whale contains no less than seven of such sacs. The part below the stomach, forming the intestines, is also variously subdivided, complicated, and connected. In man, these subdivisions are termed—DUODENUM, JEJU′NUM, IL′EUM, CÆ′CUM, CO′LON, and REC′TUM; the lower end or orifice of the last being called the A′NUS. The existence of an alimentary canal is said to be the only true characteristic of an animal. Plants have no common receptacle for their food, nor canal for carrying away effete matter; but every animal, however low in the scale of being, possesses an internal cavity which serves it as a stomach.

Alimentary Sub′stances. Syn. Aliments; Mate′′ria alimenta′′ria, L. Substances employed as food.

ALIMENTA′TION. [Eng., Fr.] Syn. Alimenta′tio, L.; Nahrhaftigkeit, Ger. The act, process, power, or state of nourishing, or being nourished.

ALIZARIN. C₁₀H₆O₃ . 2H₂O. Syn. Lazaric Acid. A red colouring matter obtained from madder.

Prep. 1. Exhaust madder with boiling water, and precipitate the decoction by sulphuric acid. Wash the precipitate, and, while yet moist, boil it with a concentrated solution of hydrate of aluminum in hydrochloric acid, and mix the solution with hydrochloric acid; red flakes of impure alizarin deposit. Dissolve this precipitate in alcohol or in dilute ammonia, and treat the solution with hydrate of aluminum. Boil the aluminum compound thus formed with carbonate of sodium, and, after freeing it from resinous impurities by digestion with ether, decompose it with hot hydrochloric acid. Wash the alizarin thus separated, dry it81 by simple exposure to air, and purify it by repeated crystallisation out of alcohol.

2. Sublime on a paper an alcoholic extract of madder. This method yields the purest alizarin.

Props. Red prisms; sublimes at 419° F.; odourless, tasteless, and neutral to test-paper; sparingly soluble in water, even at the boiling temperature; soluble in alcohol and ether; not decomposed by hydrochloric acid; dissolved, without decomposition, by strong sulphuric acid; soluble in solutions of the alkalies and their carbonates; acids precipitate alizarin from its alkaline solutions in orange-coloured flakes; alumina decolorises an alcoholic solution of alizarin, forming a red lake.

ALIZARIN, ARTIFICIAL. C₁₄H₈O₄. This colour was first obtained by Graebe and Liebermann in 1869 from anthrachinon, an oxidation product of anthracen, this latter being a substance which is formed during the destructive distillation of coal-tar. These chemists converted anthracen into antichinon by means of nitric acid.

The crude anthracen is previously purified by treatment with benzoline (petroleum spirit), aided by heat, and by being subjected to the action of the centrifugal machine to fusion, and to sublimation.

According to the original method of preparing alizarin, the anthrachinon was first converted into a dibromide of anthrachinon by treatment with bromine, and this bromated compound, by further treatment either with caustic potash or soda at a temperature of 180° to 200° C., converted into alizarin-potassium (or alizarin-sodium if caustic soda has been used), from which the alizarin is set free by means of hydrochloric acid.

Alizarin is now procured from anthrachinon by treatment at a temperature of 260° C., with concentrated sulphuric acid of 1·84 sp. gr., the anthrachinon being converted into a sulpho-acid; this acid is next neutralised with carbonate of lime, the fluid decanted from the deposited sulphate of lime, and carbonate of potash added to it, with the object of throwing down all the lime. The clear liquid is then evaporated to dryness, the resulting saline mass is converted into alizarin-potassium by heating it with caustic potash. From the alizarin-potassium thus obtained the alizarin is set free by the aid of hydrochloric acid.

In another method the preparation of anthrachinon is avoided, and anthracen employed directly, by first converting it, by means of sulphuric acid and heat, into anthracen sulphonic-acid. After having been diluted with water, the solution of this acid is treated with oxidising agents (peroxides of manganese, lead, chromic acid, nitric acid), and the acid fluid is afterwards neutralised with carbonate of lime. When peroxide of manganese has been used, the manganese is also precipitated as oxide. The oxidised sulpho-acid having been previously converted into a potassium salt, the latter being heated with caustic potash, alizarin is obtained. The details of these two processes will be found set forth in the terms of the patent taken out by Messrs Caro, Graebe and Liebermann, further on.

The following method of preparing alizarin from anthracene paranaphthalene and their homologues is by Girard. The material used is that which distils between 290° and 360°; it is purified by distillation and pressure, the portion which passes over, between 300° and 305°, being collected separately. This mixture is treated with potassium chlorate and hydrochloric acid, whereby it is converted into tetra-chlorinated products. These are oxidised either by nitric acid in the water bath, or by a metallic oxide (red or brown oxide of lead), and sulphuric or acetic acid. In the first place a mixture of dichloranthraquinine and chloride of chloroxyanthranyl are obtained. These substances are treated in presence of a metallic oxide (oxide of zinc, oxide of copper, or litharge), with an alcoholic solution of sodium acetate. The metallic oxide removes the last atom of chlorine from the sodium chloroxyanthranilate, and converts it, like the dichloranthraquinine, into alizarin. The purification is effected by means of benzine, petroleum, &c., which dissolve out the foreign matters, and by successive precipitation from the alkaline solutions by mineral acids. The foreign matters may also be separated by means of a little alum, when it is necessary to work with neutral potash or soda salts.

Another method for the preparation of alizarin has been patented by Dale and Schorlemmer. It is as follows: 1 part of anthracen is boiled with 4 to 10 parts of strong sulphuric acid, then diluted with water, and the solution neutralised with carbonate of calcium, barium, potassium, or sodium. The resulting sulphates having been removed by nitration or crystallisation, the solution is heated to between 180° and 260° with caustic potash or soda, to which a quantity of potassium nitrate or chlorate has been added, about equal in weight to the anthracen, as long as a blue-violet colour is thereby produced. From this product the alizarin is separated in the usual way by precipitation with an acid. Several other patents have been taken out for the preparation of artificial alizarin.

The specification of Messrs Caro, Graebe, and Liebermann, and dated June 25th, 1869, was the first which was taken out in England. We quote it here because it enters more fully into detail than any of the others.

“Our invention is carried into effect by means of either of the two processes which we will proceed to describe.

“In the one process we proceed as follows—We take about one part by weight of anthraquinone and about three parts by weight of sulphuric acid of about specific gravity of82 1·488, and introduce the same into a retort, which may be made of glass, or porcelain, or of any other material not easily acted upon by sulphuric acid, and the contents are then to be heated up to about 260° Centigrade, and the temperature is maintained until the mixture is found no longer to contain any appreciable quantity of unaltered anthraquinone. The completion of this operation may be ascertained or tested by withdrawing a small portion of the product from time to time, and continuing the operation at the high temperature until such product upon being diluted with water is found to form a substantially perfect solution, thereby indicating that the anthraquinone has become either entirely or in greater part converted into the desired product. The products thus obtained are then allowed to cool, and are diluted with water; carbonate of lime is then added in order to neutralise and remove the excess of sulphuric acid contained in the solution; the mixture is then filtered, and to the filtrate carbonate of potash, or carbonate of soda, by preference in solution, is to be added until carbonate of lime is no longer precipitated; the mixture is then filtered, and the clear solution is evaporated to dryness, by which means the potash or soda salts of the sulpho-acids of anthraquinone are obtained, and which are to be treated in the following manner:—We take about one part by weight of this product, and from two to three parts by weight of solid caustic, soda, or potash; water may be added or not, but by preference we add as much water as is necessary to dissolve the alkali after admixture; we heat the whole in a suitable vessel, and the heating operation is continued at a temperature of from about 180° to 260° Centigrade, for about one hour, or until a portion of the mixture is found upon withdrawing and testing it to give a solution in water, which being acidulated with an acid, for example, sulphuric acid, will give a copious precipitate of the colouring matters. The heating operation having been found to have been continued for a sufficient time, the resulting products are then dissolved in water, and we either filter or decant the solution of the same, from which we precipitate the colouring matters or artificial alizarin, by means of a mineral or organic acid, such, for example, as sulphuric or acetic acid. The precipitated colouring matters thus obtained are collected in a filter or otherwise, and after having been washed may be employed for the purpose of dyeing and printing, either in the same way as preparations of madder are now used or otherwise.

“In carrying out our other process we proceed as follows:—We take about one part by weight of anthracene and about four parts by weight of sulphuric acid of specific gravity of about 1·848, and the mixture being contained in a suitable vessel, is heated to a temperature of about 100° Centigrade, and which temperature is to be maintained for the space of about three hours; the temperature is then to be raised to about 150° Centigrade, which temperature is to be maintained for about one hour, or until a small portion of the product when submitted to the two subsequent processes hereinafter described is found to produce the desired colouring matters; we then allow the result obtained by this operation to cool, and dilute it with water, by preference in the proportion of about three times its weight. To the solution thus obtained we add for every part of anthracene by weight which had been employed in the previous operations, from about two to three parts by weight of peroxide of manganese, preferring to employ an excess, and we boil the whole strongly for some time, and in order fully to ensure the desired degree of oxidation the mixture may be subsequently concentrated, and by preference be evaporated to dryness, and the heat be continued until a small portion of the oxidised product, when submitted to the subsequent processes hereinafter described will produce the desired colouring matters. We then neutralise and remove the sulphuric acid contained in this mixture, and at the same time precipitate any oxides of manganese that may be held in solution, by adding an excess of caustic lime, which we use by preference in the form of milk of lime, and we add the same until the mixture has an alkaline reaction. We then filter, and add to the filtrate carbonate of potash or soda, until there is no further precipitation of carbonate of lime. The solution is then filtered and evaporated to dryness, and we thus obtain the potash or soda salts of what we call the sulpho-acids of anthraquinone.

“In effecting the conversion of the oxidised products thus obtained into colouring matters, or into what we call artificial alizarin, we proceed as follows:—We take one part by weight of this product, and from two to three parts by weight of solid caustic soda or potash, and water may be added or not, but by preference we add as much water as may be necessary to dissolve the alkali. After admixture we heat the whole in a suitable vessel, and continue the heating operation at a temperature of about 180° to about 260° Centigrade for about one hour, or until a portion of the mixture is found to give a solution in water, which upon acidulation with an acid, for example, sulphuric acid, is found to give a copious precipitate of the colouring matters. The heating operation having been found to have been continued for a sufficient time, we then dissolve the product in water, and either filter or decant the solution of the same, from which we precipitate the colouring matters or artificial alizarin by means of a mineral or organic acid, such, for example, as sulphuric or acetic acid. The precipitated colouring83 matters thus obtained are collected on a filter or otherwise, and after having been washed may be employed for the purpose of dyeing and printing, either in the same way as preparations of madder are now used or otherwise.

“Instead of acting upon anthracen by means of sulphuric acid of the density before mentioned, fuming sulphuric acid may be employed, but we prefer to use the ordinary kind before described.

“In order to effect the process of oxidation, before referred to, other oxidising agents may be used in the place of the oxide of manganese, before mentioned, such, for example, as perioxide of lead, or chromic, nitric, or other acids capable of effecting the desired oxidation may be employed.”

Mr W. H. Perkin’s patent is similar in principle to that of Messrs Caro, Graebe, and Liebermann, and is dated only one day later.

The following is an outline of a patent taken out in France in May, 1869, by MM. Brœnner and Gutzkon, for the manufacture of artificial alizarin. One part of anthracen is heated with two parts of nitric acid, sp. gr. 1·3 to 1·5. The anthraquinone thus produced is washed and dissolved at a moderate heat in sulphuric acid. Mercuric nitrate is now added, which converts the anthraquinone into alizarin, The mass thus formed is dissolved in an excess of alkali, which precipitates the oxide of mercury, and retains the colouring matters in solution. The alkaline liquor is decanted and neutralised with sulphuric acid, and the precipitate thus formed is washed and collected. If not quite pure the treatment with alkali must be repeated. (The complete specification of this patent is published in the ‘Moniteur Scientifique,’ vol. xi, p. 865.)

In England a large quantity of artificial alizarin is manufactured by the process of Mr Perkin, and is used as a substitute for madder and madder extract, in Turkey red dyeing and topical styles. The largest makers of artificial alizarin on the continent are Messrs Gessert Frères, of Ebelfort, Messrs Maister, Lucius and Co., of Hæchst, near Frankfort, and the Badische Anilin und Soda Fabric, Mannheim.

The following recipes for printing with artificial alizarin are extracted from Mr Crookes’ ‘Practical Handbook of Dyeing and Calico Printing’:

For double printing, when deep red is printed on first, the goods must be steamed one hour before the second printing takes place. After the second printing the goods are again steamed for one hour, and aged for twenty-four hours; they are then passed through one of the following baths, at from 120 to 140 F., remaining in the bath not longer than 1 to 1¹⁄₂ minute:—

The printed goods are steamed for an hour or two, and then aged from twenty-four to thirty-six hours. They are then padded in the chalk and arseniate of soda bath; after which they are washed and soaped in a single soap-bath without tin crystals; and, if needful, cleaned in a weak solution of bleaching powder.

Stir 30 lbs. of hydrate of alumina into six quarts of acetic acid, warm, filter, and reduce to the specific gravity required.

The hydrate of alumina is prepared by dissolving 72 lbs. of alum in 100 gals. of water, and 62 lbs. soda in 100 gals. of water. The two solutions are mixed, this precipitate is washed eight times by decantation, collected on a filter and pressed. It must be dissolved on the filter before it gets dry.

Dissolve and filter off the liquid from the precipitate, and dilute to proper standard.

The reds are turned more yellow by nitrate than by acetate of alumina, and when the former is used more acetate of lime is taken in addition.

A solution of acetate of lime at 25° Tw. contains 25 per cent. of acetate of lime; generally ¹⁄₁₀th of the weight of alizarin paste is required; but with a fresh quantity of alizarin it is safer to ascertain, on a small scale, the amount needed.

To obtain a yellower shade, for every quart of mixed colour, 1 oz. bark liquor, at 30° Tw., may be added.

Old spoiled red colours may be advantageously used for browns by adding per quart, ³⁄₄ oz. to 1 oz. red prussiate, dissolved in water.

ALKALI. Syn. Alkali, Fr.; Langensalz, Ger. This word has been used in various senses, but is now usually applied to four substances only, viz. the hydrates of potassium, sodium, lithium, and ammonium (the latter being supposed to exist in the aqueous solution of ammonia). In a more general sense it is applied to the hydrates of barium, strontium, and calcium, which, for the sake of distinction, are called the alkaline earths. The following properties are characteristic of the alkalies:—(1) They are soluble in water, the alkalies proper more so than the alkaline earths. (2) They change the hue of many vegetable colouring matters; thus, they turn reddened litmus blue, yellow turmeric brown, and syrup of violets and infusion of red cabbage green. (3) They neutralise the strongest acids. (4) They precipitate most of the heavy metals from solutions of their salts as hydrates or oxides. (5) They saponify the fixed oils and fats. (6) They exert a caustic or corrosive action on animal and vegetable substances.

ALKALI ACTS. The principal alkali Act is the 26 and 27 Vict., c. 24, amended by 37 and 38 Vict., c. 43, the amended Act having come into operation in 1875.

Every alkali work must be carried on so as to ensure the condensation of not less than 95% of muriatic acid evolved therein; and it must be so condensed that in each cubic foot of air, smoke, or chimney gases, escaping from the works into the atmosphere, there is not contained more than one fifth part of a grain of muriatic acid. Penalty for first conviction, £50; for second and other offences, £100, or less (26 and 27 Vict., c. 124, s. 4; 37 and 38 Vict., c. 43, s. 4).

The owner of every alkali work is also bound “to use the best practicable means of preventing the discharge into the atmosphere of all other noxious gases arising from such work; or of rendering such gases harmless when discharged.”

The noxious gases are defined to be sulphuric acid, sulphurous acid (except that arising from the combustion of coals), nitric acid, or other noxious oxides of nitrogen, sulphuretted hydrogen and chlorine (37 and 38 Vict., c. 43, ss. 5 and 8).

The owner is liable for any offence against the Alkali Acts, unless he prove that the offence was committed by some agent, servant, or workman, and without his knowledge, in which case the agent, &c., is liable (26 and 27 Vict., c. 124, s. 5).

Every alkali work must be registered; penalty for neglect £5 per day (ibid., s. 6).

Powers are given to owners to make special rules for the guidance of their workmen (ibid. s. 13).

ALKALIM′ETRY. Syn. Alkalime′tria, L.; Alcalimétrie, Fr. In chemistry, the estimation of the strength of the commercial alkalies; the art or process of determining the quantity or proportion of pure caustic alkali, or of its carbonate, in any given sample or simple solution. It is the reverse of ‘acidimetry,’ and it should be understood that it does not apply to alkalies occurring under any other form or condition than those just mentioned. Alkalimetric assays are now also frequently and conveniently extended to the estimation of the alkaline earths and their carbonates, as hereafter noticed.

Alkalimetrical processes. These, like those85 of ‘acidimetry,’ are for the most part founded on—the capacity of the bases to saturate acids—the estimation of the quantity of dry carbonic acid liberated from a given weight of an alkaline carbonate under the influence of a stronger acid; and, in the case of the pure alkalies, the sp. gr. of their solutions. From any one of these results the exact amount of alkali, or of alkaline carbonate, present in a sample, is easily found or calculated. These processes are, indeed, precisely similar to those described under Acidimetry; but here the unknown quantity sought is the alkali, instead of the acid.

Assay. The SAMPLE is drawn from as near the centre of the cask containing the alkali as possible, and at once placed in a wide-mouthed bottle, which is then closely corked up and numbered. Before proceeding to the assay, the contents of the bottle are thrown on a piece of dry paper, the lumps crushed small, and the whole reduced to coarse powder as rapidly as possible. The number of grains required for the trial are then at once weighed, placed in a phial or small glass tube, and agitated with about ¹⁄₂ oz. of hot water. After a short time allowed for repose, the clear liquid is poured off into a beaker-glass or other vessel in which the trial is to be made. This process is repeated with a second and a third quantity of water, or until nothing soluble remains, shown by the last washings not affecting the colour of turmeric paper. The greatest care must here be taken not to waste the smallest portion of the liquid, which would render the results inaccurate.

To the solution in the beaker-glass a little solution of litmus is added, unless the acid is tinted with it when it is unnecessary. The solution is now heated until near its boiling point, and a piece of white paper or porcelain put behind it, to better show up the changes of colour. The alkaline solution is now treated with the standard test-acid, which is poured carefully from an alkalimeter or Mohr’s burette, until the solution, after turning a purple red, suddenly assumes a pink colour. Neutralisation being thus effected, the operator allows the sides of the alkalimeter or burette to drain, and then either ‘reads off’ the number of divisions which have been consumed, or (if using the test-acid by weight) determines the quantity by again weighing the alkalimeter. The common practice is to allow two drops (= ¹⁄₅th of an alkalimetrical division by VOLUME, or 2 gr. by WEIGHT) for over-saturation, which is, therefore, deducted from the ‘observed quantity’ of the test-liquor employed.

In testing solutions of the PURE or CAUSTIC ALKALIES, the colour, on neutralisation, suddenly changes from blue to pink or red, without any intermediate vinous or purple colour being produced.

The quantity of test-acid used gives the absolute or per-centage composition of the sample examined, according to the constitution of the test-acid used.

Standard Acids. The various test-acids in use as described below, each being used by different operators as they think best.

The most convenient test-acid, or normal solution, both for commercial and chemical assays, is perhaps dilute sulphuric acid, which, when intended to be used VOLUMETRICALLY, has the sp. gr. 1·032 at 60° Fahr., and contains in 100 alkalimetrical divisions 1000 water-grains measure, or 1 litre, exactly 49 gr. (or grammes) of sulphuric acid; and when intended to be used GRAVIMETRICALLY, or by weight, has the sp. gr. 1·033, and contains in 1000 gr. (or grammes) weight exactly 49 gr. (grammes) of sulphuric acid; and, in both cases, consequently corresponds to 1 equiv. of every other base. These dilute acids are easily prepared by mixing 1 part of the concentrated acid with 11 or 12 parts of distilled water; the precise quantity depending on the strength of the acid employed, and must be so arranged that 1000 grains shall exactly neutralise 1000 grains of water containing 53 grains of pure anhydrous sodium carbonate.

This acid (as well as all those hereafter mentioned) may be kept faintly tinged with litmus, which is often more convenient than tinging the alkaline solution at the time of making the assay.

It will at once be seen that every alkalimeter division of the first of the above acids, and every 10 gr. of the second, represent the ¹⁄₁₀₀th part, or 1% of alkali whenever the equivalent weight [18] of the latter is taken for the assay. Every 1-10th part of an alkalimeter-division (or every drop), and every grain weight (when a Schüster’s alkalimeter is employed) then respectively represents the ¹⁄₁₀ of 1%; and the result sought is obtained without the necessity of any calculation.

This is obvious—for if the equivalent of a pure alkali or of its carbonate (i. e. one of 100%) requires an equiv. (100 alkalimeter-divisions, or 1000 gr.) of test-acid to saturate it, an alkali or alkaline carbonate of 75%, 50%, or 25%, will respectively require only 75, 50, or 25 divisions, or 750, 500, or 250 gr.; and so of other strengths in proportion. The only precaution necessary is always to take the standard weight for the assay answering to the equiv. of the denomination of the per-centage result sought. Thus, in testing a carbonate of potash, we may either wish to determine its per-centage richness in ‘dry carbonate,’ or in ‘pure potassa,’ the latter being usually the case. To obtain the first, we must take 69 gr. for the assay; and to obtain the second, 47 gr. With CAUSTIC ALKALIES, or mixtures containing them, the weight, in grains, taken for the assay, must always correspond to the equiv. of the pure base. See Table II, at the end of this article.

In commercial assays, when 100 gr. (or some86 aliquot part thereof) are taken for trial, the per-centage result is obtained from the number of alkalimeter-divisions, or the number of grains, of the test-acid consumed, by the common Rule of Proportion. Thus:—A crude sample of potash having taken 90 alkalimeter-divisions of test-acid to neutralise it, would contain—

or nearly 42¹⁄₃ per cent. of pure potassa. If only 50, 25, or 20 gr. are tested, the result must, of course, be double, quadruple, &c., as the case may be. Or the third term of the proportion may be multiplied by the denominator of the fraction representing the aliquot part. This, in the case of 50 gr. (repeating the above example), would be—

as before; but even these easy calculations may be simplified, as is shown below.

One of the advantages, and not the least, attending the use of test-acids corresponding to equivalents, is, that by means of the simple Rule of Three, the per-centage quantity of alkali may be found whether 100 or any other number of grains have been submitted to trial. For—The weight of the sample tested (in grains) bears the same relation to the equivalent weight of the alkali under examination, that the number of alkalimeter-divisions or of the grains of test-acid consumed do to the per-centage of alkali sought. Thus, with a sample of 33 gr. of pearlash taking 35 alkalimeter-divisions or 350 grains (every 10 gr. being = 1%) of test-acid for neutralisation, this would be—

or nearly 50 per cent. of pure potassa. By substituting the equiv. of the dry carbonate of potash (69), for that of pure potassa used above, the quantity of that article corresponding to the same weight of the pure alkali may be at once found. Repeating the last example this will be—

or nearly 73¹⁄₄ per cent. The same applies to all the alkaline bases and their carbonates.

For commercial purposes, there is used, amongst others, an empirical solution, as a test-acid for potassa, soda, and ammonia, to save the necessity of calculation.

This is dilute sulphuric acid having a sp. gr. of about 1·071; 100 alkalimeter-divisions (1000 water-grains measure) exactly saturate 100 gr. of pure potassa, or 113 gr. of anhydrous carbonate of soda. The number of measures consumed, read off by mere inspection from the scale of the alkalimeter, gives the exact per-centage of alkali in the sample examined, for POTASH; and by multiplying it by ·66, that for SODA also. By employing ·362 as the multiplier, it gives the like result for AMMONIA. In fact, occasionally, in order to save the necessity of any calculation, two ‘test-acids’ are frequently employed—the one for potash and the other for soda.

These are made by diluting sulphuric acid to a sp. gr. of near 1·071 and 1·086 respectively; 1000 grains, by measure, of the first neutralising exactly 100 grains of pure potassa, or 113 of pure anhydrous soda carbonate, and the latter neutralising exactly 100 grains of pure soda, or 171 gr. of pure anhydrous sodium carbonate.

There is another system of preparing standard acids by means of a Faraday’s alkalimeter. A strong acid is prepared by diluting sulphuric acid to a sp. gr. of 1·1268 at 60°, and 455·7 grains exactly neutralise 100 of anhydrous carbonate of soda.

The glass tube here referred to, and known as Faraday’s ALKALIMETER, is graduated centesimally, in the usual manner; but opposite the numbers 22·1, 48·62, 54·43, and 65, are cut the words ‘soda,’ ‘potassa,’ ‘carbonate of soda,’ and ‘carbonate of potassa,’ to indicate the quantity of the test-acid to be employed for each of these substances. (See engr.) It is used by pouring the test-liquor into it until it reaches the line marked against the alkali, or carbonate, under examination, the remaining divisions being filled up with pure water, and the whole well mixed by placing the thumb on the orifice of the tube and shaking it well. The measure of the resulting dilute acid must then be very carefully observed, and more water added, if required, to bring it up to the zero (0) or 1000 gr. on the scale; careful agitation being again employed as before. The test-acid thus prepared is then added, with the usual precautions, to the sample until exact neutralisation is effected. The quantity consumed for this purpose, read off from the graduated scale, expresses the exact per-centage of the pure ALKALI, or of its CARBONATE, as the case may be, contained in the sample examined, provided 100 gr. have been taken for the assay.

Another method sometimes used is that of M. Mohr, and practised as follows:—The alkaline solution, slightly coloured blue with litmus, is strongly super-saturated with a standard acid (sulphuric or oxalic) of known strength, supplied from an alkalimeter in the usual manner; the last traces of carbonic anhydride being removed by boiling, shaking, blowing into the flask, and, finally, sucking87 out the air. A standard solution of caustic soda (of a strength exactly corresponding to that of the test-acid already used) is now cautiously added, drop by drop, until the colour, rendered yellowish-red by the acid, just appears of a light blue. The difference between the quantity of the solution of the test-alkali and of the test-acid consumed, expresses the exact quantity of acid neutralised by the alkali, and hence also its strength.

Besides the above methods, the alkaline carbonates are analysed, by the loss of carbonic anhydride (carbonic acid) they suffer, by being decomposed by a strong acid. The best method in use is that of MM. Fresenius and Will, and depends on the same principle, and is performed in a similar manner and in a similar apparatus to that described under Acidimetry; the only difference being that here the uses of the small tube (e) is dispensed with, and that the alkali is tested under the form of carbonate, instead of bicarbonate.

Oper. The smaller flask (B) is about half filled with concentrated sulphuric acid, and the sample of alkali, in solution (under the form of carbonate), being placed in the larger flask (A), water is added until it is about one third full. The tubes are then fitted into the apparatus quite air-tight; the end of the tube (b) is fastened with a piece of wax, and the whole is very carefully weighed. The apparatus is now removed from the scales, and a perforated cork, or a small piece of india-rubber tube, being temporarily applied to the end of the tube (h), a few bubbles of air are sucked out of the flask (B) by means of the lips; the consequence of which is, that on removing the mouth the acid in (B) ascends to a certain height in the tube (c). If in a short time this little column of liquid maintains its height in the tube, it is a proof that the apparatus is perfectly air-tight, and as it should be. Suction is now again cautiously applied to the tube (h) and a little of the acid in (B) made to flow over into the flask (A), the quantity being proportionate to the vacuum produced by suction, and capable of being regulated at will. No sooner does the acid come into contact with the carbonate in the flask (A) than the evolution of carbonic acid commences, and this, from the construction of the apparatus, having to pass through the concentrated sulphuric acid, is rendered quite dry before it can escape by the tube (d) into the atmosphere. Whenever the effervescence flags, a little more acid is sucked over, until the whole of the carbonate is decomposed; after which an additional quantity is made to pass into (A), so as to raise the temperature considerably, for the purpose of expelling all the gas absorbed by the fluid during the operation. As soon as this is effected, the wax is removed from the aperture (b), and suction applied to (h), until all the carbonic acid in the apparatus is replaced by atmospheric air. The whole is now allowed to cool, and (together with the piece of wax removed) is again accurately weighed. The loss of weight gives the exact amount of dry carbonic anhydride, or anhydrous carbonic acid, which was contained in the specimen, from which the weight of PURE ALKALI is readily estimated, as every 22 gr. of dry carbonic acid gas evolved represents exactly 31 gr. of pure SODA, 47 gr. of pure POTASSA, &c. &c.; these numbers being the equivalents of the respective substances from which the per-centage strength may be found by the rule of proportion, as before explained.

Thus, in the case of a 100-gr. sample of carbonate of soda which has lost 15¹⁄₄ gr. of carbonic acid, by the assay, this would be—

or nearly 21¹⁄₂ per cent. of pure soda. If 53, the equiv. of anhydrous carbonate of soda, be taken, instead of 31 (the eq. of pure soda), the answer would have been, in the terms of that substance, 36·748%, or nearly 36³⁄₄ per cent. When an aliquot part of 100 gr. has been taken for the assay, either the result, or the third term of the proportion, must, of course, he multiplied by the denominator and divided by the numerator of the fraction representing such aliquot part.

By multiplying the weight of carbonic anhydride lost, by the numbers opposite the names of the respective alkalies and their carbonates in the second column of the following Table the equivalent per-centage value of the carbonates examined may be obtained in terms corresponding to the various denominations named therein, when 100 gr., or any aliquot part of 100 gr., have been tested; the result, in the latter case, being, of course, multiplied as before.

By taking certain standard weights for the assay, the quantity of carbonic acid evolved may be made to furnish the per-centage strength or value of the specimen in the terms of either the pure or carbonated alkalies, whether in their anhydrous or hydrated state. The numbers in the second column of the following Table represent the quantity in grains and decimal parts of each of the substances named in the first column, equivalent to one grain of carbonic anhydride. These numbers, as already mentioned, may be employed as factors for converting any numbers representing grains of that acid into the equivalents of these substances, true to 4 places of decimals; and further, they furnish us with the data for determining the exact number of grains which must be tested, so that the loss of weight in carbonic anhydride shall at once give us the per-centage richness of the sample in the terms of the denomination for which it is taken. The numbers in the third column of the Table, formed by simply moving the decimal point of the numbers in the second column one figure further to the right, indicate the weights to be taken for the assay, so that the loss of weight, reckoned in tenths of a grain, exactly represents the per-centage88 strength in the terms sought. The weights corresponding to the numbers in the fifth column give the same results, provided the loss of weight is reckoned in quarter-grains; those in the sixth column effect the same when the loss of weight is reckoned in half-grains; whilst those in the last column require that the gas eliminated should be counted in grains, and are simply the numbers in the second column of the Table multiplied by 100, or reproduced by moving the decimal point two figures to the right.

NAMES, &c.	Factors or Multipliers for converting the weight of carbonic acid expelled into real strengths.	Quantity (in grains) to be taken, so that the per-centage value of the sample tested shall be shown in the terms of any of the denominations given, by the weight of the evolved Carbonic Acid reckoned—
		In tenths of a grain.
		Whole numbers and decimals.	Nearest common numbers.	in quarter-grains.	in half-grains.	in grains.
Ammonia (pure, gaseous)	·77273	7·727	7³⁄₄	19¹⁄₃	38⁵⁄₈	77³⁄₀
Carbonate of ammonia (neutral, anhydrous)	1·77273	17·727	17³⁄₄	44⁵⁄₁₆	88⁵⁄₈	177¹⁄₄
Carbonate of ammonia (neutral, crystallised)	1·9773	19·773	19³⁄₄	49⁷⁄₁₆	98⁷⁄₈	197³⁄₄
Sesquicarbonate of ammonia (translucent)	2·6818	26·818	26¹³⁄₁₆	67¹⁄₁₀	134¹⁄₁₀	268¹⁄₅
Bicarbonate of ammonia (crystallised)	3·5909	35·909	35⁹⁄₁₀	89¹³⁄₁₆	179⁵⁄₈	359¹⁄₁₀
Potassa (anhydrous)	2·1364	21·364	21¹⁄₂	53¹⁄₂	107	213³⁄₈
Hydrate of potassa	2·54546	25·455	25⁵⁄₁₁	63⁵⁄₈	127¹⁄₄	254¹⁄₂
Carbonate of potassa (anhydrous)	3·1364	31·364	31³⁄₈	78¹⁄₂	157	313¹⁄₂
Carbonate of potassa (granulated)	3·7727	37·727	37¹⁄₂	94³⁄₁₀	188⁵⁄₈	377¹⁄₄
Carbonate of potassa (crystallised)	3·9545	39·545	39⁵⁄₈	99	198	395¹⁄₂
Bicarbonate of potassa (crystallised)	4·5454	45·454	45¹⁄₂	113³⁄₄	227¹⁄₂	454¹⁄₂
Soda (anhydrous)	1·4091	14·09	14¹⁄₁₀	35¹⁄₄	70¹⁄₂	141
Hydrate of soda	1·8182	18·182	18¹⁄₅	45¹⁄₂	91	182
Carbonate of soda (anhydrous)	2·4091	24·091	24¹⁄₁₀	60¹⁄₄	120¹⁄₂	241
Carbonate of soda (crystallised)	6·5	65·	65	162¹⁄₂	325	650
Sesquicarbonate of soda (dry; theoretical)	2·9091	29·091	29¹⁄₁₀	72¹⁄₂	145	290
Sesquicarbonate of soda (Ph. L., 1836)	3·7273	37·273	37¹⁄₄	93¹⁄₄	186¹⁄₂	373
Sesquicarbonate of soda (average commercial)	3·7954	37·954	38	94⁷⁄₈	189³⁄₄	379¹⁄₂
Bicarbonate of soda (crystallised)	3·8182	38·182	38¹⁄₅	95¹⁄₂	191	382
Lithia (pure, anhydrous)	·6818	6·818	6¹³⁄₁₆	17¹⁄₂₀	34¹⁄₁₀	68¹⁄₅
Baryta (pure, caustic)	3·4773	34·773	34⁴⁄₅	86⁷⁄₈	173⁷⁄₈	347³⁄₄
Lime (pure, caustic)	1·2727	12·727	12³⁄₄	31³⁄₄	63⁵⁄₈	127¹⁄₄
Magnesia (pure, anhydrous)	·90909	9·091	9¹⁄₁₁	22³⁄₄	45¹⁄₂	91

In this ingenious method of alkalimetry it is absolutely necessary that the whole of the alkali in the specimen tested should be in the state of neutral carbonate. If a sample of potash contains any caustic alkali (as the potashes and pearlash of commerce generally do), Fresenius and Will direct it, previously to being tested, to be triturated with its own weight of pure quartzose sand, and about one third of its weight of carbonate of ammonia; and the resulting mixture, placed in a small iron capsule, or a porcelain crucible, to be moistened with water, and exposed to a gentle heat until it becomes quite dry, and all the ammonia is expelled. If the sample contains any bicarbonate or sesquicarbonate, it must be heated to dull redness before being placed in the apparatus and tested. In the case of crude soda (particularly soda ash), the proportion of carbonate of ammonia should be equal to at least one half the quantity operated on. With both alkalies, if the sample contains sulphides, sulphites, or hyposulphites, the same method is to be followed, except that solution of ammonia,89 instead of water, is to be employed for moistening the powder. To remedy the error which would arise from the apparent amount of carbonic anhydride liberated during the assay, being swelled by the disengagement of ‘sulphuretted hydrogen’ or sulphurous acid from these substances, a small quantity of neutral (i. e. yellow) chromate of potash may be added to the alkaline solution in the flask (A); by which they will be converted into sulphates, sulphur, and water, which will remain in the apparatus, the carbonic acid only being evolved. “As most sorts of soda of commerce contain one or other of the substances (just) named, and as it is far more simple to add at once some chromate of potassa to the soda solution, than to test the latter for either of the three salts, it is always advisable to make it a rule, in the examination of SODA, to add some chromate of potassa.” (Fresenius.)

If the sodium or other carbonate under analysis contains much chloride, the addition of more sulphuric acid than necessary must be avoided, and the carbonic anhydride expelled by gently heating over a warm bath, and not by the addition of excess of acid.

To obviate the difficulties, and to give greater precision and delicacy to volumetrical assays, the instrument known as Mohr’s ALKALIMETER, or Mohr’s BURETTE, and which is figured in the margin, may be employed. By means of it the test-acid in the graduated tube (a) may be added to the alkaline solution in (f), in any quantity at a time, however minute, by merely pressing the handles of the clamp (d) with the thumb and finger. The terminal tube (e) has its lower orifice very small, and it is connected with the burette by means of a small piece of vulcanised india-rubber tube, on which the clamp (d) acts. (See engr.) The inner cylindrical part of the arm (b) is lined with cork, to prevent injury to the glass burette, and to hold it the more firmly.

Generally the alkali in the specimen examined may be in either the caustic or carbonated state, or it may consist of any mixture of caustic alkali, or carbonates; but it is absolutely necessary for accurate results, that it should be free from sulphides, sulphites, and hyposulphites, as sulphuric acid acts upon these substances as well as on carbonates. The presence of chlorides does not interfere with the accuracy of the assay, unless a higher degree of heat is employed than that necessary for the expulsion of the absorbed carbonic acid. The SODA-ASH of commerce generally contains all these substances besides common salt, sulphate of soda, and insoluble matter, which do not interfere. Rough samples of POT-ASHES and PEARL-ASH also generally contain some sulphides, though not a large quantity. Various plans have been proposed to avoid this source of error. The best is that of MM. Fresenius and Will, given above, in which the value of the carbonates is estimated by their yield of carbonic anhydride.

The difference between an assay of a sample of the unprepared alkali and of another which has been treated as above, indicates the quantity of impurities contained in them under the forms just referred to. The presence of these substances in the commercial alkalies may be detected by the following tests:—

Sulphides. The addition of sulphuric acid causes the evolution of an odour like that of rotten eggs. The sample in solution yields a black precipitate with acetate of lead. But the most delicate test is the splendid violet-blue colour with nitro-prusside of sodium.

Sulphites and Hyposulphites. A solution of the alkali, insufficient for saturation, being added to sulphuric acid tinged reddish yellow with bichromate of potash, occasions a greenish tinge (owing to the formation of oxide of chromium), when these are present. Hydrochloric acid added to a clear solution, after some time, causes a turbidity and odour of sulphurous anhydride.

Chlorides yield a copious curdy precipitate with nitrate of silver, soluble in ammonia, and reprecipitated by excess of nitric acid.

The amount of pure caustic alkali in a sample of alkali is best determined by Fresenius’s method, as follows:—The total amount of pure alkali, both caustic and carbonated, expressed in per-cents. of carbonate of soda or carbonate of potassa, is ascertained by any of the usual methods. The apparent quantity of alkali per cent. is then determined, without previous treatment of the sample with carbonate of90 ammonia, by the method of Will and Fresenius (p. 86). The difference between the results indicates the per-centage of dry caustic alkali present; or if the volumetric method be in use, it can be often fairly estimated by adding the first portions of the test-acid very gradually to the sample, carefully observing the effect. When the effervescence at length commences the weight or measure of the test-liquor expended shows the quantity of pure caustic alkali under treatment (nearly). The result depends upon the fact, that little or no carbonic-acid gas is expelled from the liquid on the addition of the test-acid, until the caustic portion is very nearly neutralised.

The quantity of WATER or MOISTURE, per cent., present in an alkaline carbonate, is indicated by the loss of weight which 100 gr. suffer on gentle ignition in a loosely-covered iron dish or platinum crucible. So also with samples containing caustic alkali, except that here the water of hydration (= 1 equiv. = 9) is not expelled from the ‘caustic’ portion, and must therefore be determined by calculation.

Other matters deserving the serious attention of the operator are—hitting the exact point of neutralisation, and—preparing the test-acids of the proper strength. The method of effecting the former correctly has been already referred to in this article, and is also fully noticed under Acetimetry and Acidimetry.

Test-acids may be very simply prepared by gradually diluting concentrated sulphuric acid with water until it is reduced to the proper strength; the dilution being made in a glass vessel containing a ‘hydrostatic bead’ exactly corresponding to the desired specific gravity of the dilute acid. When the proper point is reached, and the mixture has again acquired the normal temperature of 60° Fahr., the bead rises from the bottom of the vessel, and floats about indifferently in the middle of the liquid. The sp. gr. may then he carefully ascertained by means of an hydrometer or a specific gravity bottle; after which the strength must be accurately determined by means of a standard solution of either pure anhydrous carbonate of soda or pure caustic soda. An acid of any given strength or saturating power may also be prepared in the following manner:—49 parts of commercial sulphuric acid (oil of vitriol), sp. gr. 1·825, contain nearly 40 parts or 1 equiv. of anhydrous sulphuric acid; if we, therefore, wish to prepare a dilute acid containing in every 1000 grains weight, or measure, exactly 1 equiv. of hydrated sulphuric acid, we have only to make 49 gr. of such acid up to 100 gr. weight or measure with pure water. After it has recovered the proper temperature, its sp. gr., or rather its saturating power, must be carefully tried, and, if necessary, readjusted. As, however, it very often happens that the oil of vitriol employed is not so strong as that above referred to, it is better first to test its strength with pure anhydrous carbonate of soda, and to calculate the quantity required by the Rule of Proportion. Every 53 gr. of the dry carbonate are equal to 40 gr. of ‘dry sulphuric acid.’ Suppose we find the oil of vitriol to contain only 72% of hydrated acid, then—

or, instead of only 40 gr., fully 55¹⁄₄ gr. will be required, which are to be made up with water to 1000 gr., as before. Finally, the diluted acid must be very carefully re-tested, and if found correct, at once put into a well-stoppered bottle, and labelled, for use. Too much care cannot be taken to ensure the test-liquid, whether for alkalies or acids, being of the proper strength, of which the specific gravity alone is an insufficient proof. In practice, so small a quantity only of test-acid as that referred to above is, of course, seldom made; but as any larger quantities are mere multiples of the smaller one, the necessary proportions to be employed are easily calculated. The common plan is to prepare one or more gallons or quantities of 10 lbs. each, and to preserve the liquid in stoppered green glass ‘Winchester-quart bottles,’ so that it may be always ready for use.

Although, as may be inferred from the text, sulphuric acid is generally used as the standard acid, yet oxalic acid in pure crystals is recommended by M. Mohr, and answers admirably, and is prepared and used exactly in the same manner.91

Grains.	are equivalent to	Grains.
22 Carbonic anhydride (dry).		17 Ammonia (pure or gaseous).
63 Oxalic acid (crystallised).		43¹⁄₂ Carbonate of ammonia (neutral, hydrated).
49 Sulphuric acid (liquid, monohydrated, sp. gr. 1·8485).		59 Sesquicarbonate of ammonia (Ph. L.; translucent, hydrated).
75 Tartaric acid (crystallised).		79 Bicarbonate of ammonia (crystallised).
1000 Dilute sulphuric acid (sp. gr. 1·033).		47 Potassa (anhydrous).
		56 Hydrate of potassa (pure caustic potassa).
Water—gr. measure.		69 Carbonate of potassa (anhydrous).
1000 Dilute sulphuric acid (sp. gr. 1·032).		83 Carbonate of potassa (granulated, commercial).
		87 Carbonate of potassa (crystallised).
		100 Bicarbonate of potassa (crystallised).
		31 Soda (anhydrous).
		40 Hydrate of soda (pure caustic soda).
		53 Carbonate of soda (anhydrous).
		143 Carbonate of soda (crystallised).
		84 Bicarbonate of soda (crystallised).
		83¹⁄₂ Sesquicarbonate of soda (average commercial).
		84 Bicarbonate of soda (crystals, or cryst. powder, free from moisture).
		15 Lithia.
		24 Hydrate of lithia.
		37 Carbonate of lithia.
		76¹⁄₂ Baryta (pure, caustic).
		85¹⁄₂ Hydrate of baryta.
		98¹⁄₂ Carbonate of baryta.
		28 Lime (pure, caustic; i. e. quick-lime).
		37 Hydrate of lime (slaked lime).
		50 Carbonate of lime (chalk; marble).
		20 Magnesia (pure, calcined).
		42 Carbonate of magnesia (dry, neutral).
		48¹⁄₂ Carbonate of magnesia (ordinary commercial).
		52 Stronia (pure, caustic).
		61 Hydrate of strontia.
		74 Carbonate of strontia.

ALKALOID. Syn. Vegetable Alkali, Organic Base; Alkaloïdes (pl., -IDES, or -IDÆ), L.; Alcaloïde, Alcali organique, Fr. In chemistry, a name commonly given to any proximate principle of vegetable origin possessing alkaline or basic properties, however feeble. In its most extended sense the term embraces all organic bases, whether obtained from the animal or vegetable kingdom, or produced artificially. The alkaloids form a numerous and important class of bodies. They exist in nature nearly always in the form of salts, the acid being often, like themselves, peculiar to the plant, or class of plants, in which they are found; whilst the medicinal activity of the latter, in most cases, almost entirely depends on their presence.

Prep. The following general methods of procuring the alkaloids will be found applicable to such as full directions are not given for under their respective heads:—

1. (When the base is insoluble in water, non-volatile, and existing in the plant in an insoluble form.) The bruised plant is boiled or macerated in water acidulated with hydrochloric or acetic acid, and the liquor, after filtration, is neutralised with an alkali (ammonia, potassa, lime, or magnesia); the resulting precipitate is purified by re-solution in dilute acid, digestion with a little animal charcoal, and subsequent crystallisation, or re-precipitation with an alkali; or the first precipitate is purified by dissolving it once, or, if necessary, several times, in boiling alcohol, which yields the pure alkaloid either on cooling or by evaporation.

2. (When the base is insoluble in water, and non-volatile, but existing in the plant as a soluble salt.) The bruised or sliced plant is boiled or macerated in water, and the filtered liquor precipitated and otherwise treated as before.

3. (When the base is soluble in water, and non-volatile.) An infusion made with very dilute acid, hydrochloric or acetic, is concentrated by a gentle heat; and the residual liquor treated with potassa (or concentrated solution of ammonia) and ether conjointly; after repose, the ethereal solution is decanted and evaporated. For those alkaloids which are insoluble in ether (as morphia and cinchonia), the previous process may be adopted.

4. (When the base is both soluble in water and volatile.) The vegetable, in a bruised or divided state, or its extract, is alkalised with potassa and distilled; the distillate is neutralised92 with dilute oxalic or sulphuric acid, and carefully evaporated to dryness; the residuum is next digested in alcohol, and the resulting tincture agitated with potassa and ether, the former being in quantity just sufficient to seize on all the acid; lastly, the ethereal solution thus formed, on careful evaporation, leaves the alkaloid nearly pure. It may be further purified by cautious distillation.

As some of the alkaloids are soluble in excess of the alkaline precipitant, over-saturation should be carefully avoided; or the precipitant may be used under the form of carbonate or bicarbonate. When lime and magnesia are employed, they are boiled for a few minutes with the solution.

Props. Alcoholic or aqueous solutions of the alkaloids generally exhibit an alkaline reaction with vegetable colours. Like the alkalies, also, they combine with acids to form salts which, when dissolved in water, are capable of producing the ordinary phenomena of saline double decomposition. Their taste is usually intensely bitter.

The majority of the natural alkaloids contain carbon, hydrogen, nitrogen, and oxygen, and are, at ordinary temperatures, solid, and not volatile without decomposition. Some natural alkaloids contain carbon, hydrogen, and nitrogen only; these are, for the most part, liquid at ordinary temperatures, and can be distilled without decomposition. The greater number of the artificial alkalies are composed of carbon, hydrogen, and nitrogen; some, however, contain oxygen in addition. Alkaloids have also been obtained artificially, in which nitrogen is replaced by phosphorus, arsenic, antimony, or bismuth. Most of the alkaloids, as they are obtained in the free state, correspond in function to ammonia, NH₃, rather than to the fixed alkalies; that is to say, they form salts by direct union with acids, without elimination of water or any other substance. In order to make them strictly comparable to the fixed alkalies, they require, like ammonia, the addition of water (H₂O) to their formulæ; they may then be considered as hydrates of compound radicles analogous to ammonium.

Physiological action. The alkaloids generally possess great medicinal power; some of them act with terrific energy, and are the most violent poisons with which we are acquainted. Perfectly pure aconitia is about 200 times more poisonous than arsenic, and at least 50 times more poisonous than ordinary medicinal prussic acid. The greater number act on animals in the same way as the plants which produce them, provided they are given in proportionately small doses. Many of them, when judiciously administered, are most valuable medicines.

Pois., Ant., &c. Some of the alkaloids act as narcotic or stupefying poisons; others are classed with the narcotico-acrid poisons, or those which produce both narcotism and irritation of the parts they touch. The general symptoms produced by opium and its preparations may be taken as an example of the former; those from aconite and strychnia, of the latter. In large doses of the greater number, narcotism predominates; in smaller ones, irritation; they are rarely coexistent.—Treatm. No common antidote to the effects of this class of substances has yet been discovered. The only safe treatment, of at all general application, is to immediately clear the stomach by means of a strong and quick-acting emetic (as sulphate of zinc), or the stomach-pump, and to administer copious and continued draughts of astringent vegetable solutions (as of tannin, nut-galls, oak-bark, or what is always at hand—very strong tea or coffee). These may be followed by or combined with a smart purge of castor oil, as soon as the stomach is thoroughly cleared of the poison. M. Bouchardat strongly recommends a solution of iodine, 3 gr., and iodide of potassium, 6 gr., in pure water, 16 fl. oz., in cases of poisoning by OPIUM, ACONITE, COLCHICUM, DEADLY NIGHTSHADE, HEMLOCK, NUX VOMICA, &c., or by the alkaloids obtained from them—ACONITINE, ATROPIA, COLCHICINA, CONIA, MORPHIA, STRYCHNIA, &c., or their salts; but not where foxglove or digitalin has been taken. The stomach having been well emptied by an emetic, the solution is to be given by wine-glassfuls for some time; the vomiting being still encouraged during the early part of the administration of the antidote. In the case of narcotics (as opium, morphia, &c.), this is to be followed by the free use of a strong infusion of coffee. According to Dr Garrod, purified animal charcoal is an ‘excellent antidote’ to many of the alkaloids, including those above enumerated, when taken in poisonous doses; as it not merely absorbs them, but, for the most part, renders them inert. To be serviceable it should be recently prepared and fresh-burnt; and should be given in doses of about an ounce at a time, diffused in warm or tepid water, and frequently repeated. The vomiting which follows its use, owing to the warm water, proves advantageous; but after a sufficient time may be lessened by employing less water, or cooler or even cold water. Drowsiness, if present, may be combated by the subsequent use of strong coffee or tea, as before. We have seen this plan succeed in several cases.—Lesions. These, like the symptoms, vary. In some cases there are redness and inflammation of the stomach and intestines, and turgescence of the vessels of the lungs and brain; in others, these appearances are either slight or wholly wanting. Wherever there has been much cerebral disturbance, traces of congestion are usually discernible.

Detec., Tests, &c. The identification of the pure alkaloids is extremely simple; but their detection, when combined with organic and colouring matters, is a task of considerable difficulty. One or other of the following plans may be adopted for this purpose:93—

1. (Merck.) The matter under examination is digested, for several hours, with concentrated acetic acid, added in sufficient quantity to produce a strongly acid reaction; the fluid portion is then strained from the insoluble matter, and the latter being washed with water acidulated with acetic acid, the mixed liquors are gently evaporated to dryness in a water bath; the residuum of the evaporation is boiled first with rectified spirit, and next with rectified spirit acidulated with acetic acid; the mixed liquors are again evaporated, the residuum redissolved or diluted with distilled water, and carbonate of soda or potassa added to feebly alkaline reaction, and the whole, after evaporation to the consistence of a syrup, set aside to repose for 24 hours; it is now again diluted with water, filtered, and the insoluble portion washed with cold distilled water, and digested with concentrated acetic acid; this last solution is diluted with distilled water, and decoloured with pure blood-charcoal (if it be necessary); the fluid, either at once, or after cautious evaporation, may then be tested for the alkaloids, in the usual manner. The charcoal previously used should also be tested in the way described below. This method answers admirably with all the NON-VOLATILE ALKALOIDS, and may be applied to the stomach and viscera, and their contents, and to food, &c., in cases of poisoning.

2. (Stas.) The suspected matter, in a finely divided state, is digested, at 160° to 165° Fahr., with twice or thrice its weight of strong alcohol acidulated (according to the quantity) with ¹⁄₂ dr. to 2 or 3 dr., or more, of pure oxalic or tartaric acid. After a sufficient time, and when the whole has become quite cold, it is thrown on a filter, and the undissolved portion, after being squeezed dry, is washed with strong alcohol. The mixed and filtered alcoholic liquids are then evaporated at a temperature not exceeding 95° Fahr., and, if no insoluble matter separates, the evaporation is continued nearly to dryness;[19] but if fatty or other insoluble matter separates during the process of concentration, the concentrated fluid is passed through a moistened filter, and the filtrate evaporated nearly to dryness, as before. The residuum is next digested with absolute alcohol, in the cold, the insoluble portion, after filtration, washed with alcohol, and the mixed filtrates again evaporated in the air, or in vacuo. The acid residue is now dissolved in a little distilled water, and bicarbonate of soda added as long as effervescence ensues. To this mixture 4 or 5 times its volume of ether is added, and after lengthened agitation (the bottle or tube being held in a cold wet cloth), the whole is allowed to repose for a short time. A little of the supernatant ether is now removed to a small glass capsule or watch-glass, and allowed to evaporate spontaneously.[19] When this leaves oily streaks upon the glass, which gradually collect into a small drop, which emits, when gently heated, a disagreeable, pungent, and stifling odour, the presence of a LIQUID VOLATILE BASE or ALKALOID is inferred; whilst a solid residue or a turbid fluid with small solid particles floating in it, indicates a NON-VOLATILE SOLID BASE.[20] In either case the blue colour of reddened litmus is permanently restored by the residuum. If no residuum is left on the capsule, some solution of pure soda or potassa is added to the liquid, the whole well agitated for several minutes, and the ether (after repose) decanted; an operation which is repeated with fresh ether a second, third, and even a fourth time. The base, or bases (if any are present), will now be found in the mixed ethereal solution, which is, therefore, tested as before. The presence of an alkaloid being detected, the mixed ethereal solutions are allowed to evaporate spontaneously, care being taken, if a volatile alkaloid be present, to neutralise the liquid with an acid before the final evaporation. The last residuum is then tested for the particular alkaloid present, as before.[21]

This method, according to Stas, answers well for all the ALKALOIDS which are soluble in ether; including—ACONITIA, ANILINE, ATROPIA, BRUCIA, CODEIA, COLCHICINA, CONIA, DELPHIA, EMETINA, HYOSCYAMINE, MORPHIA (?), NICOTIA, PETININE, PICOLINE, SOLANINE, STRYCHNIA, VERATRIA, &c. By means of it Stas found nicotia in the heart-blood of a poisoned dog. With such alkaloids as are, however, only very sparingly soluble in ether (as morphia for instance), the result must, necessarily, be doubtful. To detect these, as well as all the alkaloids which are insoluble in ether, it is, therefore, necessary, as directed by Otto, to add to the alkaline fluid left by the decantation of the ether, sufficient solution of soda to dissolve the morphia, &c. (if any has separated), and after the expulsion of the last traces of the ether by a gentle heat, to add a concentrated solution of hydrochlorate of ammonia, and to allow the mixture to repose for some time in the open air. When MORPHIA is present, it separates under the form of small crystals.[22] Or the alkaline liquor may be diluted with distilled water, and treated with charcoal, and this with alcohol, in the manner noticed under method 4 (below).

4. (Graham and Hoffmann—slightly modified.) 2 or 3 oz. of purified animal charcoal are digested in about ¹⁄₂ gal. of the (neutral or only slightly acid) aqueous fluid under examination, with frequent agitation, for 10 to 12 hours, or longer. The liquid is then filtered, and the charcoal left on the filter is washed twice with cold distilled water. The charcoal94 is then boiled for ¹⁄₂ an hour with about ¹⁄₂ a pint of rectified spirit of 80 or 90%; the ebullition being conducted in a flask having a very long tube, open at both ends, fitted air-tight through the cork, to prevent loss of the alcohol by evaporation. The spirit, which now contains the alkaloid (if any was present in the original liquor), is next filtered whilst hot, and the filtrate is submitted to distillation until the whole of the alcohol is removed. A small quantity (commonly a few drops) of solutions of potassa is then added to the residual aqueous liquor, followed by 1 to 2 fl. oz. of pure ether, after which the whole is well agitated for several minutes, and allowed to repose for a short time. Lastly, the supernatant ether is decanted, and allowed to evaporate spontaneously, when the residuum (if any) left in the capsule may be tested by reagents, as before.

This method was devised for the detection of STRYCHNIA and NUX VOMICA in malt-liquors; but it is equally applicable to the detection of ANY ALKALOID which is soluble in ether. The CHARCOAL TEST may also be employed to detect alkaloids which are insoluble in ether; but then the base must be sought in the aqueous residuum obtained by the evaporation of the alcohol.[23]

The presence of the alkaloids and their salts, in clear solutions, may be thus determined:—

I. (Fresenius).—1. The solution is rendered very slightly alkaline with dilute solution of potassa or soda, added drop by drop:—

b. A precipitate is formed:—solution of potassa or soda is added, drop by drop, until the liquid exhibits a strong alkaline reaction:—

α. The precipitate redissolves; absence of Brucia, Cinchonia, Narcotina, Quina, Strychnia, and Veratria; probable presence of Morphia.

β. Precipitate does not redissolve, or not completely; probable presence of one or more of the first six of the above-named alkaloids:—the fluid is filtered from the precipitate, mixed with either bicarbonate of soda or of potassa, gently boiled nearly to dryness, and treated with water. If it dissolves completely; absence of morphia; an insoluble residue indicates Morphia.

2. The precipitate 1. b. β. is washed with cold distilled water, dissolved in a slight excess of dilute sulphuric acid, neutralised with a saturated solution of bicarbonate of soda, and allowed to repose a few hours:[24]—

a. No precipitate; absence of Cinchonia, Narcotina, and Quina:—the solution is gently evaporated nearly to dryness, and treated with cold water:—if it dissolves completely, pass on to 4; if there is an insoluble residue, it may contain Brucia, Strychnia, or Veratria. (See 3.)

b. A precipitate:—the filtered fluid is treated as directed at 2 a.; the precipitate is washed with cold distilled water, dissolved in a little hydrochloric acid, ammonia is added in excess, and subsequently a sufficient quantity of ether, agitation being had recourse to:—

α. The precipitate formed by the ammonia redissolves completely in the ether, and the clear fluid separates into two layers; absence of Cinchonia; probable presence of Quina or Narcotina.

β. The precipitate produced by the ammonia does not redissolve in the ether, or not completely; probable presence of Cinchonia, and perhaps also of Quina or Narcotina. The filtered liquid may be tested for these alkaloids as at a.

3. The insoluble residuum after the evaporation of the solution 2. a., or of the filtrate 2. b., is now dried in a water bath, and digested with absolute alcohol:—

a. It dissolves completely; absence of strychnia; probable presence of Brucia, Quina (?), or Veratria:—the alcoholic solution is evaporated to dryness, and, if quina has been already detected, the residue is divided into two portions, one of which is tested for Brucia, the other for Veratria.

b. It does not dissolve, or not completely; probable presence of Strychnia, and perhaps also of Brucia and Veratria:—the filtered fluid is divided into two portions, and tested separately as at a.

4. The original liquid 1. a. may contain Salicine, a proximate vegetable principle closely allied to the alkaloids:—a portion is boiled with hydrochloric acid for some time; the formation of a precipitate shows the presence of Salicin. (See 2, below.)[25]

II. (Larocque and Thibierge.) Terchloride of gold is recommended, by these writers, as a more decisive test for the alkaloids than the ‘double chloride of gold and sodium’ commonly employed for this purpose. The following are the colours of the precipitates which it produces with the aqueous solution of their salts:—Brucia, milk-brown, passing into coffee-brown, and lastly chocolate-brown:—CINCHONIA, sulphur yellow:—MORPHIA, yellow, then bluish, and lastly violet; in this last state the gold is reduced, and the precipitate is insoluble in water, alcohol, the caustic alkalies, and sulphuric, nitric, and hydrochloric acid; it forms with aqua regia a solution95 which is precipitated by protosulphate of iron:—QUINA, buff-coloured:—STRYCHNIA, canary-yellow:—VERATRIA, pale greenish-yellow. All these precipitates, with the exception mentioned, are very soluble in alcohol, insoluble in ether, and only slightly soluble in water. Those with morphia and brucia are sufficiently marked to prevent these alkalies from being mistaken for each other; and those with brucia and strychnia are, in like manner, easily distinguishable.

III.—Mr Wanklyn discriminates the different alkaloids from the estimation of the ammonia they evolve. His process is as follows:—A small flask with a lateral tube, and connected with a Liebig’s condenser, is charged with about 25 c. c. of an alkaline solution of permanganate potash made by dissolving 200 grammes of caustic potash and 8 grammes of crystallised permanganate of potash in 1 litre of water. A minute quantity of the alkaloid carefully and accurately weighed is now introduced, and the mixture slowly distilled. The most satisfactory results are obtained by treating from 1 to 5 milligrammes of the alkaloid in this way, but quantities so small as ¹⁄₁₀th of a milligram will in skilled hands give accurate results. The ammonia is formed in the distillate by Nesslerising it, as described under Water analysis. For all practical purposes the poisonous alkaloids may be divided into four classes:

I.
	NH₃ per cent.
Solanine yields half its nitrogen as Ammonia	0·98
II.
Morphia yields half its nitrogen as Ammonia	2·98
Codeine, ditto, ditto	2·87
Papaverine, ditto, ditto	2·50
Veratria, ditto, ditto	2·87
III.
Atropia yields all its nitrogen as Ammonia	5·73
Narcotine, ditto, ditto	4·11
Strychnia yields half its nitrogen as Ammonia	5·09
Brucine, ditto, ditto	4·32
Aconite, ditto, ditto	3·50
Coneine, ditto, ditto	4·60
IV.
Nicotine yields half its nitrogen as Ammonia	10·49

IV. Dr Guy, as well as others, have made researches, having for their object the determination of the exact temperature at which the poisonous alkaloids melt and sublime. A very minute speck of the substance is placed on a porcelain plate or copper disc, and a square or oval of microscope-covering glass is placed over it, supported by a thin ring of glass or any other convenient substance.

Heat is then applied to the plate or copper, and the temperature, as indicated by a thermometer at which the substance fuses or volatilises, is carefully noted.

				Fahr.	Cent.
Cantharidine sublimes as a white vapour without change of form or colour.				212°	100°
		Sublime.		Melt.
		Fahr.	Cent.	Fahr.	Cent.
Morphine	Sublime, melt and yield carbonaceous residue.	330°	165°	340°	171°
Strychnine	Sublime, melt and yield carbonaceous residue.	345°	174°	430°	224°
		Melt.		Sublime.
		Fahr.	Cent.	Fahr.	Cent.
Aconitine	Melt, change colour, sublime, and deposit carbon.	140°	60°	400°	204°
Atropine		150°	66°	280°	138°
Veratrine		200°	93°	360°	182°
Brucine		240°	116°	400°	204°
Digitalin		310°	154°	310°	154°
Picrotoxin		320°	160°	320°	160°
Solanine		420°	215°	420°	216°

Selmi’s method of extracting poisonous alkaloids in forensic investigations. The alcoholic extract of the viscera, acidified and filtered, is evaporated at 65° C., the residue taken up with water, filtered to separate fatty matters, and decoloured by means of basic acetate of lead, leaving the solution in contact with the air for 24 hours. It is then filtered, the lead precipitated by means of sulphuretted hydrogen, and the solution after concentration repeatedly extracted with ether. The ethereal solution is then saturated with dry carbonic anhydride, which generally causes a precipitate of minute drops adhering to the sides of the vessel, and containing some of the alkaloids. The ethereal solution is then poured into a clean vessel, mixed with about half its volume of water, and a current of carbonic anhydride96 passed for about twenty minutes, which may cause the precipitation of other alkaloids not precipitated by dry carbonic anhydride. Usually the whole of the alkaloids present in the ether are thrown down by these means, but if not, the solution is dehydrated by agitation with Barium oxide, and then a solution of tartaric acid in ether added to the clear liquid, taking great care not to employ excess of acid. This throws down any alkaloid that may remain. In order to extract any alkaloids that may still remain in the viscera, they are mixed with Barium hydrate and a little water, and then agitated with purified amylic alcohol; the alkaloids may subsequently be extracted from the alcohol by agitation with very dilute sulphuric acid.

A knowledge of the different solubilities of the alkaloids will be found an important auxiliary in their analysis. The following is a summary of the relative solubility of the most important of them. The figures denote the number of parts of the liquid required for their solution:—

Amylic alcohol.—Solanine (1061); digitalin sparingly soluble; morphine (133); strychnine (122); veratrine, brucine, atropine, aconitine, and picrotoxin, freely soluble.

Benzol.—All the poisonous alkaloids, except solanine, are soluble in benzol.

Chloroform.—Solanine (50,000); morphine (6550); strychnine (8); the rest freely soluble.

Ether.—Solanine (9000); morphine (7725); strychnine (1400); aconitine (777); brucine (440); veratrine (108); atropine, picrotoxin,[26] and digitalin, very soluble.

Water (cold).—Strychnine (8333); veratrine (7860); morphine (4166); aconitine (1783); solanine (1750); brucine (900); atropine (414); picrotoxin (150); digitalin very soluble.

The principal Alkaloids and their Salts, in the state of powder, or with ‘conia’ and ‘nicotia,’ in the state of an oily looking liquid, may be thus distinguished:—

1. a. The powder is treated with nitric acid:—It is coloured red; probable presence of Brucia, Delphia, Morphia, or commercial Strychnia. If the reddened acid becomes violet on the addition of ‘protochloride of tin,’ it is Brucia; if it becomes black and carbonaceous, it is Delphia. If the powder is fusible without decomposition, and strongly decomposes iodic acid, it is Morphia; if it is not fusible without decomposition, and does not decompose iodic acid, it is Strychnia.

b. If instead of a red, the powder strikes a green colour with nitric acid, it is Solania; if it is insoluble in ‘ether,’ and not reddened by ‘nitric acid,’ it is Emetia; if soluble in ether, not reddened by ‘nitric acid,’ but melts and volatilises when heated, it is Atropia; if it is thus affected by ether or nitric acid, but does not volatilise, it is Veratria. (See 2, below.)

2. a. The powder, or (with ‘conia and nicotia’) concentrated liquor, is treated with a drop or two of concentrated sulphuric acid:—A red colour is produced; probable presence of Brucia, Nicotina, Salicine, or Veratria. If the reddened mixture has at first a roseate hue, turning deep red on the addition of nitric acid, it is Brucia; if the original substance moistened with solution of potassa evolves the odour of tobacco, it contains Nicotine; if the red colour produced by the acid is permanent and of an intense blood-hue, and the powder agglutinates into lumps like resin, it is Salicine; if the colour is at first yellowish, changing to blood-red, and ultimately to crimson and violet, it is Veratria.

b. If instead of the substance being ‘reddened’ by strong sulphuric acid, no particular action ensues in the cold, it contains either Conia or Strychnia; if a small fragment of bichromate of potassa being now dropped in, produces a rich violet colour, it is Strychnia; if the original matter on being heated, or treated with solution of potassa, evolves a penetrating, disagreeable odour, somewhat analogous to that from ‘hemlock,’ or to a mixture of those from tobacco and mice, it is Conia.

“Reactions with ceroso-ceric oxide. This oxide exhibits characteristic colours with several alkaloids, especially with STRYCHNINE. When strong sulphuric acid is poured upon strychnine, and then a small quantity of ceroso-ceric oxide added, a fine blue colour is produced, similar to that which strychnine exhibits with potassium bichromate, but much more permanent. The blue colour gradually changes to cherry-red, and then remains unaltered for several days. This reaction is capable of detecting one part of strychnine in a million parts of liquid. Brucine similarly treated acquires an orange-colour, gradually changing to yellow; MORPHINE, olive-brown, finally brown; NARCOTINE, brown cherry red, finally wine-red; CODEINE, olive-green, finally brown; QUININE, pale-yellow; CINCHONINE and THEINE remain colourless; VERATRINE becomes reddish-brown; ATROPINE, dingy yellowish-brown; SOLANINE, yellow at first, finally brownish; EMETINE, brown; COLCHICINE, first green, then dirty brown; ANILINE, after a long time, acquires a blue colour extending from the edges inwards; CONINE becomes light-yellow. Piperine colours the sulphuric acid blood-red, and is turned dark-brown, almost black by the cerium oxide” (Sonnenschein).

“Reactions with picric acid. This acid is a very good precipitant for alkaloids, affording a very delicate test for many of them, and may perhaps also serve for separating them one from another. The precipitation takes place97 even in solutions containing a large excess of sulphuric acid, and is sometimes complete. Precipitated are, BRUCINE, STRYCHNINE, VERATRINE, QUINIDINE, CINCHONINE, and most of the opium alkaloids; not precipitated, MORPHINE, ATROPINE (English), PSEUDO-MORPHINE, CAFFEINE, and all glucosides” (Hager).

The presence of one or more of the alkaloids being shown by any of the preceding methods, a portion of the original clear solution or powder, or of the precipitates or filtrates above referred to, must be treated with their characteristic tests, as given under the individual notices of these articles, so as to set at rest all doubt as to their identity. No single test must ever be relied on as a positive proof. The presence of Brucia, Morphia and Strychnia may be determined in substances which after being mixed with the salts of these alkaloids have undergone the acetous, vinous, or putrefactive fermentation, as shown by Orfila, MM. Larocque and Thibierge, and many other eminent chemists and toxicologists, and confirmed, in numerous cases, by our own experiments. Opium and morphia may thus be readily detected in beer, wine, soup, and milk. A paper by Professor Dragendorf in the ‘American Chemist’ for April, 1876, may be consulted with advantage.

Concluding Remarks. It is a singular fact that none of the organic bases found in plants have yet been formed artificially, although several analogous substances have been thus produced. Closely allied to the alkaloids there also exists an extensive series of neutral proximate principles, which differ from those substances chiefly in the absence of basic properties, and in most of them being destitute of nitrogen. They are usually bitter, and, like the alkaloids, generally represent the active properties of the plants in which they are found; whilst some of them possess considerable medicinal energy. Of this kind are asparagin, elaterin, gentianin, picrotoxin, salicin, &c. These two classes of bodies, though actually distinct, are frequently confounded. See Alkali, Organic Bases, Poisons, Proximate Principles, Vegetables, Nomenclature, &c.; also the individual alkaloids under their respective heads.

ALKALOIDS OF ACONITE. The nature of the active principle of aconite root does not appear to have been satisfactorily determined. Messrs Groves, Wright, and Williams contend that the Aconitum napellus yields an active crystalline alkaloid, which they distinguish as Aconitine, and to which they assign the formula C₃₃H₄₃NO₁₂; they add that additionally the root contains more or less of another active alkaloid, which they term Pseudaconitine, and which is represented by the formula C₃₆H₄₉NO₁₁; they also assert that the extract of the roots contains varying quantities of certain decomposition products resulting from the saponification of the above bases by the acids, which are produced by the breaking up of part of the aconitine. The name of these decomposition products is Aconine and Pseudaconine. Of Aconitum ferox they report that it yields a comparatively large quantity of Pseudaconitine and a small quantity of Aconitine. They further affirm that the so-called aconitine of commerce is a mixture of true aconitine and pseudaconitine with variable quantities of their alteration products, aconine and pseudaconine, and of certain amorphous unnamed alkaloids.

Messrs Paul and Kingzett contest the accuracy of these deductions, and dispute the correctness of the formula given to aconitine. Dr Paul doubts whether the alkaloid to which the active properties of the root are ascribed has ever yet been obtained in an isolated condition. He thinks it probable that the substance obtained from aconite root was to a great extent a salt of an acid, like aconitic acid. For further information the reader is referred to the ‘Pharmaceutical Year Book’ for 1873, 1874, 1875, 1876, and 1877.

AL′KANET. Syn. Anchu′sa, L.; Orcanette, Fr.; Orkanet, Ger.; Or′chanet*, Dyer’s al′kanet, D. bu′gloss*. The anchu′sa tincto′′ria (Willd.; lithosper′mum tincto′′rium—Linn.), a deciduous herbaceous plant, with a perennial, dark blood-red root. Hab. Asia Minor, Greece, Hungary, &c. It is also largely cultivated in the neighbourhood of Montpellier. The dried root (ALKANET ROOT; RADIX ANCHUSÆ, R. A. TINCTORIÆ) is chiefly imported from the Levant. It contains a beautiful blood-red colour, which it freely gives out to oils, fats, wax, spirits, essences, and similar substances, by simply infusing it in them, and is consequently much employed to colour these articles. Wax tinged with it, and applied on warm marble, stains it of a rich flesh-colour, which sinks deep into the stone, and possesses considerable durability. Its spirituous tincture also imparts a deep red to marble.

Prop., &c. The colouring matter of alkanet was regarded by Pelletier as a fatty acid (ANCHUSIC ACID); but it has since been shown to be a species of resin (ANCHUSINE, PSEUDO-ALKANNINE, P.-ALKANIUM). According to Dr John, good alkanet root contains 5¹⁄₂ per cent. of this substance. Anchusine melts at 140° Fahr.; is scarcely soluble in water, to which it only imparts a dirty red colour, but is very soluble in alcohol, oils, and acetic acid. Alkalies turn it blue. It is found wholly in the root-bark. In selecting this article, the smaller roots should therefore be chosen, as they possess more bark than the larger ones, in proportion to their weight. Exposure to ammoniacal fumes, or even handling it much with the fingers, changes its red to a crimson or purplish hue.

Uses, &c. It is much employed by druggists and perfumers to colour oils, lip-salves, plasters, pomatums, &c.; by varnish-makers, to tinge their varnishes and lacquers; by statuaries98 to stain marble; by dairy-farmers, to colour cheese; by wine-merchants and bottlers (in the form of tincture), to stain beforehand the corks of their port-wine bottles, in order to imitate the effects of age, and as colouring and flavouring for factitious port wine; and by dyers, and others. A species of crimson rouge was formerly prepared from it (hence its name).

ALLAN′TOIN. C₈H₆O₆N₄. Syn. Allanto′ic acid*, Amniot′ic a.† Am′nic a.†; Allantoï′na, L. A substance discovered by Vauquelin and Buniva in what they imagined to be the liquor amnii of the cow, and hence named by them amniotic acid. It was afterwards shown by Dzondi and Lassaigne to exist in the fluid of the allantoïs, and not of the amnios. It has since been produced artificially by Wöhler and Liebig.

Prep. 1. The allantoïc fluid of the fœtal calf is evaporated to 1-4th or 1-5th of its volume, and then set aside for some time. The crystals thus obtained are purified by re-solution, digestion with animal charcoal, and re-crystallisation.

2. (Wöhler and Liebig.) Uric acid, 1 part; is dissolved in water, 20 parts; and freshly precipitated and well-washed binoxide of lead is added to the solution until the colour ceases to change; the liquid is next filtered while hot, evaporated until a pellicle forms on the surface, and then set aside to crystallise; the crystals being purified as before.

Prop., &c. Small, but very brilliant prismatic, transparent, colourless crystals; tasteless; neutral; soluble in 160 parts of cold water, and in much less at 212°; nitric acid converts it into ALLANTURIC ACID; oil of vitriol resolves it into ammonia, carbonic acid, and carbonic oxide; hot concentrated solutions of the caustic alkalies change it into ammonia and oxalic acid.

ALLANTOX′ICUM. [L.] Syn. Allantox′icum, L. (prim., Gr.). The poison developed, during putrefaction, in sausages made of blood, liver, &c. “It often proves speedily fatal.” (Kraus.)

ALLGEMEINE FLUSSTINCTUR (Sulzberger, Salzungen). For the relief of a number of diseases, among which are cholera and sea-sickness. Aloes, 1 part; spirit of wine, 2 parts. (Spau.)

ALLIA′CEOUS (-sh′us). Syn. Allia′ceus, L.; Alliacé, Ailiacé, Fr.; Knoblauchartig, &c., Ger. Garlick-like; an epithet applied to substances having the odour or properties of garlic or onions.

ALLIGA′TION. Syn. Alliga′tio, L. In commercial arithmetic, a rule for ascertaining the price or value of mixtures, and for determining the proportions of the ingredients that must be taken to produce mixtures of any given price, value, or strength. The first is called ALLIGATION ME′DIAL; the second, ALLIGATION ALTERN′ATE. Its principles and applications are explained under Mixtures (Arithmetic of).

ALLOP′ATHY. Syn. Allopa′thia, L. (from ἁλλος, other, different, and παθος, affection or disease, Gr.); Allopathie, Fr. In medicine, the method of curing disease by the use of remedies which tend to produce a condition of the system, either differing from, opposed to, or incompatible with the condition believed to be essential to the disease it is sought to cure. It is commonly employed to distinguish the ordinary system of medical practice from homœopathy (which see). Hence (an) ALLOP′ATHIST, and the corresponding adjective ALLOPATH′IC (allopath′icus, L.).

ALLOT′ROPY. Syn. Allot′ropism; Allotro′pia, Allotropis′mus, L. Literally, a difference in character; another form of the same substance. In chemistry, a term invented, by Berzelius, to express the state or condition, or the change of character, assumed by certain substances at different temperatures, or under different treatment, whilst their nature and composition continue the same. It more particularly relates to colour, hardness, solubility, texture, &c. Boron, carbon, silicon, iron, sulphur, and phosphorus, afford striking examples of the changes here referred to.

ALLOX′ANTIN. C₈H₄N₄O₇.3H₂O. A crystallisable substance, first obtained by Dr Prout from uric acid.

Prep. 1. Uric acid, 1 part; is boiled in water, 32 parts; dilute nitric acid being added until solution is complete; the resulting liquid is evaporated to ²⁄₃rds its volume, and then set aside for 10 or 12 hours; the crystals, which are deposited, are purified by re-solution and crystallisation.

2. Sulphuretted hydrogen gas is passed, in a full stream, through a moderately strong aqueous solution of alloxan, in the cold. The alloxantin, which is deposited as a crystalline mass, is purified by draining, cautious washing with cold water, re-solution in boiling water, and re-crystallisation. The impure mother-liquor from which crystals of alloxan have separated, if diluted with water, may be used for this purpose.

Prop., &c. Crystals, small colourless, transparent, four-sided, oblique rhombic prisms; scarcely soluble in cold water; solution reddens litmus; with baryta water it gives a characteristic violet-coloured precipitate, which disappears on heating; and with nitrate of silver a black precipitate of that metal; the crystals are reddened by ammoniacal vapours.

ALLOY′. Syn. Alliage, Fr.; Legirung, Vermischung durch schmelzen, Ger. In coinage, a compound of the precious metals with another, or others, of less value; also the least valuable metal, or metals, in such compounds. In chemistry and metallurgy, combinations of the metals with each other usually obtained by fusion. When mercury is one of99 the component metals, the compound is termed an AMALGAM.

Prep., &c. No General rules can be given for this purpose. Alloys of metals differing greatly in fusibility, are commonly made by adding the more fusible one, either in the melted state, or in small portions at a time, to the other melted, or heated to the lowest possible temperature at which a perfect union will take place between them. The mixture is usually affected under a flux, or some material that will promote liquefaction, and prevent volatilisation and unnecessary exposure to the air. Thus, in melting lead and tin together, for solder, resin, or tallow is thrown upon the surface; in tinning copper, the surface is rubbed with sal ammoniac; and in combining some metals, powdered charcoal is used for the same purpose. Quicksilver combines with many metals in the cold, forming AMALGAMS.

Comp. The following Table exhibits the composition of the more important compounds of this class:—

Names.	Combining metals.
Albata	See German Silver.
Amalgams	Mercury and other metals.
Bath-metal	Copper and zinc.
Bell-metal	Copper and tin.
Brass	Copper and zinc.
Britannia metal	Tin with antimony, copper, and bismuth.
Bronze	Tin and copper.
Bronze aluminium	Copper and aluminium.
Cannon-metal	Tin and copper.
Dutch gold	Copper and zinc.
Fusible metal	Bismuth, lead, and tin.
German silver	Copper, nickel, and zinc, with, sometimes, a little iron and tin.
Gold (standard)	Gold with copper.
Gold (old standard)	Gold with copper and silver.
Gun-metal	See Cannon-metal.
Mosaic gold	Copper and zinc.
Or-molu	Copper and zinc.
Pewter (common)	Tin and lead.
Pewter (best)	Tin with antimony, bismuth and copper.
Pot-metal, Cock-metal	Copper and lead, with, sometimes, a little zinc.
Queen’s metal	Tin with antimony, bismuth, and copper.
Shot-metal	Lead with a little arsenic.
Silver (standard)	Silver and copper.
Solder	Tin and lead.
Speculum-metal	Tin and copper, and arsenic.
Stereotype-metal	Lead, antimony, and bismuth.
Tombac, Red Tombac	Copper and zinc.
Tutania	See Britannia metal.
Type-metal	Lead and antimony.
White copper (Packfong; Whitetombac)	Copper and arsenic.

Prop., &c. Alloys generally possess characteristics unshared by their component metals. Thus, copper and zinc form brass, which has a different density, hardness, and colour to either of its constituents. Whether the metals tend to unite in atomic proportions, or in any definite ratio, is still undetermined. The evidence afforded by the natural alloys of gold and silver, and by the phenomena accompanying the cooling of several alloys from the state of fusion, goes far to prove that such is the case. (Rudberg.) The subject is, however, one of considerable difficulty, as metals and metallic compounds are generally soluble in each other, and unite by a simple fusion and contact. That they do not combine indifferently with each other, but exercise a species of elective affinity not dissimilar to other bodies, is clearly shown by the homogeneity and superior quality of many alloys in which the constituent metals are in atomic proportions. The variation of the specific gravity and melting-points of alloys from the mean of those of their component metals, also affords strong evidence of a chemical change having taken place. Thus, alloys generally melt at lower temperatures than those required for their separate metals. They also usually possess more tenacity and hardness than the mean of their constituents.

Matthiessen found that when weights are suspend to spirals of hard-drawn wire made of copper, silver, gold, or platinum, they become nearly straightened when stretched by a moderate weight; but wires of equal dimensions100 composed of copper-tin (12% of tin), silver-platinum (36% of platinum), and gold-copper (84% of copper), scarcely undergo any permanent change in form when subjected to tension by the same weight.

The same chemist gives the following approximative results upon the tenacity of certain metals and wires hard drawn through the same gauge (No. 23):

		lbs.
Copper		25-30
Tin	under	7
Lead	”	7
Tin-lead (20% lead)	about	7
Tin-copper (12% copper)	”	7
Copper-tin (12% tin)	”	80-90
Gold		20-25
Gold-copper (8·4% copper)		70-75
Silver		45-50
Platinum		45-50
Silver-platinum (30% platinum)		75-80

On the other hand, their malleability, ductility, and power of resisting oxygen is generally diminished. The alloy formed of two brittle metals is always brittle; that of a brittle and a ductile metal, generally so; and even two ductile metals sometimes unite to form a brittle compound. The alloys formed of metals having different fusing-points are usually malleable whilst cold, and brittle whilst hot. The action of the air on alloys is generally less than on their simple metals, unless the former are heated. A mixture of 1 part of tin and 3 parts of lead is scarcely acted on at common temperatures; but at a red heat it readily takes fire, and continues to burn for some time like a piece of bad turf. In like manner, a mixture of tin and zinc, when strongly heated, decomposes both moist air and steam with almost fearful rapidity.

The specific gravity of alloys is never the arithmetical mean of that of their constituents, as commonly taught; and in many cases considerable condensation or expansion occurs. When there is a strong affinity between two metals, the density of their alloy is generally greater than the calculated mean; and vice versâ, as may be seen in the following Table:—

Greater than the mean of their constituents:—		Less than the mean of their constituents:—
Copper and	bismuth,	Gold and	copper,
”	palladium,	”	iridium,
”	tin,	”	iron,
”	zinc,	”	lead,
Gold and	antimony,	”	nickel,
”	bismuth,	”	silver,
”	cobalt,	Iron and	antimony,
”	tin,	”	bismuth,
”	zinc,	”	lead,
Lead and	antimony,	Nickel and	arsenic,
Palladium and	bismuth,	Silver and	copper,
Platinum and	molybdenum,	Tin and	antimony,
Silver and	antimony,	”	lead,
”	bismuth,	”	palladium,
”	lead,	Zinc and	antimony.
”	tin,
”	zinc.

“Every alloy,” says Dr Ure, “is, in reference to the arts and manufactures, a new metal, on account of its chemical and physical properties. A vast field here remains to be explored. Not above sixty alloys have been studied by chemists, out of many hundreds which may be made, and of these very few have yet been practically employed. Very slight modifications often constitute very valuable improvements upon metallic bodies.” See Analysis, Assaying, Brass, Bronze, Electrotype, German Silver, Gold, Metals, Specific Gravity, &c.

ALLU′′VIAL. (-l’ōōv′-yăl). Syn. Allu′′vious*; Allu′′vius, L.; d′Alluvion, Fr. In geology, applied to partial deposits of mud, sand, gravel, &c., left by rivers and floods upon land not permanently submerged beneath water; in agriculture, applied to soils so formed or deposited.

ALLU′′VIUM. [L., Eng.] Syn. Alluvion, Fr.; Anflössung, Anschwemmung, Ger. In geol. and agr., alluvial deposit or soil. See Soils, &c.

AL′LYL (-lĭl). C₃H₅. In chemistry, the radical of the essential oils containing sulphur, as those of assafœtida, garlic, horseradish, mustard, onions, &c., which are either sulphides or sulphocyanides of allyl. Its probable existence was first shown by Captain Reynolds, who succeeded in producing several of its derivatives. It has since been obtained, in a separate state, by the action of sodium upon iodide of allyl. It is an oily substance with a high boiling point.

Allyl, Sulphide of, (C₃H₅)₂S; obtained (artificially) by acting on sulphocyanide of allyl with sulphide of potassium. See Oil of Garlick.

Allyl, Sulphocy′anide of, C₃H₅CNS; obtained by submitting iodide of allyl to the action of sulphocyanide of potassium; or by gently heating a mixed alcoholic solution of sulphide of allyl and bichloride of mercury, with sulphocyanide101 of potassium. See Oil of Mustard (Volatile).

AL′MOND (ah′-mŭnd). Syn. Amyg′dala (also -US, -UM*), L.; Amande, Fr.; Mandel, Ger., Dut., Dan., Swed. The ‘almond-tree’ (amyg′dalus commu′nis—Linn.; Ph. L., E., and D.; Amandier—Fr.), a tree of the nat. ord. Rosaceæ, indigenous to Persia, Syria, and the north of Africa; but also extensively cultivated in southern Europe. The almond-tree is about the size of the peach-tree, which it much resembles in appearance. It is incapable of ripening its fruit in this country, and is, therefore, only grown here for the sake of its beautiful vernal flowers. There are several varieties, of which the most important are the sweet and the bitter, so named from the flavour of the seed or kernel. These, for the most part, resemble each other in appearance. De Candolle (‘Prodromus,’ ii, 530) gives five varieties of this species:—A. AMA′′RA (bitter-almond); A. DUL′CIS (sweet-a.); A. FRAGILIS (tender-shelled a.); A. MACROCAR′PA (large-fruited a., pista′chio a., sultana a.); A. PERSICO′ÏDES (peach a.).

AL′MONDS. Syn. Amyg′dalæ, L.; Amandes, Fr.; Mandeln, Ger. The seed or kernels of the almond-tree. They are met with in commerce both in the shell (AMYG′DALÆ CUM PUTAM′INE, -ĭn-e, L.), and shelled (AMYGDALÆ, L.). In the retail shops, most commonly in the latter form. Those rancid, broken, or worm-eaten should be rejected.

Almonds, Bitt′er. Syn. Amyg′dalæ ama′′ræ, L.; Amygdala amara, Ph. E.; Amandes Amères, Fr.; Bittere mandeln, Ger. A variety imported from Mogadore, chiefly characterised by possessing the bitter flavour, and when rubbed with water, the odour of peach-kernels. They are also smaller and thicker than the sweet almond.

Uses, &c. Bitter almonds are used to relieve the flavour of sweet almonds, to clear muddy water, and to flavour confectionery, liqueurs, &c. By pressure, they yield their bland oil (OIL OF ALMONDS; O′LEUM AMYG′DALÆ, L.); the resulting cake (BITTER-A. CAKE; PLACEN′TA A. AMARÆ, L.) is distilled for the volatile oil (ESSENTIAL OIL OF A.; O. A. A., L.), and is afterwards again pressed into cakes (A.-CAKE), and used to fatten pigs, and for other purposes. Bitter almonds are now seldom employed in medicines, although it is said that they have cured ‘intermittents’ when bark had failed (Bergius), and that their emulsion has been found useful in pulmonary and dyspeptic affections, hooping-cough, and asthma; and externally as a lotion in acne. (Thomson.) In large quantities they are poisonous, and even in the smallest quantities have been known to produce nettle-rash (urticaria) and other unpleasant symptoms. They have long been in repute as an antidote to intoxication. The ancient bacchanals chewed them at their orgies, to lessen the effects of wine, and to enable them to take it in larger quantities with impunity.

Almonds, Blanched′ (blăncht′-). Syn. Amyg′dalæ decortica′tæ, L. Almonds from which the husk or seed-coat has been removed. This is effected by soaking them for a short time in warm water, until the skin can be easily removed by pressure between the thumb and forefinger. They are then peeled, rinsed in cold water, drained, and dried. When intended for the table, the last is effected by wiping them with a soft towel; but when they are intended to be powdered, or kept, they are dried by a very gentle heat in a stove, or in the sun.

Almonds, Burnt′. Syn. Roasted almonds; Almond coffee. Used to colour and flavour liqueurs and confectionery; and formerly, as a substitute for coffee.

Al′monds, In′dian. The fruit of terminalia catappa (Linn.). They are oleaginous, and nutritious; and are used as a substitute for almonds.

Almonds, Ja′va (jāh′-). The nuts or kernels of canarium commune (Linn.). They are eaten, made into bread, and pressed for their oil.

Almonds, Sweet′. Syn. Almonds; Amyg′dalæ, L.; A. dulces, Ph. D.; Amygdala, A. Jordan′ica, Ph. L.; A. Dulcis, Ph. E., & Ph. L. 1836; Amandes, Amandes douces, Fr.; Süsse mandeln, Ger. These are the well-known dessert or table fruit of the name, and are the kind always referred to when ‘almonds’ (simply) are spoken of or ordered.

Comm. var.—1. Jor′dan Almonds, which are the finest, and are imported from Malaga. Of these there are two kinds; the one, above an inch in length, flat, and with a clear brown cuticle, sweet, mucilaginous, and rather tough; the other, more plump, and pointed at one end, brittle, but equally sweet with the former.—2. Valen′tia a. (which come next in quality) are about ³⁄₈ths of an inch broad, not quite an inch long, round at one end, and obtusely pointed at the other, flat, of a dingy brown colour, with a dusty cuticle.—3. Bar′bary and Ital′ian a., which resemble the latter, but are generally smaller and less flattened.—4. A variety, of medium quality, imported in baskets from Spain.

Uses, &c. Sweet almonds are nutritive, emollient, and demulcent; but frequently disagree with weak stomachs. The husk is apt to occasion indigestion and nausea. Owing to a peculiar idiosyncrasy of some habits, dyspepsia, diarrhœa, œdematous swelling of the face, and urticaria (nettle-rash), sometimes, though seldom, follow the use of unblanched almonds. Blanched almonds do not produce these inconveniences, and, therefore, should be preferred for the table. In medicine, almonds are employed chiefly under the form of emulsion, confection,102 &c., and to suspend oily substances in water. Their uses for dietetical purposes are well known. Preparations of them are also employed as cosmetics. The cake left after expressing the oil (ALMOND-CAKE) is used for washing the skin, which it is said to render beautifully soft and clear. See Almond Paste, &c.

AL′NIGHT† (awl′-). A cake of wax with a wick in the midst. The forerunner of, and a rude form of the modern dumpy night-lights called MORTARS.

AL′OE (ăl′-o). Syn. Al′oë (-o-ē), L., Fr. (or ALOÈS), Ger., Ital., Sp., Belg., Dan., Dut., Swed. The aloe-tree. In botany, a genus of plants of the nat. ord. Liliaceæ (DC). The species, of which there are several, are succulent plants or small trees with endogenous stems, and stiff, fleshy, hard, pointed leaves, abounding in a purgative principle (ALOES), which is obtained from them by either evaporating the expressed juice or the decoction. They are all natives of warm climates, and most of them are indigenous to southern Africa.

Hist.

, aehleem (aloe-trees), were known to the sacred historians; and both the plant and the inspissated juice are described by Dioscorides [28] and Pliny.[29]

Uses, &c. In Africa, the leaves of the Guinea aloe are made into ropes, fishing-lines, bow-strings, stockings, hammocks, &c. The leaves of another species are used to catch and hold rain-water. The expressed juice and decoction are also used by the natives as a distaff. (Vide infrà.) Comparative trials, made in Paris, of the strength of cordage and cables formed of hemp, and of the aloe from Algiers, are said to have shown the great superiority of the latter. Fabroni obtained a fine violet colour from the recent juice of the aloe, which has been proposed as a dye for silk.[30]

American Aloe. The agave Americana (Linn.) is a plant unconnected with the preceding, and belonging to the nat. ord. Bromeliaceæ. It is found in all parts of tropical America, and is largely cultivated on the shores of the Mediterranean; and less frequently, as an exotic plant in this country. It grows to the height of about 20 feet, and takes many years to produce its gigantic and magnificent pyramid of flowers; shortly after which it perishes, exhausted, as it were, by its efforts in bestowing its rare beauty on the floral world. The vulgar belief is that it blossoms only once in a century; but, as stated by the late Mr Loudon, it flowers sooner or later according to the culture bestowed on it. Its sap yields a kind of honey (AGAVE HONEY), and by fermentation an intoxicating liquor (PULQUE); desiccated juice, mixed with wood ashes, is used as soap, and lathers either with sea or fresh water; leaf-fibre, used as hemp to make thread and twine.

AL′OE-RESIN. Syn. Resi′na Al′oës, L. The resinous matter deposited by a decoction of aloes as it cools.

Prep. (Ph. L. 1746.) Boil aloes, 1 part, in water, 8 parts, and allow the decoction, strained whilst hot, to repose until the next day; then wash the deposited RESIN, and dry it by a gentle heat. It is probably a mixture of aloine and oxidised extractive.

AL′OES (-ōze). Syn. Bitt′er Aloes‡; Al′oë (-o-ē), L.; Aloès, Suc d’Aloès, Fr.; Aloe, Glausinde Aloe, Ger.[31] The inspissated juice or extract of several species of aloe.

Comp., Prep., &c. Aloes is a complex resinous substance containing a body called aloin, which is its active or purgative principle. It is completely soluble in boiling water, and in alcohol or rectified spirit. The decoction deposits an impure resin or resinoid on cooling.

Phys. eff., Uses, &c. Aloes is a warm stimulating purgative, in doses of 3 to 10 gr.; whilst even 1 or 2 gr. seldom fail to produce one motion without pain or inconvenience. It is considered highly serviceable in hypochondriacal, hysterical, and dyspeptic affections, particularly in phlegmatic habits, and in cases arising from deficiency of bile. As an emmenagogue, and a vermifuge, few medicines are more valuable. It acts on the large intestines, and principally on the rectum; and, therefore, should be administered with caution, or only in small doses, where there is a tendency to prolapsus or piles, and in cases where uterine stimulants (as in pregnancy, &c.) would be improper. “It is remarkable with regard to it, that it operates almost to as good a purpose in a small as in a large dose; and one or two grains will produce one considerable dejection, and twenty grains will do no more, except it be that in the last dose (case) the operation will be attended with griping, &c. It is one of the best cures for habitual costiveness.” (Cullen.) Many of the effects complained of arise from its slow solubility in the primæ viæ, and may be obviated by administering it in a liquid form, or in a solid form combined with soap, which renders it freely soluble in the juices of the stomach.

Aloes is more frequently taken than, perhaps, any known purgative. It enters into the composition of a majority of the aperient medicines prescribed by the faculty, and forms the principal ingredient of nearly all the advertised purgative, antibilious, and universal pills of the nostrum-mongers. The fact of aloetic pills not acting until about 8 to 10 hours after being swallowed—so that if taken on retiring to rest at night they do not generally disturb the patient before the usual time of rising in the morning—has contributed more than anything else to make such remedies popular with parties whose habits or business avocations would be otherwise interfered with.

Aloes is also extensively used in veterinary103 practice. It is the most valuable and reliable purgative for the horse of the whole materia medica; but is less to be depended on for cattle, sheep, and hogs. Barbadoes aloes is the best for this purpose. Cape aloes are, however, often employed, when 1-4th more must be given.—Dose (of the former), for a HORSE, 4 to 8 dr.;[32]—CATTLE, 3 to 6 dr. (followed by a purging drench);—HOGS, 5 to 15 gr.;—SHEEP, 15 to 30 gr.;[33]—DOGS (small ones), 10 to 30 gr., (middle-sized) 20 to 44, or even 60 gr., (large) ³⁄₄ to 1 dr., or even 2 dr.

Aloes is also used in dyeing; and as a colouring matter in stains, lacquers, and varnishes. Aloes, and several of its preparations, are likewise extensively employed to adulterate porter.

Var. These, arranged in the order of their reputed medicinal value, are—Socotrine, Hepatic, Barbadoes, Cape, &c.; and alphabetically, as given below:—

Aloes, Barba′does. Syn. Aloes in Gourds; Al′oë Barbaden′sis, L., Ph. L. & E. Imported from Barbadoes and Jamaica, usually in gourds; sometimes in boxes. The best is the inspissated juice of the cut leaf of aloë vulga′′ris; an inferior quality is prepared from the decoction.—Char., &c. Opaque, lustreless, of a liver colour, a little tending to black, with a bitter nauseous taste, and a very disagreeable odour, especially when breathed on; powder a dull olive-yellow. It is the ‘hepatic’ aloes of most continental writers, and said to be the Αλοη of Dioscorides. It is more active than the other varieties of aloes; but is also more apt to occasion hæmorrhoids, and to gripe, than any of them.

Aloes, Cab′alline (-līne.) Syn. Fœt′id aloes, Horse a.; Aloë caballi′na, A. Guinien′sis, L.; Aloès Caballin, Fr. From aloë In′dica (O’Shaughnessy); or from aloë spica′ta by long and careful boiling. (Lindley.) Used only by farriers. Scarcely known in English commerce.

Aloes, Cape. Syn. Aloë Capen′sis, A. lu′cida (Geiger), L. Imported from the Cape of Good Hope, and obtained from aloë spica′ta, and other Cape species. Odour stronger and even more disagreeable than that of Barbadoes aloes; colour deep greenish-brown; appearance shining and resinous; fracture generally glassy; powder a lively greenish-yellow; almost completely soluble in boiling water, decoction paler than that of other kinds. It is weaker than Barbadoes or even hepatic aloes, and is more apt to gripe, &c., than the latter. A finer kind, known as ‘Bethelsdorp aloes,’ imported from Algoa Bay, is more of a liver colour, and softer than the preceding, and hence often called Cape hepatic-aloes.

Aloes, Hepat′ic. Syn. Bombay’ Aloes*, East-India a.*, Liver-coloured Socotrine a.*; Aloë hepat′ica, Ph. L. & D.; A. In′dica, Ph. E. Imported from Bombay and Madras. It is usually said to be obtained from “uncertain species of aloes;” but it is almost certain that it is “the juice of the Socotrine aloes plant which has been solidified without the aid of artificial heat.”[34]—Char., &c. “Opaque, of a liver colour, bitter taste, and an unpleasant odour.” (Ph. L.) It is less odorous, darker coloured, and more opaque than Socotrine aloes; its powder has also a duller colour, and weak spirit leaves much undissolved matter. Its decoction on cooling frequently deposits a yellow powder. The finer and brighter varieties of hepatic aloes are commonly sold for ‘Socotrines,’ and their medicinal virtues are nearly similar. (See below.)

Aloes, In′dian (various);—1. Deep brown or black, very opaque, and less soluble than ordinary aloes. Scarcely known in commerce.—2. Several varieties ranging in character from ‘Cape aloes’ to ‘hepatics,’ and occasionally to ‘Barbadoes,’ obtained from several species.

Aloes, Mo′cha (-kăh). Syn. Aloë de Mochâ, L. Imported from Muscat. An inferior kind of Indian aloes. (Christison.) It is obtained from the same plant as produces genuine hepatic aloes. (Lindley.) It holds an intermediate position between ‘Cape’ and ‘hepatics,’ but contains much impurity; the latter often amounting to upwards of 25%. Some specimens are, however, of excellent quality. When melted and ‘doctored,’ it is sold for Barbadoes, hepatic, and even Socotrine aloes.

Aloes, Soc′otrine (-trĭn; sŭk′-‡). Syn. Soc′otorine aloes, Smyr′na a., Tur′key a.; Aloë Socotri′na, Ph. L.; Aloë, Ph. L. 1836; A. Socotri′na, Ph. E. “The juice of the cut leaf of uncertain species hardened by the air.” (Ph. L.) Genuine Socotrine aloes is generally supposed to be obtained from aloë spica′ta; but is referred by De Candolle to a distinct species, a. Socotri′na; and by Martius, also to a. purpuras′cens. Formerly this variety was brought from the Island of Socotra or Zocotora (hence the name), by way of Smyrna and Malta; but it is now chiefly obtained from Bombay and Madras.—Char., &c. Colour garnet red to golden red; smell peculiar and aromatic, not unlike a decaying russet apple, especially when fresh-broken, or breathed on, or warmed; taste permanently and intensely bitter; fracture conchoidal; softens in the hand, and becomes adhesive, yet retains considerable brittleness; powder bright golden-yellow colour; central portions of the lumps often soft, especially when first imported. “It is brittle, bitter, of a reddish-brown colour, and an aromatic odour. Light permeates thin recently broken laminæ.” (Ph. L.) “In thin pieces, translucent and garnet red;104 almost entirely soluble in spirit of the strength of sherry. Very rare.” (Ph. E.)

Socotrine aloes are always preferred for medicinal purposes, and are the only variety used in perfumery, varnishes, and other nice purposes in the arts.

Aloes, Strained. Syn. Melted Aloes; Aloë cola′ta, L. Proc. 1. The aloes are melted in a copper pan, by the heat of steam or a water bath, and are then pressed through a strong hair or wire sieve, and allowed to cool.

2. As above, but with the addition of about twice its weight of water; the decoction being strained and evaporated.

Obs. Mocha, Indian, and other common aloes, treated in this way and coloured, are frequently sold for melted or strained ‘Socotrines’ and ‘hepatics.’ The colouring matter usually employed is the precipitated carbonate of iron (sesquioxide), or Venetian red, in very fine powder, with, sometimes, a little annatto. This fraud is not readily detected by mere inspection, by those unaccustomed to these matters; and hence the impunity with which it is perpetrated.

The object in melting aloes is to deprive it of the foreign matters, as sand, leaves, pieces of wood, &c., which the commoner kinds generally contain in large quantities. The action of the heat drives off much of their nauseous smell, at the same time that it deepens their colour, and renders their appearance more translucent and resinous, to the disguise of their original nature. The operation, on the large scale, is usually carried on at night, in consequence of the horribly nauseous fumes evolved, which may be smelt at a great distance, and contaminate the clothes of those engaged in it for a long time afterwards.

AL′OES HEMP. A plant growing in Peru, the East and West Indies, and Mexico (A. Americana, A. vivapara, A. fœtida, &c.), where the leaf is cultivated for its fibre, which is generally of a yellowish-white colour, and used for rope-making.

AL′OES WOOD. Syn. Al′oe-wood; Eaglewood; Agal′lochum (-kŭm), Lig′num al′oës, L. agal′lochi, L. a. ve′′ri, L. aq′uilæ, L. aspal′athi, L.; Agalloche, Bois d’aloès, Fr.; Aloeholz, Ger.; Calam′bac, Calam′bouc, Ind.; Xylo-al′oës†. A name applied to the wood of alöex′ylon agal′lochum (Lam.), a leguminous tree of Cochin China; and, though apparently less correctly, to that of aquila′′ria agallochum and a. ova′ta (Lour.), trees of tropical Asia, belonging to a different nat. order. Both are highly fragrant and aromatic; used in fumigations and pastilles, and occasionally by cabinet makers and inlayers. The essential oil of the wood, dissolved in spirit, was regarded by Hoffmann as one of the best cordials and invigorants known. The same has also been said of a tincture of its resin.

The same name and synonyms are popularly applied to the resin of the above woods (ALOES-WOOD RESIN), of which there are two varieties:—the one, light and porous, and filled with a highly fragrant resinous substance; the other, denser and less resinous. It is an oily concretion in the centre of the tree, the result of disease, which gradually hardens, and, in time, kills it. It is highly fragrant, and is said to be nervine, cephalic, cardiac, and stimulant. The powder is regarded as tonic and astringent. Of all perfumes this is said to be the one most esteemed by oriental nations.

ALOE′TIC. Syn. Aloët′icus, L.; Aloétique, Fr. Of or belonging to aloes. In medicine, pharmacy, &c., applied to any preparation containing aloes as a characteristic ingredient; made or obtained from aloes. Substantively, an aloetic medicine.

AL′OIN (-o-ĭn). C₁₇H₁₈O₇. [Eng., Fr.] Syn. Al′öin; Aloï′na, L. The Messrs T. & H. Smith, of Edinburgh, have applied this name to a crystalline substance, which they assert to be the pure cathartic principle of aloes. Their process is to evaporate to the consistence of a syrup, in vacuo, a solution obtained by exhausting a mixture of aloes and sand, with cold water, and then to set it aside for a few days. The resulting dark crystalline mass is purified by pressure between folds of bibulous paper, and repeated crystallisation from hot water. Barbadoes aloes are commonly used for the purpose; but soft or semi-liquid Socotrine aloes, or the unevaporated Socotrine-aloes juice, is probably its best source. Tilden gives the following process for the preparation of aloin:—The aloes crushed small is to be dissolved in nine or ten times its weight of boiling water acidified with sulphuric acid. After cooling and standing for a few hours, the clear liquid is decanted from the resin, and evaporated. The concentrated solution deposits a mass of yellow crystals, which can be purified by washing, pressure, and recrystallisation from hot spirit. After several recrystallisations the aloin is obtained in the form of beautiful yellow needles, which are pretty soluble in water and in alcohol, but soluble with difficulty in ether.—Dose, 1 to 2 gr.

ALOPE′CIA (-sh′ă). [L.] Syn. Al′opecy, Fox′-evil; Alopécie, Fr.; Fuchsraude, Ger. In pathology, baldness from disease, often extending to the beard and eyebrows; as distinguished from ‘calvities,’ or ordinary baldness arising from attenuation of the scalp or defective nutrition. See Baldness.

ALPAC′A. A species of Llama, popularly known as the Peruvian Sheep, an animal intermediate between the camel and sheep, having long silky hair, nearly as fine as that of the Cashmere goat. It was introduced to the British manufacturers in 1834, when only 5700 lbs. of it was imported; but it soon became an important article of commerce, the quantity imported having gradually risen to105 above 2¹⁄₄ millions of lbs. in 1853; whilst the price has risen from about 9d. to 2s. 7d. the lb., in the same time. The name is also given to fabrics woven from the wool of this animal; and to others in fine wool, made in imitation of them. The gigantic factory, &c., erected at Saltaire, Yorkshire, in 1852, for this manufacture, covers about 12 acres of land. See Llama.

ALPENKRAUTER-BRUST-TEIG (Grablowitz, Gras). Pectoral cakes of Alpine herbs. Gum arabic, 100 parts; sugar, 200 parts; extract liquorice, 1 part; saffron, ¹⁄₈th part. Each box contains 48 lozenge-shaped yellowish cakes. Made into a mass with decoction of marsh mallow. (Hager.)

ALPENKRAUTER GESUNDHEIT’S LIQUEUR (Rudolph Bohl). Medicinal liqueur of Alpine herbs. A bottle containing 350 grammes of a liqueur which is an extract of star anise, cassia, frangula bark, centaury, chicory, gentian, and a little aloes. (Hager.)

ALPENKRAUTER-MAGENBITTER (Hauber). Stomachic bitters of Alpine herbs. A brown liqueur of bitter, spirituous, and slightly aromatic flavour, containing in 100 parts: oil of anise, 0·5; oil of cloves, 0·5; aloes, 1·5; alcohol, 40; water, 50. 157 grammes in each bottle. (Wittstein.)

ALPINE ROSE SOAP, SWISS. A preservative against syphilitic infection (G. A. Sarpe, Zurich). A glass cylinder corked and sealed, about 2 inches long, and containing a hard brownish-grey mass weighing 12 grammes, prepared thus:—Ammonia, 1 part; sublimate, 3 parts; tannin, 2 parts; chloride of lime, 24 parts; Castile soap, 190 parts; oil of cloves, 1 part; spirit of wine, q. s. (Hager.)

AL′QUIFOU (-ke-fōō). Syn. Black lead-ore, Potter’s ore. A native sulphide of lead used by potters to give a green glaze to coarse wares.

ALSTONIA SCHOLARIS. (Ind. Ph.) Habitat. Common in forests throughout India.—Officinal part. The bark (Alstoniæ cortex). It occurs in thick, irregular, more or less contorted pieces, easily broken. It consists of a rough greyish epidermis, investing a buff or pale cinnamon-coloured bark; internally, still lighter in colour, and of a spongy texture, having a very bitter taste, but devoid of odour.—Properties. Astringent, tonic, anthelmintic, antiperiodic—Therapeutic uses. In chronic diarrhœa and the advanced stages of dysentery; also as a tonic in debility after fevers, and other exhausting diseases.—Dose. 3 to 5 grains, either alone or combined, in bowel affections, with small doses of ipecacuanha and extract of gentian.—Preparations. Tincture of Alstonia (Tinctura Alstoniæ). Take of alstonia bark, bruised, 2¹⁄₂ ounces; proof spirit, 1 pint. Macerate for seven days in a closed vessel, with occasional agitation; filter, and add sufficient proof spirit to make 1 pint. Or prepare by percolation, as Tincture of Calumba.—Dose, 1 to 2 fluid drachms.

Alstonia, Infusion of. (Infusum Alstoniæ.) Take of alstonia bark, bruised, ¹⁄₂ an ounce; boiling water, 10 fluid ounces. Infuse in a covered vessel for an hour and strain.—Dose. From 1 to 2 fluid ounces twice or thrice daily. A good serviceable tonic.

AL′TERATIVE (awl′-tĕr-ă-tĭv). Syn. Al′terant*; Al′terans (ăl′-), L.; Altérant, Altératif, Fr. In medicine, having power to alter; applied to substances and agents which occasion a change in the habit or constitution, and thus re-establish the healthy functions of the body, or any part of it, without producing any sensible evacuation or other obvious effect.

ALTERATIVE EXTRACT, or GOLDEN MEDICAL DISCOVERY (Dr Pierce, Buffalo), for the cure of all severe, acute, chronic, or long-standing coughs, inflammations, hoarseness, scrofulous, and syphilitic diseases. A clear light-brown fluid, 220 grms., composed of 15 grms. purified honey, 1 grm. extract of lettuce, 2 grms. laudanum, 100 grms. of proof spirit tasting of fusel oil and wood spirit, and 105 grms. water. (Hager.)

AL′TERATIVES (-tĭvz). Syn. Alteran′tia, L.; Altératifs, &c., Fr. Alterative medicines or agents. The preparations of mercury and iodine, when properly administered, are the most useful members of this class; and are those which are now the most generally employed.

ALTHE′IN (ăl-thē′-ĭn). Syn. Althæ′ina, L. The name given by Braconnot to a substance identical with asparagin, which he discovered in the ‘marsh-mallow’ (althæ′a officina′lis, Linn.).

ALTHOFF WATER (aqua mirabilis), for torpid ulcers. Wine vinegar, 750 parts; sulphate of copper, 100 parts; potash, 25 parts; ammonia, 30 parts; salt of sorrel, 8 parts; French brandy, 375 parts. Digest for a few days in a glass vessel and distil to dryness from a glass retort. (Wittstein.)

AL′UDEL (-ū-). In chemistry, a pear-shaped glass or earthen pot open at both ends, formerly much used for connecting other vessels in the process of sublimation. A number of them joined together are still employed for the distillation of quicksilver, in Spain.

AL′UM K₂SO₄.Al₂(SO₄)₃.24Aq. Syn. Pot′ash-alum, Sul′phate of aluminum and potassium, Common alum; Alu′men, A. potas′sicum, L.; Alun, Sulfate d’alumine et de potasse, Fr.; Alaun, Ger.; Alume, Ital.

The principal alum-works in England, until recently, were those of Lord Glasgow, at Hurlett and Campsie, near Glasgow, and those of Lords Dundas and Mulgrave, at Whitby, Yorkshire (est. 1600); but those of Mr Spence, at Manchester, and at Goole (Yorkshire), and of Mr Pochin, at Manchester, are now among the largest, if they be not actually the largest in106 the world. There are also extensive alum-works at and near Newcastle-on-Tyne; but none of importance, that we know of, in any other part of these realms.

Nat. hist. Alum is found native in some places (NATIVE ALUM), either effloresced on the surface of bituminous alum-schist (Göttwigg, Austria); or united with the soil in the neighbourhood of volcanoes (Solfatara, Naples); when it may be obtained by simple lixiviation and evaporation, a little potash being commonly added to convert the excess of sulphate of alumina present into alum. It is also found in certain mineral waters (East Indies).

Sources. The alum of commerce is usually obtained from schistose pyritic clays, commonly termed alum-ores, aluminous shale, a.-schist, &c.; and from alum-rock, a.-stone, or alunite. At La Tolfa, Civita Vecchia, where the best Roman-alum is produced, the source is stratified alum-stone. On the Continent, and in Great Britain, it is generally pyritaceous clays, volcanic aluminous ores, aluminous shale, or alum-slate. These minerals contain sulphide of iron, alumina, bitumen or carbon, and frequently a salt of potassium. Of late years large quantities of alum have been prepared on the banks of the Tyne from aluminous clay.

Prep. The manufacture of alum is technically said to be conducted according to the natural process when prepared from alum-schist or alum-ore; and according to the artificial process when made by acting on clay with sulphuric acid, and adding a potassium salt to the resulting lixivium. The manufacture of alum and of sulphate of alumina from such materials as contain only alumina, to which consequently sulphuric acid and alkaline salts have to be added, has come largely into practice in England. The materials employed are, in addition to clay, cryolite or Greenland spar, a fluoride of aluminum and soda; bauxite, a hydrate of alumina, of more or less purity; and slag. The following are the details of these processes:—

1. The mineral (alum-ore, a.-schist, &c.) is placed in heaps, and moistened from time to time with water, when it becomes gradually hot, and falls into a pulverulent state. This decomposition commonly occurs either wholly, or partially, on the floor of the mine. If the ore does not possess this property on mere exposure to air and moisture, it is broken into pieces and laid upon a bed of brushwood and small coal, to the depth of about four feet, when the pile is fired and fresh lumps of the alum-mineral thrown on, until the mass becomes of considerable height and size. The combustion, as soon as established, is conducted with a smothered fire, until the calcination is complete; care being taken to prevent fusion, or the disengagement of either sulphurous or sulphuric acid, from contact between the ignited stones and the carbonaceous fuel.[35] To promote these ends the pile, at the proper time, is ‘mantled’ (as the workmen call it) or covered with a layer of already calcined and exhausted ore, in order to protect it from high winds and heavy rains; as also to moderate the heat, and let it proceed gradually, so that the sulphur present may not be lost or wasted by volatilisation. The roasting is finally checked by a thicker ‘mantling,’ and the whole allowed to cool. By this time the pile has usually lost about one half its bulk, and become open and porous in the interior, so that the air can circulate freely through the mass; the latter, in dry weather, as the heap cools, being usually promoted by sprinkling a little water on it, which, by carrying down some of the saline matter, renders the interior still more open to the atmosphere. The whole, when cold, or nearly cold, is, if necessary, still further exposed to the action of air and moisture. The time required to calcine the heap properly, including that taken by the burned ore to cool, varies, according to its size and the state of the weather, from three to nine, or even twelve months. The residuum of the calcination is next placed in large stone or brick cisterns, and edulcorated with water, until all the soluble portion is dissolved out; the solution is then concentrated in another stone cistern, so made that the flame and heated air of its reverberatory furnace sweep the whole surface of the liquor. (See engr.) The evaporation is continued until it just barely reaches the point at which crystals are deposited on cooling; when it is run off into coolers. After the sulphate of iron, always present, has been deposited in crystals, the mother-liquor, containing the sulphate of aluminum, is run into other cisterns, and a saturated solution of chloride of potassium, or of sulphate of potassium, or (sometimes) impure sulphate or carbonate of ammonium, or a mixture of them,[36] is added until a cloud or milkiness ceases to be produced on addition of more.[37] It is107 next allowed to settle and get thoroughly cold, and the supernatant ‘mother-liquor’ being drawn off with a pump or syphon, the precipitate, which is alum in the form of minute crystals (technically termed ‘flour’), is well drained, and subsequently washed by stirring it up with a little very cold water, which is then drained off, and the operation repeated a second time with fresh water. A saturated solution of the pulverulent alum (‘flour’) is next formed in a leaden boiler, and the clear portion is run or pumped off, while boiling hot, into crystallising vessels, called roaching casks (see engr.), the staves of which are lined with lead, and nicely adjusted to each other. After the lapse of a week or ten days, the hoops and staves of these ‘casks’ are removed, when a thick crust of crystallised alum is found, which exactly corresponds in form and size to the interior of the cask. A few holes are then made in the sides of this mass, near the bottom, to allow the contained mother-liquor to drain off, after which the whole is broken up and packed in casks for sale. Sometimes the alum thus obtained, or the lower portion of it, is washed with a little very cold water, and, if discoloured, or small or slimy, is purified by a second crystallisation.

2. As ammonia-alum (Spence’s process; see below), but using a potash-salt as the precipitant, either wholly or in part, instead of ammonia; and, in the latter case, supplementing the deficiency of potash with ammonia, as there explained.

1. Clay, free or nearly free from carbonate of lime and oxide of iron, is chosen for this purpose. It is moderately calcined (in lumps) in a reverberatory furnace, until it becomes friable; great care being taken that the heat be not sufficient to indurate it, which would destroy its subsequent solubility. It is next reduced to powder, sifted, and mixed with about 45% of its weight of sulphuric acid (sp. gr. 1·45), the operation being conducted in a large stone or brick basin arched over with brickwork. Heat is then applied, the flame and hot air of a reverberatory furnace being made to sweep over the surface of the liquor. The heat and agitation are continued for 2 or 3 days, when the mass is raked out and set aside in a warm place for a few weeks (6 to 8), to allow the acid the more perfectly to combine with the clay. At the end of this time the newly-formed sulphate of alumina is washed out, the solution evaporated until of a sp. gr. of about 1·38 (1·24 for ‘ammonia-alum’), and the salt of potash added. The remaining operations resemble those above described. Good alum may be produced by this process at about two thirds the cost of rock or mine alum.

2. (Process of Mr Pochin.) Fine China clay is heated in a furnace, and mixed with a suitable proportion of sulphuric acid; the latter being considerably diluted with water, in order to moderate its action, which would otherwise be far too violent. The mixture is then passed into cisterns furnished with movable sides, where, in a few minutes, it heats violently and boils. The thick liquid gradually becomes thicker, until it is converted into a solid porous mass; the pores being produced by the bubbles of steam which are driven through it, owing to the heat resulting from the reaction of the ingredients on each other. This porous mass (ALUM-CAKE; CONCENTRATED ALUM) appears perfectly dry, although retaining a large amount of combined water. It also contains all the silica of the original clay, but in such a state of fine division, that the whole appears homogeneous; whilst it imparts a dryness to the touch which can scarcely be given to pure sulphate of alumina. From this substance a solution of pure sulphate of alumina is easily obtainable by lixiviation, and allowing the resulting solution to deposit its silica before using it, but for many purposes the presence of the finely divided silica is not objectionable. The sulphate of alumina solution so obtained is adapted to all the purposes in dyeing for which alum is now employed; the sulphate of potash or of ammonia in the latter being an unnecessary constituent, and one merely added to facilitate the purification and subsequent crystallisation of the salt. To obtain ALUM from the porous alum-cake, the proper proportion of acid having been used in its preparation, or subsequently added, it is only necessary to precipitate its concentrated solution with a strong solution of a salt of potash, or of ammonia, or a mixture of them, and to otherwise proceed as before.

Ratio. In the above process the sulphide of iron of the shale or schist is converted by atmospheric oxygen into sulphate of iron and sulphuric acid; the sulphuric acid decomposes the clay, setting silica free, and producing sulphate of aluminum. The sulphate of iron is108 mostly got rid of by concentrating the solution of the mixed sulphates, and the mother-liquors are converted into alum by the addition of the salt of potassium. When chloride of potassium is used, it yields chloride of iron and sulphate of potassium, the latter combining with the sulphate of aluminum, and the former remaining behind in the mother-liquor. See Alums (in Chemistry).

1. (Thomson’s method.) Decomposition of cryolite by ignition with carbonate of lime. From the ignited mass the aluminate of soda is obtained by lixiviation with water, and into the solution carbonic acid gas is passed, when there result precipitated hydrated gelatinous alumina and carbonate of soda, which remains in solution. If it be desired to obtain the alumina as an earthy compact precipitate, bicarbonate of soda is used instead of carbonic acid. While the clear liquor is boiled down for the purpose of obtaining carbonate of soda, the precipitated alumina is dissolved in dilute sulphuric acid; this solution is evaporated for the purpose of obtaining sulphate of alumina (the so-called concentrated alum), or the solution after having been treated with a potassa or an ammonia salt is converted into alum.

2. (Sauerwein’s method.) Decomposition of cryolite by caustic lime by the wet way. Very finely ground cryolite is boiled with water and lime, the purer the better, and as free from iron as possible, in a leaden pan. The result is the formation of a solution of aluminate of soda, and insoluble fluoride of calcium (lime). When the fluoride of calcium has deposited, the clear liquid is decanted, and the sediment washed, the first wash-water being added to the decanted liquor, and the second and third wash-waters being used instead of pure water at a subsequent operation. In order to separate the alumina from the solution of aluminate of soda, there is added to the liquid while being continuously stirred very finely pulverised cryolite in excess, the result of the decomposition being alumina and fluoride of sodium, (soda). When no more caustic soda can be detected in the liquid, it is left to stand for the purpose of becoming clear. The clarified solution of fluoride of sodium is then drawn off, and the alumina treated as above described. The solution of fluoride of sodium having been boiled with caustic lime yields a caustic soda solution, which having been decanted from the sediment of fluoride of calcium is evaporated to dryness. Recently the fluoride of calcium occurring as a by-product has been used in glass-making.

3. The decomposition of cryolite by sulphuric acid yields sulphate of soda convertible into carbonate by Leblanc’s process, and sulphate of alumina free from iron. This method of decomposing cryolite is, however, by no means to be recommended, as owing to the liberation of hydrofluoric acid, peculiarly constructed apparatus are required, whilst the sulphate of soda has to be converted into carbonate.

d. From Bauxite. This mineral, occurring in some parts of Southern France, in Calabria, near Belfast, and in other parts of Europe, consists essentially (viz. 60 per cent.) of hydrate of alumina, more or less pure. In order to prepare alums and sulphate of alumina from it, the mineral is first disintegrated by being ignited with carbonate of soda, or with a mixture of sulphate of soda and charcoal; in each case the lixiviation of the ignited mass yields aluminate of soda, from which, by the processes already described under “Cryolite,” alum, or sulphate of alumina, and soda are prepared.

e. From blast-furnace slag. Lürmann recommends the slag to be decomposed by means of hydrochloric (muriatic) acid. From the resulting solution of chloride of aluminum the alumina is precipitated by carbonate of lime, any dissolved silica being precipitated at the same time. The alumina is dissolved in sulphuric acid, leaving the silica.

Prop. Alum crystallises in regular octahedrons, often with truncated edges and angles; (see engr.); and sometimes in cubes, but only when there is a deficiency of acid in its composition, with the alkali in slight excess of the proper quantity. (Löwel.)[38] It is slightly efflorescent in dry air: soluble in 18 parts of cold water, and in rather less than its own weight of boiling water; tastes sweet, acidulous, and very astringent; is styptic; and reddens litmus. When heated it melts, loses its water of crystallisation, and becomes white and spongy (DRIED ALUM); a strong heat, short of whiteness, decomposes it, with the evolution of oxygen and a mixture of sulphuric and sulphurous anhydride; calcined with carbonaceous matter it suffers decomposition, and furnishes a pyrophoric residuum (Homberg’s pyro′phorus). Ignited with alkaline chlorides, hydrochloric acid is liberated; which also occurs when their concentrated solutions are boiled together. Ammonia precipitates pure hydrate of aluminum from potassium alum; but only a subsulphate from the simple sulphate of alumina. Sp. gr. 1·724; but, when containing ammonia, often so low as 1·710.

Tests, &c. It is easily recognised by its crystalline form, its taste, and by its complete solubility in water. Its aqueous solution gives a white gelatinous precipitate soluble in excess; a platinum wire moistened with the solution imparts a violet colour to the blowpipe flame;109 and chloride of barium gives a white precipitate insoluble in nitric acid.

Pur. When pure, its solution is not darkened by tincture of galls, sulphuretted hydrogen or ferrocyanide of potassium; neither does it give any precipitate with solution of nitrate of silver. Heated with caustic potassa, or quick-lime, it does not evolve fumes of ammonia.

Adult., &c. The principal impurity, and one which renders alum unfit for the use of the dyer, is iron. This may be readily detected by the blue precipitate it gives with ferrocyanide of potassium, or the black precipitate with sulphide of ammonium, which are very delicate tests.[39] Lime, another very injurious contamination, may be detected by precipitating the alumina and iron (if any) with ammonia, and then adding oxalate of ammonia to the boiled and filtered liquid. The liquid filtered from the last precipitate (oxalate of lime) may still contain magnesia, which may be detected by the white precipitate caused on the addition of an alkaline phosphate. Common alum frequently contains ammonia, from urine, or the crude sulphate of the gas-works, having been employed in its manufacture. Powdered alum is frequently adulterated with common salt, in which case it gives a white curdy precipitate with nitrate of silver, turning black by exposure to the light.

Phys. eff. &c. In small quantities alum acts as an astringent; in larger doses as an irritant. It acts chemically on the animal tissues and fluids, is absorbed, and has been discovered in the liver, spleen, and urine (Orfila), the last often becoming acid (Kraus). Externally, it is astringent. The almost general use of alum by the English bakers is one of the most fertile sources of dyspepsia and liver and bowel complaints in adults; and of debility and rickets in children. Bad teeth and their early decay is another consequence of the daily use of alum in our food. The bone matter (phosphate of lime) of bread, instead of being assimilated by the system, is either wholly, or in part, converted into a salt of alumina, which is useless and incapable of appropriation. When alum has been taken in poisonous doses an emetic should be given, followed by warm diluents and demulcents, containing a little carbonate of soda; and subsequently by a purgative.

Uses, &c. The applications of alum in the arts and manufactures are numerous and important. It is used to harden tallow and fats; to render wood and paper incombustible; to remove greasiness from printers’ blocks and rollers; to prepare a paper for whitening silver and silvering brass in the cold; to help the separation of the butter from milk; to purify turbid water; to dress skins; to fix and brighten the colours in dyeing; to make lake and pyrophorus, &c., &c. It is also extensively used for clarifying liquors, and for many other purposes connected with the arts and everyday life. In medicine, alum is used as a tonic and astringent, in doses of 5 to 20 gr.; as a gargle (1 dr. to ¹⁄₂ pint of water); and as a collyrium and injection (10 to 15 gr. to 6 oz. of water). In lead colic, ¹⁄₂ to 1 dr. of alum (dissolved in gum-water), every 3 or 4 hours, is said to be infallible. Powdered alum is frequently applied with the tips of the fingers, in cases of sore throat and ulcerations of the mouth, &c. A teaspoonful of it is said to be one of the very best emetics in croup. (Dr Meigs.) Alkalies, alkaline carbonates, lime, magnesia, acetate of lead, astringent vegetables, &c., are incompatible with it.

Gen. commentary. In addition to the particulars of its manufacture given above, we may add, that the plan of getting rid of the ferric salts there referred to has to some considerable extent been successfully replaced by that of precipitating the alum, instead of the sulphate of iron, by adding alkaline matter to the lixivium. The crystalline precipitate is purified by draining, re-solution, and re-crystallisation; whilst the sulphate of iron and Epsom-salts contained in the mother liquor are obtained by subsequent evaporation and crystallisation; after which a fresh crop of alum may be got from it, by the use of an alkaline precipitant, as before.

In estimating the strength of his solution the alum-maker takes as a standard a measure or sp. gr. bottle capable of holding exactly 80 pennyweights of distilled water. The excess of the weight of liquor, in pennyweights, over 80, or that of water, is called so many ‘pennyweights strong.’ Thus one of 90 pennyweights (90 dwt.) is said to be ‘10 dwt. strong,’ or simply, ‘one of 90 dwt.’ These numbers correspond to 2¹⁄₂ degrees of Twaddle’s hydrometer, and may easily be found by dividing Twaddle’s degrees by 2·5 or 2¹⁄₂; or by multiplying them by 4, and pointing off the right-hand figure of the product for a decimal. The result is in alum-makers’ pennyweights.

By a patent now expired (Weisman’s, 1839) the ferric salts are precipitated by the addition of a solution of ferrocyanide of potassium (prussiate of potash); after which the supernatant clear liquor, which is now a solution of nearly pure sulphate of alumina, is decanted, and evaporated for future operations, until it either forms, on cooling, a concrete mass, which is moulded into bricks or lumps, for the convenience of ‘packing,’ or until it is sufficiently concentrated to be converted into ALUM by the addition of a salt of potash or of ammonia in the usual manner. The product, in each case, is perfectly free from iron. By a like addition of the ferrocyanide to a solution of ordinary sulphate of aluminia or alum, the dyer may himself easily render them free from110 iron, or iron-alum; when, as mordants for even the most delicate colours, they are equal to the very best Roman alum.

Another process has been patented (Barlow & Gore, 1851) for the manufacture of alum from the ash or residue of the combustion of Boghead-coal, which, though hitherto regarded as almost valueless, actually contains about 30% of alumina. It has not, however, been found a convenient material for the purpose.

By the latest and most approved processes the least possible quantity of boiling water or liquor is employed for making the solutions, so that they may crystallise without evaporation, and thus economise fuel; and the mother-liquors of previous operations are constantly employed for this purpose, when possible. Nor is anything which is convertible to use, from the drainage of the heaps, to the liquor and slime of the roaching casks, allowed to be wasted.

By whatever process, or from whatever materials alum is obtained, it is absolutely necessary for the successful and economical conduct of its manufacture, that the precise composition of the mineral or minerals employed should be exactly known. This can only be determined by actual analysis, which should be extended to several parts of the same bed, and particularly to the upper and lower strata, which frequently differ in composition from each other, and thus require different treatment, or may be most advantageously employed in combinations with each other. The necessity of this will be seen by reference to the composition of the following minerals, of which the top contains a larger proportion of iron-pyrites than the bottom, and the two require to be mixed, to equally diffuse the sulphuric acid generated by the calcination, &c., to which they are subjected.

	Whitby, Yorkshire. (Richardson.)
	Top rock.	Bottom rock.
Sulphide of iron (pyrites)	4·20	8·50
Silica	52·25	15·16
Protoxide of iron	8·49	6·11
Alumina	18·75	18·30
Lime	1·25	2·15
Magnesia	·91	·90
Oxide of manganese	traces	traces
Sulphuric acid (SO₃)	1·37	2·50
Potassa	·13	traces
Soda	·20	traces
Chlorine	traces	traces
Coal	4·97	8·29
Water	2·88	·00
Loss	4·60	(?)
	———	———
	100·	100·

	Campsie, near Glasgow. (Ronalds.)
	Top rock.	Top rock.	Bottom rock.
Sulphide of iron (pyrites)	40·52	38·48	9·63(?)
Silica	15·40	15·41	20·47(?)
Protoxide of iron	...	...	2·18
Alumina	11·35	11·64	18·91(?)
Lime	1·40	2·22	·40
Magnesia	·50	·32	2·17
Oxide of manganese	·15	...	·55
Sulphuric acid	...	...	·05
Potassa	·90	...	1·26
Soda	...	...	·21
Carbon or bituminous matter	27·65(?)	28·80	(?)
Coal	...	...	8·51
Water	...	...	8·54
Loss	2·13(?)	3·13	1·59(?)
	———	———	———
	100·	100·	100·

Alum-rock, or alum-stone, is a species of impure alunite, and is not of very common occurrence. That of Tolfa, near Civita Vecchia, according to Klaproth, consists of—

Silica	56·5
Alumina	19·
Sulphuric acid (SO₃)	16·5
Potassa	4·
Water	3·
Loss	1·
	———
	100·

which exhibits an excess of about 3% of sulphuric acid, and about 14% of alumina, more than are requisite to form alum with the 4% of potassa; proportions which, therefore, require to be supplemented with a potassium salt during the process of manufacture. The alum-stone of Mont d’Or contains, according to Cordier, 1·4% of oxide of iron.

The presence of lime in alum-ore is most prejudicial, owing to its affinity for sulphuric acid being greater than that of either alumina or iron. Ores containing it in any quantity are, therefore, unfitted for the manufacture of alum. Magnesia is also prejudicial; but in this case the sulphate of magnesia left in the mother-liquors is not wholly valueless, as it may be crystallised and sold as111 ‘Epsom-salt,’—a thing which is actually done in some English alum-works.

The potash-salt employed by the alum-makers is either the sulphate or the chloride—chiefly the latter; its sources being the waste liquor of soap-works, saltpetre refineries, and glass-houses. Wood-ashes, although rich in potash, do not answer well unless freed by lixiviation from the large amount of carbonate of lime which is always present in them.

The ammonia-salt used in making alum is generally the crude sulphate prepared from the ammoniacal liquor of gas-works, or that from the manufacture of sal-ammoniac by the destructive distillation of animal matter. Both these liquors may be used without previous conversion into sulphate of ammonia whenever there is an excess of sulphuric acid in the aluminous solution.

Soda-salts are seldom, if ever, used as precipitants in the manufacture of alum, on account of the easy solubility of the resulting SODA-ALUM—a property which unfits them for this purpose. See Alums, Ammonia, Dyeing, Mordants, Potash, Sulphuric Acid, &c. (also below).

Alum, Ammonia. (NH₄)₂SO₄ . Al₂(SO₄)₃ . 24 Aq. Syn. (Alumen; Alum; B. P.), Alu′men Ammonia′tum, L.; Alun d’ammoniaque, A. ammoniacal, Fr. This is an alum in which the sulphate of potassium is replaced by an equivalent of sulphate of ammonium. It is prepared by adding crude sulphate of ammonium to solution of sulphate of aluminum; or gas-liquor, putrid urine, &c., to the acid-sulphate.

Much of the common alum, especially that prepared on the Continent, contains both potassium and ammonium; and recently enormous works for its manufacture have been established in England. As an astringent, and as a source of alumina in dyeing, it resembles potash-alum (i. e. ordinary alum). It may, however, be readily distinguished from the latter by the fumes of ammonia which are evolved when it is moistened and triturated, or heated, with caustic potassa or quick-lime; and by the residuum of its exposure to a white heat being pure alumina. See Alum (antè).

Alum, Basic. A variety of alum found native at Tolfa. On calcination and subsequent lixiviation it yields ordinary alum. A like substance falls as a white powder, when newly precipitated alumina is boiled in a solution of alum.

Alum, Dried; Alum, Burnt. Syn. Alu′men us′tum, A. exsicca′tum (B. P.); Alun Sec, Fr.; Gebrannter alaun, Ger.; Alume calcinato, Ital. Alum deprived of its water of crystallisation by heat.

Prep. Take of alum, 4 oz. Heat the alum in a porcelain dish or other suitable vessel, till it liquefies, then raise and continue the heat, not allowing it to exceed 400°, till aqueous vapour ceases to be disengaged, and the salt has lost 47 per cent. of its weight. Reduce the residue to powder, and preserve it in a well-stopped bottle.

Prop., &c. Similar to those of common alum, but it is rather more astringent, and is less soluble. When moistened, or placed in contact with water, it resumes its water of crystallisation with evolution of heat.—Dose, 10 to 20 gr.; in colic (especially painters’ colic), hæmoptysis, &c. It is chiefly used as an escharotic, to destroy ‘proud flesh,’ &c. It must be kept in a stoppered bottle.

Alum, I′ron (-ŭrn). Syn. Alu′men Fer′ricum, Sul′phas fer′ri et potas′sæ, Fer′ri perox′idi potassio-sul′phas, &c., L.

Prep. Take of peroxide of iron, 9 lbs.; sulphuric acid 14 lbs.; dissolve, dilute the mixture with water, q. s., and add of potassium sulphate, 10 lbs.; evaporate, and crystallise.

Prop., &c. Crystals, beautiful octahedrons of a pinkish or pale violet colour. It is strongly recommended, by Dr Tyler Smith, as a chalybeate tonic, and has been used by him, at St. Mary’s Hospital with marked success. It has also been used as a mordant, in dyeing black.—Dose, ¹⁄₂ gr. to 5 gr.

Alum, Ro′man. Syn. Red alum*, Roach A., Roche A., Rock A.*; Alu′men Roma′num, A. ru′brum, A. ru′peum, &c., L.; Alun Romain, A. de roche, Fr.; Alume di rocca, It. In small fragments, covered with a reddish powder (ALUMEN RUBRUM VE′′RUM); originally imported from Civita Vecchia, where it occurs native. It is much esteemed by dyers from being nearly free from iron-alum. That now sold for it in England is ordinary alum coloured with Venetian red, Armenian bole, or rose-pink (ALUMEN RUBRUM SPU′′RIUM). This is done by shaking the fragments in a sieve over a vessel of hot water, and then stirring them up with the colour, until the surface is uniformly tinged with it. In genuine roach-alum the colour not only covers the surface, but also partially pervades the substance of the crystals. The name was formerly also applied to a pure white variety of alum, prepared at Tolfa; but it is now, in English commerce, exclusively given to common alum artificially coloured.

Alum, Saccharated. Alum, 6 oz., white lead 6 drms., sulphate of zinc 3 drms., sugar 1¹⁄₂ oz. Mix the ingredients reduced to powder into a paste, with vinegar and white of egg. Used in eye waters and cosmetic washes.

Alum, So′da. Syn. Sulphas aluminæ et sodæ, L. Comp. Na₂SO₄ . Al₂(SO₄)₃ . 24Aq. An alum in which the potassium sulphate of common alum is replaced by a like salt of sodium. It does not occur in commerce. (Vide suprà et infrà.)112

ALUM MOR′DANTS. In dyeing, mordants having for their basis either common alum or the acetate or sulphate of aluminum. See Alums and Mordants.

AL′UM-ROOT. Syn. Amer′ican san′icle; Heu′chera (Ph. U. S.), L. The root of heuchera America′na (Linn.), a plant of North America. It is powerfully styptic and astringent; and is used chiefly as an external application in cancer.

AL′UMS. Syn. Alu′mina (pl. of alu′men), L. In chemistry, a term applied to a series or group of salts having potassium alum for their type, which they resemble in crystalline form and constitution.

It is found that the aluminum of common alum may be replaced by any other metal having a like nature, without affecting the leading characteristics of the salt; and further, that in the newly formed compound, as in potassium-alum, the second sulphate may also be replaced under the like conditions. All the alums crystallise in octahedrons or cubes, and they all contain the same number of molecules of water. The alums of commerce (or alums proper) all contain aluminum sulphate and an alkaline sulphate.

Prep. All the alums may be made by mixing together solutions of the respective sulphates in equivalent proportions, when crystals may be obtained by evaporation in the usual manner. The presence of sulphuric acid, in slight excess, assists their crystallisation.

AL′UMED (al′ŭmd). Mixed or impregnated with alum. In dyeing, mordanted with alum.

ALU′MEN (-l′ōō-). [L.] Alum; the pharmacopœial name of alum. (See above.)

ALUMINOUS. In mineralogy, of, resembling, or containing aluminum. In chemistry, containing or obtained from alum.

ALUMINUM. [Eng., Fr., L.] Syn. Aluminium, Eng., Fr., L.; Alumium, Ger. A metallic radical or element very abundantly distributed, united with silica. Discovered by M. Wöhler, who succeeded in obtaining it as a grey metallic powder (A.D. 1827); and later (1845), under the form of globules exhibiting the leading characteristics of the metal. In 1854, M. Dumas announced to the ‘Academy of Sciences,’ that M. St. Clair Deville had procured pure aluminum from clay, and exhibited several specimens of considerable size and beauty. The result was a general impression that it might be easily obtained in any quantity, and ultimately at a reasonable price; expectations which have been only partly, though to a great extent fulfilled, owing to the expense and trouble of the process, notwithstanding recent improvements.

Prep. (M. Deville; A.D. 1854-59.)—A quantity of chloride of aluminum, varying from 200 to 300 grammes (say from 6 to 10 oz.), is introduced into a wide glass or porcelain tube, between two plugs of asbestos to retain it in position, and a current of hydrogen (thoroughly dried by passing first through concentrated sulphuric acid, and then through a tube containing fused chloride of calcium) passed over it; a gentle heat being at the same time applied to the part of the tube containing the chloride, to drive off any free hydrochloric acid which might have been formed by the action of the air upon it. A small porcelain boat, containing sodium, is now introduced at the other extremity of the glass tube, which is then again closed; and when the sodium is fused, the chloride is sufficiently heated to cause its vapour to come into free contact with it. A powerful reaction ensues, with the evolution of much heat, and this continues as long as any undecomposed sodium remains to act on the passing vapour. The mass in the boat, which is now a mixture of the double chloride of aluminum and sodium, in which small globules of the newly reduced metal are suspended, is allowed to cool in the hydrogen; after which it is treated with water, to remove the soluble double chloride. The residuum, consisting of small globules of aluminum, is, lastly, reduced to a solid button or mass, by fusion, at a strong heat, under a layer of the fused double chloride of aluminum and sodium.

On a large scale two cast-iron cylinders are employed, instead of the glass or porcelain tube just referred to; the anterior one of which contains the chloride of aluminum, and the posterior one a tray holding the sodium, of which 10 or 12 lbs. are commonly operated on at once. These cylinders are united by means of a smaller intermediate one, filled with clean scraps of iron, which serve to separate iron, free hydrochloric acid, and chloride of sulphur, from the vapour of the chloride of aluminum, as it passes through them. During the passage of the vapour of the chloride this smaller cylinder, or tube, is kept heated to from 400° to 600° Fahr.; but the two other cylinders are only very gently heated, since the chloride is volatilised at a comparatively low temperature, and the reaction between it and the fused sodium, when once commenced, usually generates sufficient heat for the completion of the process.

Occasionally a mixture of the double chloride of aluminum and sodium, 40 parts; chloride of sodium 20 parts; fluor spar, 20 parts; each separately dried, powdered, and then blended together; sodium, in small pieces, 7¹⁄₂ to 8 parts, are used instead of the last.

It is likewise made from a mixture of cryolite and fused chloride of potassium, of each, in powder, 5 parts; sodium, 2 parts; a cast-iron crucible being employed; the resulting minute globules being collected and fused to a button under a layer of the double chloride of aluminum and sodium.113

Prop., &c. Aluminum, when quite pure, closely approaches silver in appearance, except in being rather less white and lustrous than that metal. Ordinary specimens, called pure, have a slight bluish tint or tin-white colour, with a perfect lustre, but far inferior to that of pure silver. Sp. gr. 2·56, which by hammering may be raised to 2·67. It is both ductile and malleable; fuses at a temperature between the melting-points of zinc and silver; is not affected by either damp or dry air, or by oxygen at ordinary temperatures, or by water whether cold or boiling; even steam, at a red heat, is only slowly decomposed by it. It is not acted on by nitric acid, however concentrated, unless boiling, and then very slowly; nor by dilute sulphuric acid, sulphuretted hydrogen, and the sulphides, or even the fused hydrates of the alkalies. It is, however, readily dissolved by hydrochloric acid, with the evolution of hydrogen, even in the cold; and by a concentrated mixture of nitric and sulphuric acid. It is feebly magnetic, conducts electricity about eight times better than iron, and is more electro-negative than zinc. Commercial specimens, owing to the presence of iron and silicon, and often zinc, usually slowly tarnish in damp air, and possess the other properties described above in a somewhat diminished degree.

In a finely divided state, particularly in the state of powder or minute scales in which it was originally obtained, when heated to redness, it catches fire and burns with great rapidity in the air, and in oxygen gas with intense brilliancy, the product in each case being alumina.

Aluminum unites with the other metals, forming ALLOYS, of which some promise to be of great value in the arts. An alloy of 100 parts of aluminum with 5 parts of silver may be worked like the pure metal, but is harder and susceptible of a finer polish, whilst its property of not being affected by sulphuretted hydrogen and acids remains unimpaired; even 3% of silver is said to be sufficient to impart to it the full brilliance and colour of pure silver. An alloy containing 10% of gold is softer and scarcely so malleable as the pure metal. With 8% of iron, or 10% of copper, it still remains tough and malleable; but a larger proportion of either of these metals renders it brittle.

The presence of 2 or 3% of zinc destroys its ductility and malleability, and also impairs its colour and lustre; whilst less than even ¹⁄₄% of bismuth renders it brittle in a high degree. Small quantities of aluminum added to other metals change their properties in a very remarkable manner. Thus, copper alloyed with 10%; of aluminum has the colour and brilliancy of gold, is harder than bronze, very malleable, and may be worked at high temperatures easier than the best varieties of iron; and with 20% is quite white, and closely resembles silver. With more than 12% of aluminum the alloy is harder, but brittle. The alloy formed of 100 parts of silver with 5 parts of aluminum is as hard as the silver of our coinage, whilst the other properties of the latter metal remain unaltered.

Uses. The valuable properties of aluminum adapt it to numerous applications in the arts and everyday life. Hitherto these have been very limited, owing to its comparatively high price; which, notwithstanding it has fallen considerably, is still sufficient to prevent its general or even extensive application. The ‘eagles’ of the French army have been made of it, as well as certain articles of jewelry, plate, &c., as brooches, bracelets, chains, spoons, and other ornamental and useful objects. Owing to its low sp. gr., it has been used as a suitable material for the minute decimal weights of chemists, for military helmets, trumpets, &c. A few cornet-à-pistons, for which its lightness and sonorousness admirably adapt it, have actually been made of it. Its power of resisting oxygen, sulphuretted hydrogen, moisture, &c., would render it invaluable as a coating to metals, particularly iron and lead, to protect them from rust or corrosion, did not its price intervene. As an internal coating for water-pipes, cisterns, &c., no other substance, except gold and platinum, is so well adapted. In chemistry, capsules, tubes, &c., either made of or coated with it, may be often advantageously substituted for those of platinum.

In addition to what has been said above, it may be observed that, in preparing aluminum, the chief care should be to avoid accidents or failure by the employment of too high a temperature, and to avoid the product being contaminated with other metals or with carbon. To ensure the purity of the metal is a matter of the greatest difficulty, owing to the facility with which foreign matters are taken up, during the process, from the materials of which the apparatus is composed; and from the substances from which it is prepared being seldom absolutely pure. Indeed, it is not too much to assert that chemically pure aluminum has not yet been obtained; and that even a very close approximation to it is of very rare occurrence. Whenever a copper boat is used to hold the sodium, the product is always contaminated with copper. Chloride of aluminum always contains some of the chlorides of iron and silicon, both of which are volatile, and probably takes up a further portion from the porcelain or earthenware used to form the apparatus. Sodium also is seldom uncontaminated with carbon or some compound of it; in which case, and likewise when it is not carefully freed from the naphtha in which it has been preserved, the product always contains carbon. The crucible, whether of porcelain or iron, in which the final fusion is made, also contributes to contaminate the metal. Hence the inferior whiteness and brilliancy of commercial specimens of aluminum; a metal which, in its absolutely pure state, may be114 reasonably inferred to be as superior in the above respects to silver as silver is to tin. Commercial aluminum contains from 88 to 94 per cent. only of pure aluminum, and from 1 to 4 per cent. of iron, ¹⁄₂ to 3 per cent. of silicon, and from 1 to 6 per cent. of copper.

Aluminum salts are generally colourless, soluble, and crystallise with difficulty, and are distinguished as follows:—

Tests.—1. Ammonia and the alkaline carbonates throw down a bulky white precipitate (hydrate of aluminum) from solutions of its salts, which is insoluble in excess of the precipitant.—2. Pure potassa and soda throw down white gelatinous precipitates, freely soluble in excess of the precipitant; from which the hydrate of aluminum is reprecipitated by chloride of ammonium, even in the cold:—3. Phosphate of ammonium gives a white precipitate—4. Iodide of potassium produces a white precipitate, passing into a permanent yellow:—5. Sulphuretted hydrogen gives no precipitate:—6. Sulphydrate of ammonium precipitates alumina from these solutions:—7. Bisulphate of potassium, added to concentrated solutions, gives a precipitate of octahedral crystals of alum:—8. At a red heat its salts part with some of their acid; at a white heat, most of it, if not all:—9. Aluminum compounds, ignited on charcoal before the blowpipe, and afterwards moistened with a solution of nitrate of cobalt and again strongly ignited, give an unfused mass, which, on cooling, appears blue by day, and violet by candlelight; a test, however, which is inapplicable to fusible compounds of aluminum, and such as are not free, or nearly free, from other oxides.

Aluminum, Acetate of. Syn. Acetate of Alumina. Prep. Pure hydrate of aluminum is digested, to saturation, in strong acetic acid, in the cold; and the resulting solution, after being filtered or decanted, is either evaporated by a very gentle heat to a gelatinous, semi-solid consistence (its usual form), or is preserved in the liquid state. By spontaneous evaporation it may be obtained in long, transparent crystals.

Red liquor. From alum, in powder, 4 parts; warm water, q. s. to dissolve; acetate of lead, in powder, 3 parts; the solution and mixture being effected by lengthened agitation in a tub or other wooden vessels, and the clear liquid, after repose for a sufficient time, decanted or drawn off from the sediment.

From alum, 2 parts; (dissolved in) warm water, q. s.; solution of pyrolignite of lime (20° Baumé), 3 parts; as before, but allowing a longer time for the subsidence of the precipitate, and taking more care in the decantation than when acetate of lead is employed.

By decomposing a solution of crude sulphate of alumina with neutral or monobasic acetate of lead.

Prop. Its characteristic property is the feeble affinity existing between its acid and base, which, when it is used as a mordant, is counterbalanced by that of the fibres of the cloth or yarn to which it is applied. In other respects it resembles the other simple salts of alumina.

Uses, &c. In dyeing and calico printing, as a mordant. In medicine, properly diluted, in chronic diarrhœa; and, mixed with syrup of poppies, in slight cases of hæmoptysis (spitting of blood). It has been employed by M. Gannal as an injection to preserve animal bodies, which it will do for years.—Dose, ¹⁄₂ to 1 dr. daily, in divided portions, taken in thin mucilage or syrup, or in barley-water; as an injection, 10 to 20 gr., to water, 4 to 6 fl. oz., in gonorrhœa, leucorrhœa, &c.

Aluminum, Chloride of. Al₂Cl₆. Syn. Sesquichlo′′ride of Aluminum; Alumin′ii Chlori′di, &c., L. Prep. A thick paste made of dry precipitated alumina, lampblack, and oil, is strongly heated in a covered crucible until all the organic matter is carbonised. The residuum is transferred to a porcelain tube fixed across a furnace, one end of which is connected with another tube containing dry chloride of calcium, and the other end with a small tubulated receiver. The porcelain tube is then heated to redness, whilst chlorine, dried by passing through the chloride-of-calcium tube, is transmitted through the apparatus. In one or two hours, or as soon as the tube is choked, the whole is allowed to cool, and the newly-formed SESQUICHLORIDE collected and preserved in mineral naphtha for use.

On the large scale:—Chlorine, dried as before, is passed over a mixture of pure clay, lamp-black, and coal-tar, contained in an iron retort, similar to that used in the manufacture of coal-gas (previously ignited by means of a suitable furnace), and connected with a cool chamber accurately lined with tiles of earthenware. The vapours of the SESQUICHLORIDE condense in this chamber, as a yellowish crystalline mass, which is collected and preserved as before.

Prop., &c. It is volatile at a dull red heat; excessively greedy of moisture; and very soluble, with decomposition, hydrochloric acid and alumina being formed. Once dissolved, it cannot be again recovered. Its chief use is in the preparation of aluminum.

Obs. Although alumina, like magnesia, is freely soluble in hydrochloric acid, the sesquichloride of aluminum contained in this solution cannot be obtained in the anhydrous state, or even the solid form, by its evaporation; the chloride suffering decomposition, with the formation of hydrochloric acid, which is volatilised, and alumina, which is left behind.

Aluminum, Ni′trate of. Al₂(NO₃)₆. Syn. Nitrate of Alumina; Alu′minæ Ni′tras, L. Prep. Similar to that of the acetate and citrate. Its concentrated acid solution deposits rhombic crystals, containing 18 equiv. of water.115

Aluminum, Oxide of (Al₂O₃), and Hydrate of (Al₂(HO)₆). Syn. Alumina.

Prep. Aluminum is precipitated as a hydrate from solutions of aluminum salts on the addition of an alkali or alkaline carbonate; and this precipitate, after being thoroughly washed and dried, on ignition loses its water and becomes anhydrous. The following are the best formulæ for the purpose:—

Alum is dissolved in about 20 times its weight of distilled water, and the solution is dropped slowly into pure solution of ammonia, until the latter is nearly but not entirely saturated, when the whole is set aside for some time. The clear supernatant liquid is then decanted, and the precipitate is carefully and thoroughly washed three or four times with tepid distilled water; after which it is collected on a filter, again well washed with water, and, lastly, pressed and dried between bibulous paper, either without heat, or at a temperature not higher than 120° Fahr. The product is pure hydrate of ammonium, and is converted into anhydrous alumina by exposure to a white heat in a covered crucible. The residuum, after ignition, is pure ANHY′DROUS ALUMINA, or SESQUIOX′IDE OF ALUMIN′UM.

A solution of alum is slowly added to a solution of carbonate of ammonia, avoiding excess; and the resulting precipitate, after being washed and pressed, is dried at a heat of from 120° to 180° Fahr.

Prop., &c. A soft white powder. The hydrate is freely soluble in the acids and in solution of caustic potassa and soda (from which it is precipitable by sal ammoniac); when anhydrous (as after ignition), it is scarcely acted on by acids, and when perfectly indurated, or crystallised, it is wholly insoluble; but on ignition with alkalies, alkaline ALU′MINATES are formed, and the alumina is then readily dissolved by acids, forming salts, which are mostly colourless, non-volatile, and soluble; they have a very astringent and somewhat sweetish taste, redden litmus paper, and lose their acids by ignition. Its most remarkable, or rather useful property, is its strong affinity for the fibres of organic bodies, as cotton, flax, silk, wool, &c., which are capable of taking it from its salts; and also for organic colouring matters. Hence its great use in dyeing, and in bleaching liquids and the preparation of lakes. Hydrate of aluminum agitated or digested with liquids containing vegetable colouring matter, combines with the latter, and either entirely, or to a great extent, removes it from the solution.

Moist precipitated alumina, dried at a heat between 70° and 80°, contains above 58% of water; dried at 212° Fahr., about 32% of water.

Estim. Aluminum is weighed as oxide, after ignition. The solubility of the moist or recently precipitated hydrate in solution of ammonia enable us to separate it from the ALKALINE EARTHS which, when present, are thrown down with it.

Uses, &c. The moist hydrate is used in several processes in the arts. It is the base of cobalt-blue, the lake-pigments, &c. In medicine, it is employed as an antacid and astringent, in acidity of the stomach, cholera, diarrhœa, and dysentery; in which it is said to be superior to the other absorbent remedies. (Ficinus.) It has also been highly recommended in the vomiting and diarrhœa of infancy. (Durr; Neumann; Weese; &c.)—Dose. Children 3 to 10 gr.; adults, 5 or 6 to 20 or even 30 gr., three to six times daily, suspended in water, by mucilage or simple syrup.

Aluminum, Sil′icate of. Al₂(SiO₂)₃. Syn. Sil′icate of Alumina. A substance which, in its hydrous form, is the chief and characteristic ingredient of common clay; and which also occurs, in combination, in several other important and abundant minerals.

Aluminum, Sul′phate of. Al₂(SO₄)₃. Syn. Sesquisul′phate of Alumina, Neutral s. of a., Alu′minæ sul′phas, A. sesquisul′phas, L. Prep. 1. Saturate dilute sulphuric acid with hydrate of aluminum, gently evaporate, and crystallise.

2. (Crude, commercial.) By mixing clay and oil of vitriol, in the way described under Alum. The product is the ‘concentrated Alum’ of the dyers.

Prop. Its crystals are needles and thin pearly plates; soluble in 2 parts of water; taste astringent, and somewhat sweetish; reaction acid; a full red heat expels its acid, leaving a residuum of pure alumina; with the sulphates of potassium, sodium, and ammonium, it forms alum.

Uses, &c. In the arts, chiefly as a substitute for alum; the sulphate of potassium in the latter, being found to be an unnecessary and costly ingredient, only useful to purify the salt from iron, by forming a compound of easy crystallisation; an object that may be effected with greater certainty by cheaper methods. In medicine, as a wash for foul and ill-conditioned ulcers; and as an astringent and antiseptic injection. M. Gannal has successfully employed a solution of this salt to preserve animal bodies, by throwing it into the arteries. Even an enema of 1 quart of it, or an injection of a like quantity into the œsophagus, will suffice to preserve a body for several weeks. The mineral called Al′unite or Alu′minite, found near Newhaven (Sussex), is a native subsulphate or basic sulphate (DISUL′PHATE) of alumina.

Aluminum, Sulphide of. Al₂S₃. Syn. Sul′phide of Aluminium, &c. A substance best obtained by passing the vapour of bisulphide of carbon over pure alumina, at a bright red heat. It is instantly decomposed by water, with the evolution of sulphuretted hydrogen. See Aluminum (above).

Aluminum Tann′ate. Syn. Tannate of Alumina, Eng.; Alu′minæ tann′as, L. Prep. Take of pure hydrate of aluminum (dried at 90°116 Fahr.), 1 part; tannic acid (dried at 212°), 2 parts; triturate them together for some time, adding just sufficient water to bring them to the consistence of a syrup, and carefully evaporate to dryness at a heat not higher than 120° Fahr.; lastly, reduce the residuum to powder.

Uses, &c. A combination of certain constitution, which is said to have been found very useful in obstinate vomiting and diarrhœa, in dysentery, and particularly in hæmoptysis, hæmorrhage, &c.—Dose, 3 to 12 or 15 gr.

AL′VINE (-vĭn). Syn. Alvi′nus, L.: Alvin, Fr. Of or from the belly or intestines; relating to the intestinal secretions.

AM′ADOU (-ăh-dōō). Syn. German tinder, Touch′wood, Pyrotech′nic sponge, Spunk‡§, Surgeon’s Ag′aric, A. of the oak, &c.; Agar′icus quer′cûs, A. quer′nus, A. Chirurgo′′rum, Fun′gus quer′cûs, &c., L.; Amadou, Agaric Amadouvier, Fr.; Zunderschwamm. Ger. A soft, spongy, combustible substance, being the prepared flesh of bole′tus fomenta′′rius (Linn.), an indigenous species of fungus found on the oak, birch, and a few other trees (REAL AMADOU or OAK-AGARIC); for which b. ignia′′rius (Linn.), a like fungus, found on the willow, cherry, plum, and other trees, is frequently substituted.

Collec., Prep., &c. The outer bark of the fungus (collected in Aug. or Sept.) having been removed with a knife, the inner spongy substance is carefully separated from the woody portion lying below, and after being cut into slices, is well beaten with a mallet until sufficiently soft and pliable. Sometimes it is first boiled in water, in order to separate the epidermis and porous parts, and to free it from soluble matter; after which it is beaten as before. In this state it is used in surgery, &c. To complete its manufacture for TINDER, it is soaked once, or oftener, in a strong solution of saltpetre (RED AMADOU; BROWN A.); or in a thin paste made of gunpowder and water, which is thoroughly forced into the pores (BLACK A.); after which it is dried, and well rubbed to free it from loose matter. The first is the more cleanly; the last the more combustible.

Uses, &c. A light brown or reddish-brown substance. In surgery, pharmacy, &c., it is used to stop local bleeding, to spread plasters on, as a compress, and for other like purposes. When covered with resin-plaster it forms an excellent article for the protection of abraded surfaces. A small piece thus prepared, of a circular shape, having a round hole cut in the middle, the size of the apex of the corn, is one of the very best corn-plasters known; as from its great softness it at once protects the part from pressure, and removes the cause. As a material for shoe-socks it is superior to all other substances. The amadou for surgical purposes must not contain nitre.

AMAL′GAM. [Eng., Ger.] Syn. Amal′gama, L.; Amalgame, Fr. In chemistry and metallurgy, an alloy containing quicksilver; more particularly one in which that metal plays a conspicuous part. Medallists improperly apply this term to all soft alloys.

Mercury unites with many of the metals by mere contact; and with some of them, as gold, silver, tin, and lead, in certain proportions, without losing its fluidity. In a few cases, as with potassium, this union is attended with considerable violence, and with the production of light and heat.

Prep. Most of these compounds may be formed by agitating or rubbing the mercury with the other metal, or metals, in the state of filings or small fragments, either with or without heat; or with the easily fusible metals, by adding it to them in the melted state; care been taken, in both cases, that the heat be not sufficient to volatilise the mercury.

Prop., Uses, &c. Some amalgams are solid, and not unfrequently crystalline; others are fluid. Of the latter several crystallise after a time, becoming solid; being, probably, merely solutions of the solid amalgams in excess of mercury. The amalgams of gold, silver, tin, zinc, &c., are extensively employed in gilding, silvering and dentistry, and in other useful arts and manufactures.

Amalgam, Ammonium. An unstable compound produced when a globule of mercury is placed in a small cavity formed in a piece of sal ammoniac, and the negative pole of a powerful galvanic battery is brought into contact with the metal, and the positive pole, with the ammoniacal salt. In a few seconds the new compound (ammonium amalgam) of the consistence of butter is formed. On withdrawing the influence of the battery, the whole returns to its former condition. By putting an amalgam of sodium into the moistened cavity of the sal ammoniac, similar results are obtained. The phenomena attending the formation of this new substance have been urged as evidence of the existence of the theoretical basic radicle AMMONIUM.

Amalgam, Elec′trical. Prep. 1. Take zinc and grain-tin, of each, 1 oz.; melt them in an iron ladle, remove it from the fire, and add of mercury (hot), 3 oz.; stir the whole well together with an iron rod, pour it into a well-chalked wooden box, and agitate it violently until cold; or, instead of this, it may be briskly stirred until cold, and then powdered. It should be preserved in a corked glass bottle.

2. (La Baumé.) Zinc, 2 oz.; grain-tin, 1 oz.; bees’ wax, ¹⁄₂ oz.; melt, add of mercury, 6 oz., and otherwise proceed as before. Preferred by some to all other mixtures.117

Use. To cover the cushions of electrical machines. A little of the powder is poured on a piece of paper, crushed smooth with a flat knife, and then spread thinly on the surface of the cushion or rubber, previously slightly smeared with tallow; or the powder may be rubbed down with a little tallow, prior to the application of it.

Prep. Take of grain-gold, 1 part; mercury, 8 parts; put them into a small iron saucepan, or ladle, and apply a gentle heat, using a smooth piece of iron as a stirrer; when the solution or combination is complete, pour it out on a clean plate or smooth stone slab.

Use. To gild brass, copper, &c., in the common process of wash or fire-gilding. A less proportion of gold than the above is used when a thin and cheap gilding is required; as by increasing the quantity of the mercury the same weight of the precious metal may be extended over a much larger surface.

Amalgam, Sil′vering.—a. For METALS. Syn. Amalgam of silver. Prep., Uses, &c. As the last, but substituting silver for gold.

b. For GLASS. Prep. 1. Lead, tin, and bismuth, of each, 1 oz.; bees’ wax or resin ¹⁄₄ oz.; melt, skim off the dross, cool to the lowest point at which the mixture will remain liquid, and add of quicksilver 10 oz.; mix well with an iron rod.

2. Lead and tin, of each, 1 oz.; bismuth, 2 oz.; quicksilver, 4 oz.; as the last.

Uses, &c. For silvering the insides of hollow glass vessels, globes, convex mirrors, &c. The glass being thoroughly cleaned and dried, is carefully warmed, and the amalgam, rendered fluid by a gentle heat, is poured in, and the vessel turned round and round, so as to bring the metal into contact with every part which it is desired to cover. At a certain temperature it will be found to readily adhere to the glass. The excess is then poured out, and the vessel set aside to cool.

Amalgam, Var′nisher’s. Prep. Melt grain-tin, 4 oz., with bismuth, 1 oz.; add quicksilver, 1 oz., and stir till cold; then grind it very fine with white-of-egg or with varnish, and apply the mixture to the figure or surface with a soft brush. It is used in several of the ornamental trades.

Amalgamating Salts. Boil a solution of pernitrate of mercury with excess of equal parts of powdered persulphate and perchloride of mercury, and decant the liquid portion of the result for use. Chiefly used for amalgamating the zinc plates of galvanic batteries, also as a substitute for mercury in gilding by the amalgam process.

AMAL′GAMATED. Syn. Amalgama′tus, L.; Amalgamé, Fr. Compounded or blended with quicksilver; formed into an amalgam.

AMALGAMA′TION. [Eng., Fr.] Syn. Amalgama′tio, L.; Verquicken, Ger. The act or process by which an amalgam is formed; hence loosely, the mixing or blending of different things. In the art of the refiner, the operation of separating gold and silver from their ores by means of mercury.

AM′ANDINE (-dēne). Prep. 1. (Transparent.)—a. Fine new white or pale honey, 4 oz.; white soft-soap (prepared from lard and potassa), 2 oz.; mix thoroughly in a marble mortar, adding 1 or 2 teaspoonfuls (if necessary) of solution of potassa, until a perfectly homogeneous paste or cream is produced; then rub in, by degrees, and very gradually, of oil of almonds, 7 lbs. (or q. s.), previously mixed with essential oil of almonds, 1 oz.; essence (oil) of bergamot, ³⁄₄ oz.; oil of cloves, ¹⁄₂ oz.; and balsam of Peru, 3 dr. The product, which should have a rich, transparent, jelly-like appearance and behaviour, is, lastly, put into pots for use or sale.

b. (G. W. S. Piesse.) Simple syrup, 4 oz.; white soft-soap (see above), 1 oz.; oil of almonds, 7 lbs. (previously scented with—); essential oil of almonds and bergamot, of each 1 oz.; oil of cloves, ¹⁄₂ oz.; the whole being mixed, &c., as before. Both the above are of very fine quality. Glycerin, in the proportion of about ¹⁄₂ oz. to each lb. of the products, added with the soap, improves their softening quality.

2. (Opaque.)—a. From white potash-soap and gum-mucilage (thick), of each 3 oz.; new white honey, 6 oz.; and the yelks of 5 large eggs; well mixed together, and afterwards intimately blended first, with oil of almonds (scented as before, or at will), 2 lbs.; and afterwards, with thick pistachio-milk (made of the fresh-peeled nuts and rose-water), 5 fl. oz.

b. From almond-paste, honey, white potash-soap, and glycerin, of each. 1 oz.; yelk of 1 egg; oil of almonds, ¹⁄₂ pint (holding in solution—); essential oil of almonds, 1 dr.; balsam of Peru, ¹⁄₂ dr.

Uses, &c. To whiten and soften the skin, and to prevent it chapping. A small portion, about half the size of a filbert, with a few drops of warm water, produces a very white and rich lather, with which the hands and face are lightly rubbed, and the skin, in a short time, gently wiped with a small napkin, whilst the water on it is still milky.

The manufacture of AMANDINE is a matter of some difficulty and labour. The details essential to success are given under Emulsines. It is sometimes coloured, which is done by infusing or dissolving in the oil, before using it, a little—spinach-leaves, for GREEN; and palm-oil, or annatto, for YELLOW and ORANGE. A beautiful SCARLET or CRIMSON tinge may be given to it by a little liquid rouge or carmine (ammoniacal), added just before removing it from the mortar. See Emulsines, Olivine, Paste, 118&c.

AMANITINE. Syn. Amanitina, L. The name given by Letellier to the poisonous principle of amani′ta muscaria, and some other species of fungi. It is brown, uncrystallisable, and soluble.

AMARANTH. Syn. Amaranth′us, L.; Amarante, Fr. The flower love-lies-bleeding (amaranthus caudatus—Linn.). In poetry, an imaginary flower that never fades. (Milton.) In chromatics, a colour inclining to purple.

AMARYTH′RINE. A bitter principle found, in certain lichens, associated with erythrine (which see).

AMASI. This, the native name given by the natives of Central Africa to sour milk, which they prepare by adding to the new milk, a small quantity of milk previously allowed to become sour. The milk thus acidified is considered by them far more wholesome than new milk.

AMAUROSIS. Syn. Gutta serena, Suffusio nigra. A diminution or total loss of sight, arising from paralysis of the retina or optic nerve.

AM′BER. Syn. Elec′tron, Gr.; Elec′trum, Suc′cinum (Ph. D.), L.; Ambre, Succin, Fr.; Bernstein, Ger.; Lynx-stone†, La′pis lyn′cis†, L. A well-known yellowish, semi-transparent, fossil resin, of which trinkets and the mouth-pieces of pipes are commonly made.

Nat. hist., &c. Amber is found in detached pieces on the sea-coast, and is dug up in diluvial soils. That of commerce comes chiefly from the southern coasts of the Baltic, where it is cast ashore between Königsberg and Memel; and from Ducal Prussia, Saxony, Poland, Sicily, and Maryland (U.S.), where it is dug out of beds or mines. It has also been found on the shores of Norfolk, and small pieces are occasionally dug up in the gravel pits round London. It is probably an antediluvian resin; and when found on the coast, is supposed to be disengaged, by the action of the sea, from neighbouring beds of lignite or fossil coal. Much diversity of opinion for a long time prevailed amongst naturalists and chemists as to the origin of amber, some referring it to the vegetable, others to the mineral, and some even to the animal kingdom; its natural history and analysis affording something in favour of each. The vegetable origin of amber has, however, been recently shown by various facts, and is now generally admitted. According to Sir David Brewster, its optical properties are those of an indurated vegetable juice. (‘Ed. Phil. Journ.,’ ii.) Insects and fragments of vegetables are frequently found imbedded in it; and this in a manner which could only have occurred when the resin was a viscid fluid. Microscopical researches have led to the conclusion that it is the production of some species of pine, closely allied to the pinus balsamea. (‘Entom. Trans.,’ i & ii.)

Manuf. Amber is WORKED in a lathe, POLISHED with whiting and water or rottenstone-and-oil, and FINISHED OFF by friction with flannel. During the operation the pieces often become hot and electrical, and fly into fragments; to avoid which they are kept as cool as possible, and only worked for a short period at a time. The workmen are said to often suffer considerably from electrical excitement. Amber is JOINED and MENDED by smearing the surface of the pieces with linseed or boiled oil, and then strongly pressing them together, at the same time holding them over a charcoal fire, or heating them in any other convenient way in which they will not be exposed to injury. The commoner varieties are HARDENED and rendered CLEARER, either by boiling them in rape oil for about 24 hours, or by surrounding the pieces with clean sand in an iron pot, and exposing them to a gradually increasing heat for 30 or 40 hours. During this process small fragments are kept in the sand at the side of the pot, for the purpose of occasional examination, lest the heat be raised too high, or be too long continued.

Prop., &c. Hard; brittle; tasteless; glossy; generally translucent, but sometimes opaque, and occasionally, though rarely, transparent; colour generally yellow or orange, but sometimes yellowish-white; becomes negatively electric by friction; smells agreeably when rubbed or heated; fracture conchoidal and vitreous or resinous; soluble in the pure alkalies, and, without decomposition, in oil of vitriol, which then becomes purple; insoluble in the essential and fixed oils without long digestion and heat; soluble in chloroform; melts at about 550° Fahr.; burns with a yellow flame, emitting at the same time a peculiar fragrant odour, and leaving a light and shiny coal. By dry distillation it yields inflammable gases, a small quantity of water, a little acetic acid, a volatile oil (OIL OF AMBER; O′LEUM SUC′CINI, L.) at first pale, afterwards brown, thick, and empyreumatic, and an acid (SUCCIN′IC ACID; ACIDUM SUCCIN′ICUM, L.); with residual charcoal 12 to 13%. Sp. gr. 1·065 to 1·09, but usually about 1·070. It cannot be fused without undergoing more or less chemical change.

Ident. Amber may be known from mellite and copal, both of which articles are occasionally substituted for it, by the following characteristics:—1. Mellite is infusible by heat, and burns white:—2. A piece of COPAL, heated on the point of a knife, catches fire, and runs into drops, which flatten as they fall:—3. Amber burns with spitting and frothing, and when its liquefied particles drop, they rebound from the plane on which they fall (M. Haüy):—4. Neither mellite nor copal yields succinic acid by distillation; nor the agreeable119 odour of amber when burnt; nor do they become so readily electric by friction.

Uses. It is chiefly made into mouth-pieces for pipes, beads for necklaces, and other ornaments and trinkets. It is also used as the basis of several excellent varnishes. In medicine, it was formerly given in chronic coughs, hysteria, &c.—Dose (of the powder), 10 to 60 gr.

Remarks. The finer sorts of amber fetch very high prices. A piece 1 lb. in weight is said to be worth from 10£ to 15£. 5000 dollars a few years since were offered in Prussia for a piece weighing 13 lbs., and which, it was stated by the Armenian merchants, would fetch from 30,000 to 40,000 dollars in Constantinople. It is more valued in the East than in England; and chiefly on account of the Turks and other Orientals believing it to be incapable of transmitting infection. In the royal cabinet, Berlin, there is a piece weighing 18 lbs., supposed to be the largest ever found. The coarser kinds alone are employed in medicine, chemistry, &c.

Amber, Bal′sam of. Syn. Bal′samum suc′cini, L. The thick matter left in the retort after the rectification of oil of amber; and which it resembles in its properties.

Amber, Facti′′tious (-tĭsh′-). Syn. Suc′cinum facti′′tium, L. Mellite, copal, and anime, have each been substituted for amber, especially for small fragments of it. Recently an imitation has been produced by acting on gutta percha with sulphur, at a high temperature, which, either alone or in combination with copal, is said to have been extensively passed off for genuine amber.

Amber, Sol′uble. Prep. Fragments of amber are cautiously heated in an iron pot, and as soon as it becomes semi-liquid, an equal weight of pale boiled linseed-oil, previously made hot, is very gradually stirred in, and the whole thoroughly blended. Used as a cement for glass and earthenware, and thinned with oil of turpentine to make varnishes. It will keep any length of time if preserved from the air.

AM′BER-TREE. The popular name of a species of anthospermum, an evergreen shrub, of which the leaves, when bruised, emit an agreeable odour.

AM′BERGRIS (-grĭs; grēse‡). Syn. Grey amber*; Ambragri′′sea (grĭzh′-e-ă), L.; Ambregris, Fr.; Ambra, Ambar, Ger. An odorous, solid substance, found floating on the sea in tropical climates, and in the cæcum of the cachalot or spermaceti whale (physeter macrocephalus). It has been supposed by some to be a morbid secretion of the liver or intestines, analogous to biliary calculi; but according to Mr Beale, it consists of the mere indurated fæces of the animal, perhaps (as suggested by Brande and Pereira) somewhat altered by disease. “Some of the semifluid fæces, dried with the proper precautions, had all the properties of ambergris.” (Beale.) It is occasionally found in masses weighing from 60 to 225 lbs.

Prop., &c. Solid, opaque, ash-coloured, streaked or variegated, fatty, inflammable; remarkably light; highly odorous,[40] particularly when warmed, cut, or handled—the odour being peculiar and not easily described or imitated, of a very diffusive and penetrating character, and perceptible in minute quantities; rugged on the surface; does not effervesce with acids; melts at 140° to 150° Fahr. into a yellowish resin-like mass; at 212° flies off as a white vapour; very soluble in alcohol, ether, and the volatile and fixed oils. It appears to be a non-saponifiable fat, analogous to cholesterine. Sp. gr. 0·780 to 0·926.[41]

Pur. From the high price of genuine ambergris it is very frequently, if not nearly always, adulterated. When quite pure and of the best quality, it is—1. Nearly wholly soluble in hot alcohol and ether, and yields about 85% of ambreine:—2. It almost wholly volatilises at a moderate heat, and when burnt leaves no notable quantity of ashes; a little of it exposed in a silver spoon melts without bubble or scum; and on the heated point of a knife it is rapidly and entirely dissipated:—3. It is easily punctured with a heated needle, and on withdrawing it, not only should the odour be immediately evolved, but the needle should come out clean, without anything adhering to it (Normandy):—4. The Chinese are said to try its genuineness by scraping it fine upon the top of boiling tea. “It should dissolve (melt) and diffuse itself generally.” Black or white is bad. The smooth and uniform is generally factitious.[42]

Uses, &c. It is highly prized for its odour, which is found greatly to improve and exalt that of other substances; hence its extensive use in perfumery. In medicine it was formerly given as an aphrodisiac, in doses of 3 to 10 gr. “A grain or two, when rubbed down with sugar, and added to a hogshead of claret, is very perceptible in the wine, and gives it a flavour, by some considered as an improvement.” (Brande.)

Ambergris Facti′′tious. An article of this kind, met with in the shops, is thus made:—Orris-powder, spermaceti, and gum-benzoin, of each, 1 lb.; asphaltum, 3 or 4 oz.; ambergris,120 6 oz.; grain-musk, 3 dr.; oil of cloves, 1 dr.; oil of rhodium, ¹⁄₂ dr.; liquor of ammonia, 1 fl. oz.; beaten to a smooth hard mass with mucilage, and made into lumps whilst soft. This fraud is readily detected.

AM′BREINE (-bre-ĭn). Syn. Ambrei′na, L.; Ambreine, Fr.; Ambarstoff, Ger. The fatty, odorous principle of ambergris.

Prep. Digest ambergris in hot alcohol (sp. gr. 0·827) until the latter will dissolve no more, then filter. The AMBREINE will be deposited as the solution cools, in an irregular crystalline mass, which may be purified by recrystallisation in alcohol.

Prop., &c. Melts at about 90°; volatilises at 212° to 220° Fahr.; nitric acid converts it into AMBREIC ACID. It closely resembles cholesterine.—Prod. 85%.

AMBROSIA, RING’S VEGETABLE (Tubbs, Peterborg, U.S.). A liquid with a sediment, containing 1 per cent. of lead. (Chandler.)

AMEISEN BALSAM. Von Dr Livingstone (Ahnelt, Charlottenburg). Balsam of ants. Castor oil, 72 grms.; balsam of Peru, 2 grms.; bergamot, 5 drops. (Hager.)

AMERICAN PILLS (A. H. Boldt, Lexington). For full-blooded, corpulent persons, and for those of sedentary habits, for irregular menstruation, and against contagious diseases. Made of scammony, rhubarb, and soap. (Schädler.)

AMERICAN MEDICINES, Dr SAMPSON’S (New York). Two kinds of pills of coca:—No. 1. 85 pills composed of coca extract and coca powder, and each pill containing about 0·006 grm. of a morphia salt. No. 2. 50 pills, also of coca, and each containing 0·05 grm. of powdered iron. Both kinds are rolled in lycopodium. (Hager.)

AMERICAN SCHAMPOO-FLUID FOR PROMOTING THE GROWTH OF THE HAIR. Spirit of wine and rum, with some carbonate of ammonia and potash.

AMERICAN DROPS FOR TOOTHACHE (Majewsky, Warsaw) have been found of various composition. Some which profess to have taken a prize at the Vienna Exhibition were composed of French brandy, containing common salt, and coloured with cochineal. The first was a spirituous solution of an ethereal oil with some oil of cloves, coloured rather reddish; No. 2 was a similar solution with some oil of peppermint and tincture of rhatany; and No. 3 was merely a diluted solution of No. 2. (Hager.)

AMERICAN UNIVERSAL BLOOD-PURIFYING HERB TEA (Dr Kuhr), for women’s diseases, hysteria, nervous debility, epilepsy, stomachic complaints, asthma, hæmorrhoids, gout, rheumatism, worms, and much besides. White horehound, marsh mallow, liquorice wood, and sassafras, of each, 10 parts; anise, coriander and fennel, of each, 5 parts; red poppy petals, 4 parts; lavender flowers, 2 parts; senna, peppermint, millefoil flowers, and valerian root, of each, 1 part. (Kuhr and Selle.)

AM′ETHYST (-thĭst). Syn. Purple rock-crystal; Améthyste, Fr.; Amethys′tus, L. A beautiful sub-species of quartz or rock crystal, of a violet-blue colour of varying intensity, in great request for cutting into seals, brooches, and other like articles of ornament. It was known and prized in the earliest ages of antiquity. Among the ancients, cups and vases were made out of this mineral; and it was an opinion of the Greeks and Persians, that an amethyst bound on the navel would counteract the effects of wine, and that wine drank out of an amethystine vessel would not intoxicate. See Gems.

Amethyst. In chromation, dyeing, &c., a rich variety of deep violet colour. Hence, AMETHYST′INE (ĭn), &c.

Amethyst, Orient′al. A rich violet-blue variety of transparent, crystallised corundum.

AM′IANTH (-e-ănth). Syn. Amianth′us, Amian′tus, L.; Amiante, Fr. The whiter and more delicate varieties of asbestos, particularly those which possess a satiny lustre.

AM′IDIN (-e-dĭn). [Eng., Fr.] Syn. Am′ydine; Amidi′na, L. A substance noticed by Saussure in starch-paste, when long kept. According to Caventou, it is formed at once by the action of boiling water on starch. It forms the interior substance of the starch-grains, and its properties are intermediate between those of starch and gum. It is, indeed, the soluble part of starch, of which a perfect solution can only be obtained by prolonged ebullition in a large quantity of water.

AMID′OGEN. NH₂. Literally, the generator of amides; in chemistry, the name given by Kane to an hypothetical body, composed of two atoms of hydrogen and one of nitrogen. It forms AMIDES by combining with other bodies.

Amidogen Ba′ses. In chemistry, ‘amines’ in which only one equiv. of hydrogen is replaced by an organic radical; and hence called PRIMARY MON′AMINES.

AMMONIA. NH₃. Syn. Ammonia gas, Ammoniacal gas, Anhydrous ammonia, Terhydride of nitrogen; Ammoniaque, Fr.; Ammoniak, Ger. At the present day the ammonia of commerce is chiefly prepared from the ammoniacal liquor of the gas-works and the manufactories of ivory black, animal charcoal, &c. Lant or stale urine is also an important source of ammonia. In these places a large quantity of crude ammoniacal liquor is produced; to which either sulphuric or hydrochloric acid is added, by which it is converted into a salt, which may be obtained nearly pure by evaporation, and one or more crystallisations, and, in the case of the hydrochlorate and carbonate, subsequent sublimation. Other sources and processes have been sought out and occasionally adopted for the preparation121 of the principal salts of ammonia (its sulphate, carbonate, and hydrochlorate); some of which have been patented, but few of them have got into general use, or have been carried out on the large scale. For many years the manufacture of ammonia and its compounds has incessantly engaged the attention of European chemists.

Many unsuccessful attempts have been made to directly convert the nitrogen of the atmosphere into ammonia. Of these we may mention one which consisted in passing a mixture of nitrogen, carbonic oxide and steam over red-hot hydrate of lime, whereby ammonia and carbonic acid are formed. A plan for the indirect application of atmospheric nitrogen in the preparation of ammonia was suggested by Margueritte, in which it was proposed that cyanide of barium should be prepared, and its nitrogen converted into ammonia by the aid of a current of superheated steam at 600° C. According to the description of this process in a patent, not, however, in practice, native carbonate of baryta is calcined with about 30% of coal-tar, for the purpose of rendering the mass porous as well as more readily converted into caustic baryta at a lower temperature. The carbonaceous mass is, after cooling, placed in a retort, and kept at a temperature of 300° C., while air and aqueous vapour are forced in, the result being the formation of ammonia in considerable quantity, and carbonate of baryta, which is again used.

Ammonia is evolved from ball soda while cooling; during the formation of cyanogen and cyanide of potassium in blast furnaces; and the formation of sal-ammoniac in the process of iron smelting.

Ammonia, in a state of combination, is found, in variable quantities, among the saline product of volcanoes, in sea and rain water, in bituminous coal, in urine, in guano, and in the atmosphere, especially that of large towns. The minute stellated crystals sometimes found on dirty windows in London, and other populous cities, consist of sulphate of ammonia. It is also found in clayey and peaty soils, and in minute quantity in good air and water. (Brande; Fownes; Letheby.) In the free state it exists in the juices of some plants, and in the living blood of animals, and it is freely developed during the decomposition of azotised vegetable substances, and during the putrefaction of animal matter.

Prep. A mixture of fresh hydrate of lime with an equal weight of sal ammoniac (both dry and in fine powder) is introduced into a glass flask or retort, the beak of which communicates with one end of a U-shaped tube filled with small fragments of recently burnt quick-lime, and from which extends another glass tube, about 18 inches long, having its further end bent up ready to be placed under a gas-jar, on the shelf of a mercurial pneumatic trough. (See engr.) The joints being all made air-tight by collars of india rubber, heat is applied by means of a spirit-lamp, and as soon as the air contained in the apparatus is expelled, the gas is collected for use. It cannot be dried by means of chloride of calcium. Powdered quick-lime may be substituted for the hydrate in the above process; in which case the evolved gas is anhydrous, but a much greater heat is then required for its liberation.

Comp. Ammonia is a compound of 3 volumes of hydrogen, and 1 vol. of nitrogen, condensed into two volumes; and by weight of 82·35 parts of nitrogen, 17·65 parts of hydrogen, or, in other words, of one atomic weight of nitrogen and three of hydrogen, having the formula NH₃.

Prop. Gaseous, colourless, invisible; highly pungent, acrid, irritating and alkaline; irrespirable, unless very largely diluted with air; extinguishes combustion; burns slowly in oxygen; sp. gr. 0·589; 100 cub. inches weigh 18·26 gr. Under a pressure of 6·5 atmospheres, at 50° Fahr., it forms a transparent, colourless liquid of the sp. gr. 0·731; at 60° Fahr. this liquid expanded into 1009 times its volume of ammoniacal gas; at -40° Fahr., and the ordinary atmospheric pressure, it forms a subtle colourless liquid, which at -103° Fahr. freezes into a white, translucent, crystalline substance. (Faraday.) It is highly basic; all its salts are either volatilised or decomposed at, or under, a red heat—those with a volatile acid sublime unchanged—those with a fixed acid lose their ammonia. It is decomposed into its elements by transmission through a red-hot tube; and when in contact with metallic oxides or spongy platinum, at the same temperature, the newly evolved hydrogen unites with the oxygen of the oxide or of the atmosphere, forming water. Water at 50° Fahr. absorbs 670 times its volume of this gas, and the solution has the sp. gr. 0·875. Its concentrated aqueous solution boils at 130°, and freezes at -40° Fahr.

Tests, &c. Ammonia is recognised by—1. Its pungent odour:—2. By turning vegetable blues green, and vegetable yellows brown; but which soon regain their previous colours, especially on the application of heat:—3. By producing dense white fumes when brought in contact with those of hydrochloric acid:—4. By the Nessler test (see Water, Quantitative and Qualitative Analysis of):—5. If a saturated solution of arsenious acid is mixed with a solution of nitrate of silver (strength 2%) a trace of ammonia causes the formation of try-argentic122 arsenite:—6. Böttger says a very delicate test for ammonia is afforded by an aqueous solution of carbolic acid. On adding to a liquid containing the smallest quantity of ammonia, or an ammoniacal salt, a few drops of this solution, and then a small quantity of a filtered solution of chloride of lime, the liquid becomes green, especially when warmed.

Phys. eff., &c. Inhaled, undiluted with air, it is an irritant poison, producing spasms of the glottis, convulsions, and death; even when diluted it acts as a powerful acrid, and local irritant; applied to the skin it causes vesication. The use of the pungent odour of common ‘smelling salts,’ in syncope, headache, &c., is well known. Largely diluted with air, it has been recently highly extolled in chronic hoarseness, asthma, &c.; and as an antidote to the fumes of bromine, chlorine, and hydrocyanic acid. (Smee.)

Ant., &c. The vapour of acetic acid or common vinegar, freely inhaled. It may be produced by sprinkling a little on a piece of hot iron, as a heated shovel. If bronchial inflammation follows, it must be treated by purgatives and a low diet; and, if severe, and the patient be plethoric or robust, by venesection or cupping.

Uses. Ammonia is employed in numerous processes in chemistry and the arts; but chiefly in the form of ‘liquor of ammonia,’ ‘spirits of hartshorn,’ &c., and in combination, under the form of salts. In its pure or gaseous state it possesses little practical interest.

Ammonia, Solution of. Syn. Solution of ammonia, Liquor ammoniæ, Ammonium hydrate, Ammonia, Eng.; Ammoniaque liquide, Dissolution d’ammoniaque, Esprit de sal ammoniac, Fr.; Atzender ammonium-liquor, Salmiak-geist, Ger.; Liquore di ammoniaco, Ital. Ammonia gas readily dissolves in water, one volume of water absorbing about 670 volumes of ammonia, much heat being liberated, and the solution increases greatly in volume.

This solution is regarded in two very different lights; firstly and most generally as simply a solution of gaseous ammonia, a view rendered most probable by its general physical and by many chemical reactions; by a few, however, it is looked upon as a solution of ammonium hydrate.

Prepared by distilling, in a tubular retort, equal parts of sal ammoniac, hydrated lime, or slaked lime and water, and passing the gas evolved through a set of Wolff’s bottles partially filled with water, as in the figure above.

Commercially this article is prepared on the large scale, from a mixture of about equal parts of fresh-slaked lime and sal-ammoniac or sulphate of ammonia, which is heated in an iron cylinder or retort connected with a set of ‘refrigerators,’ the latter consisting of a row123 of stoneware bottles with double necks, containing water, and kept very cold. The general arrangement of the apparatus used in this manufacture is exhibited above, and with the accompanying references, will be easily understood. The ‘condensers,’ when in use, are surrounded with cloths (not shown in the engr.) kept wet with very cold water, whilst constant current of cold air is commonly made to pass over them. The pipe (D) leading from the retort is also several feet long, and is advantageously passed through a wooden screen in order that the radiated heat of the retort and brickwork of the furnace may be intercepted as much as possible.

Two different methods of proceeding are adopted in this process. In the one the dry pulverulent ingredients are mixed together, and the resulting gas distilled over into the water placed in the receivers. In the other the lime is made into a ‘pap’ with water, and the ammonia-salt, in coarse powder, being added, the whole is rapidly blended together, before closing the retort, and applying heat. In either case a proportionate quantity of water is put into the condensers, and the operation is nearly similar; but the latter method requires the least heat, and so far as the receivers and refrigerators are concerned, is, perhaps, the one most easily managed. It is that which is always, and necessarily followed, when sulphate of ammonia is employed.

Prop., Uses, &c. Highly pungent, caustic, and alkaline; lighter than water, and presenting in a liquid form most of the characteristics of pure ammonia. When strongest has a sp. gr. of ·875, and contains about 39 per cent. of ammonia, but the usual strong ammonia of commerce has a sp. gr. of but ·88. The liquor ammonia fortior, B. P., has a sp. gr. of about ·893, and contains 32·5 per cent. of ammonia, while the liquor ammoniæ B. P. has a sp. gr. of about ·940, and contains about 10 per cent. of ammonia. As a medicine it is antacid, diaphoretic, rubefacient, stimulant, and counter-irritant; and is used in various affections in which these remedies are indicated. As a vesicant it is superior to cantharides, and as a caustic it is used with advantage in the bites of rabid animals, especially those of serpents and insects. Its vapour is a common nasal stimulant in faintings, epilepsy, &c. In its concentrated form it is a corrosive poison.—Dose, 5 to 25 drops, in cold water, or milk and water. It enters into the composition of several valuable external remedies, and is in constant employment in the chemical laboratory, both as a reagent and for the preparation of other compounds.

Ant., &c. When the fumes have been inhaled, the patient should be exposed to a current of fresh air; and when the liquid has been swallowed, vinegar or lemon-juice mixed with water may be administered; followed by an emetic, or, on its failure, by the stomach-pump.

Estim. The quantity of gaseous ammonia in pure water of ammonia is easily determined from the specific gravity of the liquid, or from its saturating power. When impure or mixed with other substances, a given weight of the sample is placed in a small retort, the end of which is made to dip into a vessel containing dilute hydrochloric acid. A strong solution of caustic potassa is then poured into the retort, and heat applied by means of a small spirit lamp. When all the ammonia is distilled over, the acid solution is evaporated to dryness, by the heat of a water bath, and the residuum (chloride of ammonium) weighed. Each grain of the chloride thus found represents ·31804 gr. of pure ammonia; 53·5 parts of the former being equivalent to 17 of the latter. If the article for examination be a solid substance (as a salt), it may be dissolved in water, or in dilute acid, before being put into the retort.

In accurate experiments in the laboratory, ammonia is usually WEIGHED either as chloride of ammonium (see above), or as ammonio-bichloride of platinum (NH₄Cl, PtCl₂); every gr. of the latter representing ·07614 gr. of pure ammonia. Sometimes, though rarely, the quantity of ammonia is determined from the volume of nitrogen eliminated from it, of which 14 gr. represent 17 gr. of ammonia.

Concluding remarks, Patents, &c. Whatever form or process may be adopted for the preparation of liquid ammonia, it is absolutely necessary to keep the receivers as cool as possible, by means of snow, ice, or a current of very cold water, for the purpose of promoting the absorption of the gas, and to prevent its loss. On the small scale, the glass receivers or bottles may be most conveniently surrounded with ice, or a freezing mixture, and two, or more of them, should be furnished with safety-tubes, to prevent accidents. On the large scale, a capacious oblong retort, usually of iron (but sometimes, though seldom, of lead), with a large opening or tubulature conveniently situated for inserting the ‘charges,’ and withdrawing the residuum of the distillation, is employed. The tubulature, or opening, is closed by means of a large and accurately ground iron stopper, or with a door secured by screws, as the case might be. The stopper is well greased before insertion, and is removed by means of a powerful lever. Should it become so firmly fixed that it cannot be displaced in the usual manner, a cloth moistened with cold water, and carefully wrapped round it, without touching the neck of the retort, will generally cause it to contract sufficiently to enable the operator to remove it with facility. Sometimes a large iron kettle, with a moveable and accurately fitting lid secured in its place like that of a ‘Papin’s digester,’ and having a large and long tubulature in its centre, is employed instead of a retort, over which it has the advantage of exposing a larger opening for the removal of the residuum of the process. In either case the distillatory124 vessel is imbedded in sand supported by fire-brick, and is not exposed directly to the heat of the furnace. Before commencing the distillation the joints are all well luted, to avoid leakage. An excellent plan is to pass the gas, as it leaves the retort, through a silver or pewter ‘worm’ or ‘refrigerator’ set in a tub supplied with a stream of very cold water; by which it will be sufficiently cooled before it reaches the ‘receivers’ to obviate the necessity of any further attention to them than keeping the cloths wrapped round them constantly moistened with cold water. The lower end of the ‘worm’ should be connected, by means of a balloon-shaped ‘adopter,’ with the ‘still,’ and the upper end with the first ‘receiver,’ the use of the balloon being to intercept any volatilised ammonia-salt that might be accidentally driven over by the heat being too high, or too suddenly raised.

The heat should be gradually applied, and very gradually raised, to prevent any of the sal ammoniac or sulphate being volatilised undecomposed; and even towards the end of the process it should not even approach redness.

The lime is best ‘slaked’ and ‘papped’ with about 4 parts of water; as a lower heat is then required to expel the gas, and it passes over more easily and fully than when less water is employed. This is absolutely necessary when the sulphate is the ammonia-salt used; as otherwise the residuum of ‘sulphate of lime’ would become so hard that it could not be easily removed from the retort.

The gas being wholly expelled from the retort, or other distillatory vessel, it is disconnected from the receivers, and (when sal ammoniac has been employed) the heat is raised sufficiently high to fuse the residual chloride of calcium, which is then at once baled or poured out. Glass retorts often suffer fracture at this point; but if they escape now, it generally happens that they are broken when heat is applied for a second operation. Hence, according to Prof. Muspratt, it is rare to find a retort, even when carefully handled, that will stand two operations.

When crude sulphate of ammonia is employed it is advisable to have only a little water in the first receiver, which is placed there merely to purify the gas which passes through it, and to retain any traces of volatile empyreumatic or oily matter which may be carried over with it.

Pure solution of ammonia is most easily obtained from ‘sal ammoniac,’ but crystallised sulphate of ammonia, often crude, is more commonly employed, on account of its lower price.

The preparation of pure solution of ammonia admits of no other improvements than such as merely affect the form of the apparatus employed to produce it; and hence, unlike the ammonia-salts of commerce, has been little meddled with by inventors and patentees. Among the plans having for their object the production of an ammoniacal solution, more or less concentrated, fitted for many of the purposes of the arts, and for the preparation of salts, but not for chemical and medical use, besides those of Reece, Spence, Crane and Jullien, &c., already noticed, may be mentioned—

1. That of Watson (Patent dated 1838) in which gas-liquor mixed with a proper quantity of fresh-slaked lime is distilled from a spacious retort or still into a receiver containing cold water, until much steam passes over with the gas, when the strong alkaline liquor forming the distillate, and called the first portion, is drawn off. The distillation is then continued, when a weaker and impurer solution is obtained, called the second portion. The first portion is then reintroduced into a retort or still with a small quantity of fresh lime, and the distillation repeated. The product the patentee calls the first portion of the second distillation. The latter is a strong ammoniacal liquor sufficient for all the purposes of scouring, cleaning, conversion into commercial ammonia-salts, &c. It may be further purified by a third distillation; the second portion of each operation being transferred again to the still with the next fresh charge of gas-liquor.

2. A modification of Coffey’s still,[43] patented by Mr W. E. Newton (1841), under the name of the ‘AMMONIA STILL,’ is now extensively and successfully employed in this manufacture. By its use ammonia may be obtained from ‘gas-liquor,’ ‘bone-spirit,’ or any other ammoniacal liquor or solution, and even from solutions of the salts of ammonia, of almost any density, and of considerable purity; and this by a process which is continuous and inexpensive. The body of the apparatus is formed of wood, the chambers are lined with lead, and the diaphragms are of perforated sheet iron. The management of the apparatus varies with the form in which it is desired to obtain the product. When the ammonia is required to leave the upper chamber of the rectifier in the form of gas, either pure or impure, the steam which ascends, and the current of ‘ammoniacal liquor’ which descends, are regulated in such relative proportions that the latter remains at or near the atmospheric temperature during its passage through some of the upper chambers, becoming successively hotter as it descends, until at length it enters into ebullition; in which state it passes through the lower chambers, either to make its escape, or to enter a cistern provided to receive it. If, on the contrary, the ammonia is required to leave the upper chamber in combination with the vapour of water, the supply of steam entering below must be in such proportion to that of the ammoniacal125 liquor supplied from above, that the latter may be at or near the boiling temperature in the upper part of the apparatus. Crude liquor and ammonia-salts, before being thus submitted to distillation, are, of course, first treated with a proper quantity of quick-lime—in the one case to remove most of the impurities, and in the other to set the ammonia free by seizing on its acid.[44]

The water or solution contained in the first bottle or the first receiver is found to be the strongest, provided it has been kept well cooled; and that in the others, of progressively decreasing strength. By mixing the contents of one bottle with another a solution of almost any strength may be made. It is also easy to prepare liquor of ammonia of any required strength, or to ascertain the strength of that in the receivers, by observing the expansion of the liquid. Water, when fully saturated with ammonia, expands from 3 volumes to 5 vols.; and in less, but corresponding proportion, according to the quantity absorbed. All that is necessary in practice is, that each receiver be furnished with a gauge-pipe by which the degree of expansion may be noted. On the small scale, graduated glass receivers may be used.

3. Mallet’s Apparatus. This, which is employed in many of the large gas works, is shown in vertical section in the accompanying woodcut. Steam is forced into large receptacles, which are filled with gas water, by which means the carbonate of ammonia is volatilised. When lime, as is sometimes the case, is added, ammonia gas is evolved, and this being conveyed into weak sulphuric acid, sulphate of ammonia is the result.

The apparatus consists of two cylindrical boiler-plate vessels, A and B. A is heated directly by the fire, and has a leaden tube, c, which dips into the liquid contained in B, this vessel being so placed as to catch the waste heat from the fire. b and e are man-holes; a and a′ are stirrers. By means of the tube d the fluid from B can be run off into A. Gas-water is poured into both vessels, and lime added; ammonia is liberated, whilst carbonate of lime and sulphide of calcium are formed, and these latter remain in the vessels after the volatilisation of the ammonia. The vessel D is also filled with ammoniacal water, and when the operation is in action this water, already warmed, is run by the aid of the tube h from D into B. E is a gas-water tank, from which D is filled by means of g. The ammonia set free in A is, with the steam, conveyed by the pipe c into B, thence through c′ into the wash-vessel C, and thence again through c′′ into the first condenser, D. The partially condensed vapour now passes into the condensing vessel F, the worm of which is surrounded by cold water. The dilute ammonia is collected in G, and forced by means of the pump (R) into C, from whence it is occasionally removed by means of a syphon into either A or B. The non-condensed ammoniacal gas is carried from G through a series of Wolfe’s bottles, the first bottle (H) containing olive oil, with the object of retaining any hydrocarbons that may be present in the gas; the bottle J contains caustic soda-ley, in order to purify the ammonia and retain impurities; the bottle K is half filled with distilled water. The ammoniacal gas having passed through K, is conveyed to the large wooden tank (lined with lead) L, filled with diluted sulphuric acid, if it is intended to prepare sulphate of ammonia, or with water, if solution of ammonia be required. The vessel L is placed in a tank of water; i is a small pipe for introducing acid, while the tube leading to M serves to carry off any unabsorbed ammonia, M being likewise filled with acid.

4. By means of Rose’s apparatus, the ammoniacal gas-liquor mixed with one third of slaked lime is heated in a boiler to a temperature of from 96° to 100°, the ammoniacal gas evolved being passed into hydrochloric acid, and thence through charcoal into vessels containing from 120 to 150 litres of water, which is converted into liquid ammonia of a sp. gr. 0·920.

5. In Lunge’s apparatus the gas-water is heated in a boiler, and the liberated ammoniacal gas passed into sulphuric acid.

Solution of ammonia is now seldom made by the druggist, or on the small scale, the large manufacturing chemists supplying it at a very low rate, and of very superior quality. In the shops it is kept of two or three strengths.

The estimation of the strength of ammonia solutions in commerce is known as ammonimetry, and depends upon their specific gravities. The per-centage richness of solutions of ammonia, or of its carbonates, may be most accurately determined, by ALKALIMETRY. For all the ordinary purposes of commerce, and of the laboratory, the strength of pure solutions of ammonia may, however, be inferred, with sufficient correctness, from their density; and to this the term AMMONIOMETRY is usually restricted.

The specific gravity of the sample being found either by the hydrometer [45] or specific gravity bottle, in the usual manner, its per-centage strength may be seen by inspection of the following Table and the Table on p. 127.

Sp. Gr. by experiment.	Water of Ammonia of 900, per cent.	Pure Ammonia, per cent.	Water, per cent.
·9000	100	26·500	73·500
·9045	95	25·175	74·825
·9090	90	23·850	76·150
·9133	85	22·525	77·475
·9177	80	21·200	78·800
·9227	75	19·875	80·125
·9275	70	18·550	81·450
·9320	65	17·225	82·775
·9363	60	15·900	84·100
·9410	55	14·575	85·425
·9455	50	13·250	86·750
·9510	45	11·925	88·075
·9564	40	10·600	89·400
·9614	35	9·275	90·725
·9662	30	7·950	92·050
·9716	25	6·625	93·375
·9768	20	5·300	94·700
·9828	15	3·975	96·025
·9887	10	2·650	97·350
·9945	5	1·325	98·675

⁂ Strengths corresponding to sp. gr. which are not in the above Tables may be found by the ‘method of differences’ explained under Alcoholometry.

⁂ The sp. gr. of any sample of liquid ammonia, expressed in three integers, deducted from ·998, and the remainder divided by 4, gives a number which represents the per-centage strength, nearly. (Ure.) This rule may be sometimes conveniently employed for rough calculations, in the absence of Tables.

Ammonia, Carbonates of. (B. P.) Syn. Ammoniæ carbonas. See Ammonium, Sesquicarbonate of.127

Sp. Gr. of the Liquid Ammonia.	Pure Ammonia per cent., by Weight.	Sp. Gr. of the Liquid Ammonia.	Pure Ammonia per cent. by weight.	Sp. Gr. of the Liquid Ammonia.	Pure Ammonia per cent., by weight.
·87500	34·694	·91750	21·837	·96000	10·119
·87625	34·298	·91875	21·477	·96125	9·790
·87750	33·903	·92000	21·118	·96250	9·462
·87875	33·509	·92125	20·760	·96375	9·135
·88000	33·117	·92250	20·403	·96500	8·808
·88125	32·725	·92375	20·046	·96625	8·483
·88250	32·335	·92500	19·691	·96750	8·158
·88375	31·946	·92625	19·337	·96875	7·834
·88500	31·558	·92750	18·983	·97000	7·511
·88625	31·172	·92875	18·631	·97125	7·189
·88750	30·785	·93000	18·280	·97250	6·867
·88875	30·400	·93125	17·929	·97375	6·547
·89000	30·016	·93250	17·579	·97500	6·227
·89125	29·633	·93375	17·231	·97625	5·908
·89250	29·252	·93500	16·883	·97750	5·590
·89375	28·871	·93625	16·536	·97875	5·273
·89500	28·492	·93750	16·190	·98000	4·956
·89625	28·133	·93875	15·846	·98125	4·641
·89750	27·736	·94000	15·502	·98250	4·326
·89875	27·359	·94125	15·158	·98375	4·011
·90000	26·984	·94250	14·816	·98500	3·698
·90125	26·610	·94375	14·475	·98625	3·386
·90250	26·237	·94500	14·135	·98750	3·074
·90375	25·865	·94625	13·795	·98875	2·763
·90500	25·493	·94750	13·456	·99000	2·453
·90625	25·123	·94875	13·119	·99125	2·144
·90750	24·754	·95000	12·782	·99250	1·835
·90875	24·386	·95125	12·446	·99375	1·527
·91000	24·019	·95250	12·111	·99500	1·220
·91125	23·653	·95375	11·777	·99625	·914
·91250	23·288	·95500	11·444	·99760	·609
·91375	22·924	·95625	11·111	·99875	·304
·91500	22·561	·95750	10·780	1·00000	0 or Water.
·91625	22·198	·95875	10·449

⁂ The specific gravity of mixtures of pure solution of ammonia and pure water is precisely the mean of the specific gravities of their constituents. (Davy; Dalton; Christison.) In all solutions of ammonia, a quantity of anhydrous ammonia, weighing 212¹⁄₂ gr., displaces exactly 300 gr. of water, and reduces the sp. gr. of the liquid to the extent of ·00125. (Griffin.) The strongest solution of ammonia which it is possible to prepare at 62° Fahr. has the sp. gr. ·87500, and contains 34·694% of pure ammonia, by weight, or 21,251 gr. per gallon. (Griffin.)[46]

AMMONIUM. The name given to a group of atoms, which play the part of a compound basic, radical, or metallic element. This substance, whose formula is NH₄ or (NH₄)₂, has never been isolated, although capable of forming most stable salts with the various acid radicals. Several attempts have been made, however, to obtain this compound radical, or group of elements, in a free state, and with more or less success, but on account of its great instability it invariably decomposes when set free into ammonia and hydrogen.

Ammonium salts are some of the most important chemical agents, and are usually recognised as follows, ammonia solution, however, usually acting in exactly the same manner as a solution of ammonium hydrate:—By imparting a deep blue tint to solutions of salts of copper. By exhalation of ammoniacal gas (recognised by its odour), when triturated or mixed and heated with caustic potassa, soda, or lime. Added to a solution of bichloride of platinum, they produce a heavy yellow, crystalline precipitate, consisting of minute octahedrons128 easily discernible under the microscope. With protonitrate of mercury, a black precipitate. With bichloride of mercury, a heavy, white precipitate. With a concentrated solution of tartaric acid, a crystalline, white precipitate, nearly similar to that given with salts of potassa. They are nearly all soluble in water, volatile, and crystallisable.

Except the carbonate, they are almost invariably estimated by conversion into ammonia, and estimation by volumetric analyses, as in alkalimetry. In the laboratory, however, for exact purposes, they are converted into the double chloride of ammonium and platinum.

Ammonium, Acetate of. NH₄C₂H₃O₂. Syn. Ammo′′niæ ace′tas, L.; Acetate d’ammoniaque, Fr.; Essigsäures ammoniak, Ger. Prep. 1. Take of acetate of lime or of potassa and sal ammoniac, equal parts; mix and distil at a gentle heat. The oily liquid (BINACETATE OF AMMONIUM, HNH₄(C₂H₃O₂)₂), in the receiver forms a radiated crystalline mass on cooling. Dry gaseous ammonia passed into this salt, melted by a gentle heat, transforms it into the solid and inodorous neutral acetate, NH₄C₂H₃O₂.

2. Strong acetic acid is saturated with ammonia or carbonate of ammonium, and the solution evaporated over sulphuric acid in vacuo; the resulting crystals, after being carefully drained, are dried by pressure between bibulous paper.

Prop., &c. Long, slender crystals, or a crystalline mass, freely soluble in both alcohol and water, and deliquescent in the air; taste sharp and cooling, and somewhat sweetish. Its solutions cannot be evaporated without loss of the ammonia; even the salt passes off in large quantities with the vapour of water. Its aqueous solution becomes alkaline on keeping, from decomposition of the acid. Distilled with anhydrous phosphoric acid, it is converted into ACETONITRILE. An aqueous solution of this salt was introduced into the Materia Medica by Boerhaave, and has since been extensively used as a diaphoretic and febrifuge, under the popular name of MINDERERUS SPIRIT, after Minderer or Mindererus, who extensively employed it and extolled its virtues. When pure, both the salt and its solutions are neutral to test-paper, and are wholly volatilised by heat. See Solutions.

Ammonium, Arseniate of. (NH₄)₃AsO₄. Syn. Ammoniæ arse′nias, L. Prep. 1. (Neutral.) Saturate a warm concentrated solution of arsenic acid with carbonate of ammonium in slight excess; evaporate by a gentle heat, that crystals may form on cooling.

2. Ammonium, Binarseniate of. H(NH₄)₂AsO₄. As above, but adding an additional equiv. of the acid, as soon as any excess of ammonia has been expelled by the heat employed to evaporate the solution.—Dose (of either). 1-24th to 1-12th gr.; in phthisis, certain skin diseases, &c. See Solutions (and below).

Ammonium, Arsenite of. NH₄AsO₂. Syn. Ammoniæ ar′senis, L. Prep. From a hot concentrated solution of arsenious acid, and sesquicarbonate of ammonium, as the last.—Used (chiefly) to make arsenite of iron. The properties and physiological effects of the above arsenical preparations are for the most part similar to those of arseniate and arsenate of potassa. They are all poisonous.

Ammonium, Benzoate of. Prep. 1. Dissolve benzoic acid in ammonia solution to saturation, then further add ammonia in slight excess, and crystallise by refrigeration, or in vacuo.

2. (Liquid; Solu′tio ammoniæ benzoa′tis, L.) As the last, but without evaporating the solution.

Prop., &c. Very soluble and very difficult to crystallise. If the solution is boiled for a short time and then abandoned to spontaneous evaporation, crystals of ACID BENZOATE OF AMMONIUM are deposited. It is used chiefly as a chemical test; but has been recently recommended in chronic bronchitis, old coughs, &c.; and to check the formation of chalk-stones and urinary calculi.—Dose, 10 to 15 gr.; (of the solution) 15 drops to 1 fl. dr., or more. See Benzoic Acid.

Ammonium, Bromide of. NH₄Br. Syn. Ammo′′nii bromi′dum, A. bro′mis, L.; Hydrobromate d’ammoniaque, Bromure d’ammonium, Fr. A salt which is obtained from hydrobromic acid, bromide of iron, &c., by similar processes to those adopted for the iodide. The following process for the preparation of bromide of ammonium is from the formula for the new medicaments adopted by the Paris Pharmaceutical Society: “Add bromine very slowly to a solution of ammonia, with continual stirring, until the liquid remains faintly and persistently coloured by a slight excess of bromine.” It forms white prismatic crystals; and, in its general properties, resembles bromide of potassium. It is volatile, and easily decomposed.

Used as a nervine in hysterics; especially useful for sleeplessness where there is no organic disease; given in epilepsy when bromide of potassium fails.—Dose, 2 to 20 grains.

Ammonium, Carbonate of. Syn. Neutral carbonate of ammonium. Equal parts of dry sal ammoniac and sodium carbonate are heated to form the neutral ammonium carbonate of commerce, which sublimes. Solid crystalline substance, with a strong ammoniacal odour, volatile and soluble.

Uses, &c. In the solid form it is not now used in medicine; but it is indirectly employed in several liquid preparations in which the sesquicarbonate is ordered. It is superior to any other preparation of ammonia for filling smelling bottles; as it is not only more pungent, but does not lose its pungency by keeping. It volatilises more quickly than the sesquicarbonate,129 and the residuum, unlike that of the latter salt, continues as odorous as ever. It is the basis of several of the most popular and esteemed advertised smelling salts of the shops. Spirit of hartshorn is an impure solution of this salt, originally obtained by distilling hartshorn or bones.

Ammonium, Sesquicarbonate of. Probably 2NH₄HCO₃ + NH₄NH₂CO₃, i. e. a mixture or compound of bicarbonate of ammonium and carbamate of ammonium. Syn. (Carbonate of ammonia, Ammoniæ carbonas. B. P.). Carbonate d’ammoniaque, Fr.; Kohlensaures ammoniak, Ger. It is prepared on a very large scale commercially as follows:—Sal ammoniac or sulphate of ammonia, and chalk, equal parts, both dry and in powder, are mixed as before, and sublimed from a series of iron retorts or iron pots, into a well-cooled and capacious receiver lined with lead or earthenware; or, more generally, into such a receiver connected, by iron or lead pipes, with a second and similar one containing a stratum of water, to absorb the free ammonia evolved during the process.

The so-called “Volcanic Ammonia” is evolved during the manufacture of borax, from carbonate of soda and boracic acid. It is largely used in pharmacy.

Prop. The carbonate of ammonia, of commerce, usually occurs in the form of white, fibrous, translucent, or semi-translucent cakes, generally about two inches thick. It is less volatile and pungent than the neutral carbonate; soluble in 4 parts of water at 55° Fahr., 3·3 parts at 62°, 2·5 parts at 96°, and 2 parts at 120°; boiling water and alcohol decompose it, with the evolution of carbonic acid gas and ammonia; by age or exposure to air, the surface assumes an opaque white colour, from its carbonate flying off, and the remaining bicarbonate being less volatile. Unlike the carbonate, it can neither be resublimed nor digested or distilled with either alcohol or water, without suffering decomposition. Sp. gr. 0·966.

The exact composition of this salt varies, according to its method of preparation.

Uses, &c. It is commonly employed by bakers to give lightness to their fancy goods, and to make extemporaneous bread and pastry; by the chemist and pharmaceutist, for the preparation of other salts of ammonia, and in analysis, &c. In medicine it is used as a stimulant, antispasmodic, antacid, and diaphoretic, in acidity of the stomach, dyspeptic affections, gout, scrofula, hysteria, lowness of spirits, epilepsy, &c.; and in the convulsions attending dentition. It has been recently recommended, by Dr Barlow, in diabetes. It is also employed to make effervescing draughts; and externally as a counter-irritant and stimulant. Its use as a nasal stimulant in headaches, fainting, &c., is well known. In large doses it is emetic; in excessive doses poisonous. Its long-continued use, in quantity, is often productive of very serious consequences—slow fever, debility, emaciation, scurvy, loss of teeth, hæmorrhage, general cachexy, and even death. The antidote and restorative treatment are, the free use of lemon-juice, wine or malt-liquors, new milk, and antiscorbutic vegetables, with a generous diet, of which the red meats form a large proportion.—Dose. As a stimulant or diaphoretic, 5 to 15 gr., dissolved in cold water; as an emetic, 20 to 30 gr., in tepid water, repeated if necessary; as an effervescing saline draught, 15 to 30 gr. A few grains (8 or 10) dissolved in a tumbler of cold water is an excellent ‘refresher’ in lowness of spirits, or after fatigue; and is highly esteemed by drunkards; being, in each case, preferable to ‘spirit of sal volatile,’—Doses for Animals. Horse: 1 to 2 drachms. Cattle: 2 to 4 drachms. Sheep: 20 grains to 1 drachm. Pig: 20 grains to 1 drachm. Dog: 3 to 10 grains; in bolus, pill, or cold gruel.

Concluding remarks, Patents, &c. In extension of the above it may be added that, on the large scale, the distillation is usually carried on in cast-iron retorts, similar in size, shape, and character to those employed in the manufacture of coal-gas, and of which five, or more, are commonly set horizontally in the same furnace. (See engr.) Each retort has its mouth (a), through which the ‘charge’ is introduced, closed with a movable door, which is securely fastened in its place, in the manner shown in the engr.; and is furnished, at the upper part of its further end, with an iron pipe (c), to carry off the evolved vapours to the condenser or receiver. The latter consists of two large square wooden chambers (B, C), lined with lead, and either fitted with movable covers, secured by water-joints, or with doors in the side, to permit of the easy removal of the sublimed salt. The first receiver communicates with the second by means of a large lead tube (d) near its centre, and by another tube (d′), somewhat smaller, and nearer the bottom, but above the surface of the stratum of water in the second receiver, before alluded to. These chambers have also a lead pipe (e, e), stopped during the process with a plug or cock of lead, to allow of the liquid product of the distillation, &c., to be drawn off, or run into another receiver or cistern, at will. Both chambers are placed on strong wooden supports, or scaffolding, to bring them on a level with the retorts. When the impure sulphate or other ammonia-salt is used in the manufacture of the sesquicarbonate (which is generally the case), the resulting salt being impure and discoloured, is resublimed in iron pots (f, f, f), furnished with movable leaden heads, which are kept cool by a current of air passing over them; a little water being introduced into the subliming pots to render the product translucent. The heat is applied either by means of a flue passing from the retort-furnace (A, b), or by a water bath heated in the same manner; the latter being the preferable method, as the temperature130 should not be greater than about 200° Fahr., and need not exceed 150° to 155°. These pots are arranged in sets, as shown at D in the engraving.

The charge of a retort usually consists of about 70 to 72 lbs. of sulphate of ammonia or 57 to 58 lbs. of the hydrochlorate to 1 cwt. of chalk; or in these proportions. The product is about 40 lbs. of the crude salt, which, by careful resublimation, yields about 39 lbs. of marketable carbonate of ammonia.

Carbonate of ammonia, like the chloride and sulphate, is now scarcely ever prepared on the small scale, that of commerce being not only cheaper, but sufficiently pure for all the purposes of medicine and the arts.

Ammonium, Bicarbonate of. HNH₄CO₃. Prep. By digesting cold water on sesquicarbonate of ammonia in considerable excess, until the whole of the pungent neutral carbonate is dissolved out. If the salt is reduced to powder the operation is facilitated.

To powdered sesquicarbonate of ammonia add boiling water just sufficient to dissolve it, and immediately close the vessel; crystals form as the liquid cools, containing 2¹⁄₂ equiv. of water.

Prop., &c. For the most part similar to the sesquicarbonate, except in having a taste and smell which is only faintly ammoniacal, and hence more palatable. Crystallises in oblique prisms, which, as usually obtained, contain about 23% of water. It requires 8 parts of cold water to dissolve it. It is distinguished from the previous carbonates by the almost entire absence of ammoniacal odour, and by its solution giving no immediate precipitate with chloride of barium, but by standing, or on the addition of a little liquor of ammonia, a white earthy precipitate, accompanied with the evolution of carbonic acid gas. A saturated solution of this salt, evaporated by a very gentle heat, or refrigerated, gives small prismatic crystals having neither smell nor taste.

Uses, &c. Similar to those of the other carbonates.—Dose, 6 or 7 to 20 or 25 gr.

Ammonium, Chloride of. NH₄Cl. Syn. Muriate of ammonia, Sal ammoniac, Hydrochlorate of ammonia; Chlorohydrate d’ammoniaque, Sel ammoniac, &c., Fr.; Salmiak, Ger. A substance which, as already noticed, appears to have been originally obtained, by sublimation, from the soot of camels’ dung, in Egypt. In this country, at the present day, it is manufactured chiefly from the crude ammoniacal liquors obtained as secondary products in the manufacture of coal-gas and animal charcoal.

Prep. 1. From GAS-LIQUOR:—The crude ammoniacal liquor of the gas-works is, either at once, or after distillation,[48] neutralised with hydrochloric or sulphuric acid, the choice being given to the one which is the cheaper and more accessible at the place where the works are situated. When hydrochloric acid is employed, the SATURATION is usually effected by allowing the acid to flow from a large wooden vessel or tank lined with lead or gutta percha into a large underground reservoir or tank containing the ammoniacal liquor, and having an exit-tube passing into the chimney or shaft of the steam-engine, to carry off the sulphuretted hydrogen and other offensive gases liberated during the mixture. Sometimes the gas-liquor is accumulated in enormous covered wooden tuns, capable of holding from 10,000 to 20,000 gallons, or more; and the acid is added by raising the gutta-percha carboys containing it by means of cranes, and then thoroughly mixing it with the liquor by means of powerful ‘agitators,’ whilst the offensive fumes are either passed off as before, or made to traverse the fire of the steam-engine before entering the chimney-shaft. The quantity of acid employed to effect saturation must, of course, depend on the ammoniacal strength of the gas-liquor operated on. The usual proportions are 1¹⁄₂ to 2 lbs. of the former, to each gal. of the latter; but in all cases sufficient should be added to impart a very faint acid reaction to the mixture. This last having been effected, the saline131 solution, now containing hydrochlorate of ammonia, is, after repose, ready to be pumped or run off into the evaporators.

The EVAPORATION of the crude saline solution is usually carried on in large square or rectangular cast-iron vats, of very moderate depth, and capable of holding from 1000 to 1500 gallons, or more. These are encased in brickwork, and are heated by a furnace, of which the flues pass in a sinuous course beneath the lining of brickwork on which the vats or pans rest. During the concentration of the liquid, the tar, &c., which separates and floats on the surface, and which thus seriously impedes evaporation, is, from time to time, removed by skimming. As soon as the sp. gr. reaches 1·25, any excess of acid in the solution is exactly neutralised with a little fresh ammoniacal liquor; by which any waste of acid is prevented, at the same time that any ferric salt present, and which would contaminate the ultimate product, is precipitated as sesquioxide. After settling for a short time, the hot liquor is ready to be transferred to the crystallisers.

The vessels employed in the CRYSTALLISATION are pans or tubs, usually circular and about 7 or 8 feet wide, by 2¹⁄₂ to 3 feet deep; and are generally set on the ground, or are embedded either partially or wholly in it. The saline liquor being pumped or run into them at a little below the boiling temperature, crystallises as it cools; the only interference being occasional stirring or agitation, to prevent the formation of large crystals, which would be inconvenient in the subsequent part of the process. The time occupied in the crystallisation varies, according to the size of the ‘crystallisers,’ and the weather, from 3 or 4 to 8 or even 10 days. The ‘mother-liquor’ of the ‘crystallisers’ is pumped back into the evaporating pans for further concentration. The crude blackish salt (hydrochlorate) thus obtained is contaminated with tarry and oleaginous matter, free acid, water, &c.; from part of which it is freed by exposing it in a layer about 4 inches deep, on a cast-iron plate gently heated by a zigzag flue of a small furnace, until all the water is expelled; care being taken that the heat never rises high enough to volatilise the salt. This operation is generally performed under a dome, or the expanded throat of a large chimney. The salt will now have become of a greyish-white colour, and is ready for the next operation.

The crude dried salt of the last process is finally purified by sublimation. For this purpose cast-iron-pots lined with clay, and heated from below and by flues round their sides, are employed. (See engr.) The crude grey salt is beaten down into these pots until they are about 2-3rds filled, when the heads or capitols are fitted on, and heat applied. The latter are very heavy, being usually made of lead (sometimes of iron), and have the form of a dome, or a hemispherical cup, with a small tube or hole at the apex, in which a plug is loosely placed, to permit the escape of steam. These domes or heads are so made as to fit closely and firmly on the flat rim or flange of the ‘sublimers,’ and are retained in their places, during use, both by their weight, and by 2 or 3 clamps provided for the purpose. They are also furnished with 3 rings, set at equal distances, to allow of their being lifted off, or moved, by means of a pulley and chains. The due application and regulation of the heat is here of the utmost importance. If the temperature employed be too high, the sublimed salt will be contaminated with empyreumatic matter, while some of it will be carried beyond the dome and lost; and if it be extreme, the head may be altogether blown off, and the contents of the pan scattered about the building; whilst on the other hand, if the heat employed be too low, the resulting cake of sal ammonia will be soft, spongy, and either grey or yellowish. The proper temperature is said to be known by two or three drops of water readily boiling, and being dissipated in vapour, when placed on the head or cover of the sublimer; but it should not ‘spit’ or ‘dance about,’ or be raised by the heat out of contact with the metal. The usual practice is to keep the fires “briskly up until the sublimers and their surroundings attain a sufficient degree of heat; they are then slackened, and maintained at a mean temperature.” (Muspratt.) The sublimation occupies from 5 to 9 days; but it is customary to raise the heads once, or even twice a week, to ascertain the progress made; the fires having been purposely neglected or checked for some hours previously. The process is finally stopped132 before the whole of the crude salt in the pots is volatilised; since the heat required for that purpose would lead to the decomposition of the carbonaceous impurities, and cause them to emit volatile hydrocarbons, which would materially lessen the purity and beauty of the product. The unsublimed portion in the pots forms a conical mass, which is technically called the ‘yolk.’ This is shown in the second engr. (see below), in which the latest improvements in the form of the subliming apparatus are also exhibited.

The sublimation having been carried to a sufficient extent, the fires are allowed to die out. The domes, after cooling, are lifted off, and the attached hemispherical cakes or ‘bells’ of SAL AMMONIAC or HYDROCHLORATE OF AMMONIA at once removed. These vary from 2 to 5 inches in thickness, and from 45 or 50 lbs. to 1000 lbs., and upwards, in weight, according to the size of the sublimers in which they have been produced. They are generally nearly pure, except in the outer part which has been in contact with the metal. From the subliming-house they are taken to the store or packing-house, and after having been scraped, to remove the discoloured portion before alluded to, are either preserved entire, or are broken up into convenient pieces, which are then packed in casks or barrels, and in either state are ready for the market.

When sulphuric acid [49] is used to neutralise the ammoniacal liquor, the process is generally, for the most part, the same as when hydrochloric acid is employed; but here the brown salt obtained by the crystallisation, and subsequent desiccation, is crude SULPHATE OF AMMONIA, instead of the hydrochlorate. It is intimately mixed with about an equal weight of chloride of sodium (common salt) before being put into the sublimers.

In some cases, particularly where the ammoniacal liquor is rich in carbonate of ammonia, gypsum is employed as a source of sulphuric acid. (See below.)

Another method is to convert the solution of the crude sulphate into a solution of the hydrochlorate, during the process, by the addition of chloride of sodium. Both these last methods are described below.

2. From BONE-LIQUOR, &c.[50]—The ammoniacal liquor technically called ‘bone-liquor’ or ‘bone-spirit,’ and formerly known under the name of ‘spirit of hartshorn,’ is essentially a solution of carbonate of ammonia more or less contaminated with volatile empyreumatic oil. Its conversion into SAL AMMONIA may be easily effected by saturating it with hydrochloric acid, evaporating the resulting neutral solution in lead or iron boilers until a pellicle begins to form, then pumping or running off the hot liquors into the crystallisers, and, lastly, draining and drying the crystals. The salt thus obtained may be purified either by sublimation or by recrystallisation. The whole series of processes closely resemble those already described, except in being less troublesome, owing to the absence of the tarry and other foreign matters which impede and complicate them when gas-liquor is employed.

[50] That employed in England is chiefly obtained, as already mentioned, from the manufacturers of bone-black or animal charcoal; but, on the Continent, the liquor obtained by a like destructive distillation of various animal offals (blood, flesh, horn, hoofs, woollen rags and waste, hair, scrapings of hides, leather cuttings, &c.) is employed for the same purpose. The preparatory process by which this liquor is obtained is essentially the same in each case; except that with animal offal the temperature should not exceed a red-brown heat, in order that the resulting charcoal may afterwards serve to make ferrocyanide of potassium and Prussian blue. These liquors have usually a density ranging between 8° and 9° Baumé (Ure; = sp. gr. 1·056 to 1·063).

Another method adopted, particularly on the Continent, and one equally applicable to any crude ammoniacal liquor rich in free ammonia or its carbonates, is to employ sulphate of lime instead of sulphuric acid to neutralise the alkali. For this purpose the ammoniacal liquor is passed through a series of three or four covered wooden filters lined with lead, each containing a layer of crushed gypsum to the depth of 3 or 4 inches. These filters are usually set on ‘stages’ one above another, and each communicates with a cistern placed beneath it by means of a leaden pipe furnished with a stop-cock. This last is not opened untill the liquor has remained some little time in the filter; and a pump throws back once, or oftener, upon each filter, what has already passed through it, before it is allowed to run into the next lower one. The ‘liquor’ in each filter is not allowed to stand higher than from 2 to 3 inches above the surface of the gypsum; and the lowest or last filter is supplied with fresh gypsum at each separate charge of fresh liquor. A little water is lastly passed through the filters to wash out the portion of ammoniacal liquor absorbed or retained by the filtering media. In this way the gypsum of the filters is converted into carbonate of lime at the expense of the carbonate of ammonia in the solution; whilst the ammonia of the latter decomposes the gypsum, and becomes converted into sulphate of ammonia, which, with some free ammonia, is found in the filtrate. Sulphuric acid is next added to the filtered liquor to completely neutralise the free and carbonated alkali still existing in it; after which it is evaporated in a leaden boiler, with133 frequent skimming to remove floating oil, until of the sp. gr. 1·160. Chloride of sodium (common salt), in sufficient quantity to convert all the sulphate of ammonia in the liquid into hydrochlorate, by double decomposition, is now added, with constant stirring; after which the clear portion is either pumped or syphoned off into a somewhat deep reservoir or tank, where it is allowed to settle. The liquid after sufficient repose is pumped from the reservoir to the boilers, and evaporated, with frequent agitation, so long as the sulphate of soda now existing in it falls to the bottom in granular crystals. These crystals are, at intervals, scraped to the cooler portion of the pan or boiler, whence they are removed by copper rakes and shovels, into draining-hoppers, placed near the edges of the pan. The liquor in the boiler is now a strong solution of sal ammoniac, but still containing a little sulphate of soda, from which it has to be freed by crystallisation. With this object it is further concentrated, and then run or pumped into the crystallisers. In 30 or 40 hours, or longer, the mother-liquor is run or pumped off. The mass of newly-formed crystals is then drained, and slightly washed, first with a little weak solution of sal ammoniac, and next with a very little cold water; after which they are again well drained. The crude HYDROCHLORATE OF AMMONIA, thus obtained, is converted into the pure salts, by desiccation and sublimation, as before.

In France, where this method is very generally employed, the sublimation is commonly conducted in stoneware or earthenware balloons or bottles coated with loam, of about 18 to 20 inches in height in the body, and either surmounted with inverted ‘cups’ or ‘heads’ 10 or 12 inches high, or simply covered with a tile, when (in the latter case) the sublimate collects in the upper part or neck of the balloon, which is above the action of the fire. A number of these vessels are set on the dome of a furnace, which is perforated with holes or slits, to allow the heat to pass through; whilst their necks or heads are sheltered from the action of the fire by plates of iron or earthenware, having semi-circular indentations on their edges, so that when placed together they form a level surface, through which the necks of the sublimers protrude, and fit closely. The fire is nicely regulated, so as to cause the salts to condense in the upper and cooler part of the vessels, or in the heads, as the case may be; and great care is taken to occasionally clear the necks with a skewer, to prevent choking, and consequent bursting.

In Scotland, where a similar process is also commonly pursued, the sublimers, according to Dr Ure, are generally “cast-iron pots, lined with fire-proof tiles; the condensation being effected in globular heads of green glass, with which each of the iron pots are capped.”[51]

Ratio. Gas-liquor contains carbonate of ammonium (chiefly), with chloride, sulphate, hydrosulphate, cyanide, sulphocyanide, &c., of the same radical. On neutralisation with hydrochloric acid, or sulphuric acid, these are converted into chloride or sulphate of ammonium, according to the acid used. By sublimation with chloride of sodium, the sulphate of ammonium is converted, by double decomposition, into chloride of ammonium, which sublimes; and sulphate of sodium, which remains in the subliming pot. A similar change occurs when the solution of the sulphate, prior to crystallisation, is decomposed by the addition of chloride of sodium, or any other chloride. When the ‘gas-liquor’ is at once converted into chloride of ammonium by the addition of hydrochloric acid, the sublimation merely purifies the salt. Like changes occur when bone-spirit is employed.

Comp. Chemically considered, this salt consists of equal VOLUMES of gaseous ammonia and hydrochloric acid gas condensed into the solid form; or, by WEIGHT, according to the ammonia-theory, of—

	Atoms.	Equiv. wt.	Per cent.
Ammonia (NH₃)	1	17·	31·78
Hydrochloric acid (HCl)	1	36·5	68·22
	——	———	———
Hydrochlorate of Ammonia (NH₃HCl)	1	53·5	100·

	Atoms.	Equiv. wt.	Per cent.
Ammonium (NH₄)	1	18·	33·65
Chloride (Cl)	1	35·5	66·35
	——	———	———
Chloride of Ammonium (NH₄Cl)	1	53·5	100·

Prop. &c. The sal ammoniac of commerce is found under the form of large white hemispherical, cup-like cakes or masses (or in large fragments which are sections of them), possessing a tough, fibrous, semi-crystalline texture, and very difficult to powder. It is odourless, has a saline taste somewhat sharp or acrid, and sublimes without either fusion or decomposition. It slightly reddens litmus; dissolves in rather less than 3 parts of cold water, and in about 1 part of boiling water; is soluble in alcohol; and when crystallised from water, under favorable circumstances, forms distinct octahedra, or cubes, usually small and aggregated together in rays or feathery masses. By slowly evaporating its aqueous solution, it may be sometimes obtained in cakes an inch in thickness. It is anhydrous. Sp. gr. 1·450.

Pur. It should give a colourless solution with water; wholly sublime with heat; and neither chloride of barium, nor sulphuretted hydrogen, should affect its solution. A solution,134 to which a few drops of nitric acid have been added, should not yield a blue precipitate with ferrocyanide of potassium. It often contains sesquichloride of iron, and sometimes lead; both of which may be readily detected by the above tests. Its complete volatility may be easily determined by heating, in the flame of a candle, a small fragment held on the point of a knife.

Tests.—1. It is known to be a salt of ammonium by its cooling ammoniacal fumes when triturated with lime, or when moistened with caustic potassa or soda:—2. It is shown to be a chloride by its solution yielding, with nitrate of silver, a white curdy precipitate, insoluble in boiling nitric acid, soluble in ammonia.

Uses, &c. In the arts, chiefly in the coating and soldering of metals, and the preparation of alloys; in dyeing; and in the manufacture of ammonia-alum; also, in large quantities, to give a factitious pungency to snuff. In chemistry, as a reagent; and, owing to the cold produced during its solution, to form frigorific mixtures. In medicine it is chiefly used externally, as a stimulant and resolvent or discutient; and occasionally, internally, as a diuretic, stimulant, resolvent, alterative, tonic, &c., particularly in chronic inflammations of the mucous and serous membranes, in chronic glandular and visceral enlargements and indurations, and in amenorrhœa. In rather large doses, frequently repeated, it is said to prove often highly beneficial in chronic enlargement and induration of the prostate gland (M. René Vanoye); and also in other like cases.—Dose, 5 to 20 gr., 3 or 4 times daily, either in powder or solution, mixed with some demulcent; as a discutient or resolvent lotion, 1 to 1¹⁄₂ oz., to ¹⁄₂ pint of water, either with or without 4 or 5 fl. oz. of spirits or strong vinegar (often serviceable in chilblains); as a weak lotion, or a collyrium or injection, 1 to 4 dr., to water, 1 pint. In very large doses it is poisonous; the treatment is emetics and mucilaginous or demulcent drinks.

Concluding remarks, Patents, &c. The methods already described are those by which commercial hydrochlorate of ammonia is usually if not almost entirely obtained; the various improvements or modifications, from time to time introduced, affecting chiefly the minor details, and the form or size of the apparatus and machinery employed, and not the general principles on which the processes are based. One of the most important of these has for its object the entire removal of the iron present in the crude salt, some of which, if it be not removed before sublimation, is volatilised and contaminates the ultimate product. To obviate this evil, Mr Brewer passes a few bubbles of chlorine through the hot concentrated solution of the salt, previous to its crystallisation; by which the protochloride of iron is converted into the perchloride, which, being acted on by the ammonia always present in the liquor, is precipitated as ferric hydrate, with the formation of a small additional quantity of sal ammoniac. The only precaution necessary is to avoid employing more chlorine gas than is necessary to peroxidise the iron; as beyond this a portion of the ammonia-salt itself is decomposed, with the evolution of nitrogen. The temperature of the liquor is kept up, after the action of the chlorine, until the whole of the brown flocculent oxide of iron has subsided, when it is at once decanted or filtered into the crystallisers.

Another modification which has been adopted in two or three places is to effect neutralisation of the crude ammoniacal liquor by distilling it, and passing the fumes in at the lower end of a hollow shaft or column filled with coke, down which the acid trickles; the resulting solution of sulphate or chloride of ammonium being received in proper cisterns, conveniently situated near the base of the column.

In Mr Spence’s method of obtaining ammonia-salts from gas-liquor or bone-spirit, a series of (usually four) cylindrical boilers, or reservoirs, so placed that the contents of each upper one may be drawn off into the one next below it are employed. Each boiler has an exit-pipe which carries the vapour generated in it to that next above it, whilst that of the highest boiler passes off to a trunk containing the acid necessary to form the salt. The top boiler is connected with the reservoir of gas-liquor (which is already mixed with milk of lime) by a charging pipe furnished with a stop-cock turned by a floating ball, so as to keep the surface of the liquor constantly at the same height. High-pressure steam enters the lower boiler, by which its ammonia is driven through the connecting pipe into the next boiler, and so on in succession, until it leaves the highest boiler in a concentrated state, and thus enters the acid-tank. When this last contains moderately strong hydrochloric or sulphuric acid, the resulting solution of CHLORIDE or SULPHATE OF AMMONIUM (as the case may be) is sufficiently concentrated to be at once run off into the crystallisers. As soon as the liquor in the lowest boiler is exhausted of its ammonia, its contents are drawn off, and replaced by that of the next boiler, which is followed by a like descent throughout the whole series.

Among improvements having for their object the substitution of cheap chlorides [52] for the more expensive commercial acids, may be mentioned those of—

1. Mr Laming (Patent dated 1843), who employs a strong solution of CHLORIDE OF CALCIUM for converting the ammonia of gas-liquor into the hydrochlorate.

2. Mr Hills (Patent dated 1846) employs CHLORIDE OF MAGNESIUM [53] in the same way; and by a subsequent patent proposes to convert the ammonia eliminated in the distillation of135 coal into the hydrochlorate, by mixing CHLORIDE OF MAGNESIUM with the coal in the retorts, or by introducing the chloride into a retort appropriated for the purpose. The heat dispels the chlorine of the chloride, in the form of hydrochloric acid, and this, uniting with the ammoniacal vapour, forms hydrochlorate of ammonia, which is retained in the liquor of the condenser. From this liquor the salt is obtained by evaporation, &c., in the usual way.

3. Mr Croll (Patent dated 1849) converts the crude ammoniacal vapours that issue with the gas from the common retorts into the hydrochlorate, and obtains a solution of it by passing the gas through a solution of crude CHLORIDE OF MANGANESE [54] (1 cwt. of the salt to about 40 galls. of water), contained in one of the ordinary vessels used for purifying coal-gas. The manganic solution absorbs the ammonia and its salts, converting them into the hydrochlorate, whilst a corresponding proportion of oxide of manganese is precipitated. As soon as the liquor in the purifier is fully saturated, it is drawn off, and replaced by a fresh quantity; whilst the saturated liquor containing the hydrochlorate, after subsidence, or filtration, is evaporated, &c., as before. Crude CHLORIDE OF IRON may be substituted for the chloride of manganese, in the above process: as may also SULPHATE OF MANGANESE, but then the product, of course, will be sulphate of ammonia, instead of the hydrochlorate.

4. Mr Laming (Patent dated 1850) also proposes the use of various salts and mixtures for retaining and condensing the ammoniacal vapour of coal-gas as it passes from the retorts through the purifiers. Of these the principal are CHLORIDE OF CALCIUM obtained by decomposing chloride of iron by hydrate of lime; CHLORIDE OF IRON, obtained by decomposing sulphate of iron with chloride of sodium; CHLORIDE OF MAGNESIUM; a mixture of SULPHATE OF LIME and SULPHATE OF IRON; or of moist precipitated oxide of iron with carbonate of lime, carbonate of magnesia, or magnesian limestone; or one containing sulphate of magnesia, or chloride of magnesium or calcium, or one or more of them, in combination with oxide of copper, either with or without lime or magnesia, or with both or either of them or their carbonates. These salts, or compounds, are mingled with sawdust, or some other porous substance not acted on by the gas, before being put into the purifiers; and after they become saturated with the vapour, the newly-formed hydrochlorate or sulphate (according to the salt or mixture employed) is washed out of the mass with water.

Besides the usual sources of SAL AMMONIAC (and the other ammonia-salts of commerce) it has been proposed to obtain it from guano, peat, shale, &c., as noticed under Sesquicarbonate of Ammonia (suprà); the substance employed to effect the neutralisation or decomposition of the ammoniacal liquor being, in this case either hydrochloric acid or a chloride.

In Young’s Patent (1841) for ‘obtaining AMMONIA and its SALTS,’ a mixture of 2 parts of guano, and 1 part of hydrate of lime, is distilled in a retort placed vertically, at a moderate heat, gradually increased until the bottom of the retort becomes red hot. The ammoniacal portion of the fumes evolved are absorbed by the cold water contained in a suitable condenser; whilst the other gases eliminated by the process pass off uncondensed. By subsequently passing carbonic acid gas into the liquor of the condenser, a solution of CARBONATE, BICARBONATE, or SESQUICARBONATE of AMMONIA is formed. By nearly filling the condenser with diluted hydrochloric or sulphuric acid, instead of with water, a solution of HYDROCHLORATE or of SULPHATE of AMMONIA is obtained.

Stale urine saturated with hydrochloric acid, or with sulphuric acid diluted with about twice its weight of water, yields SAL AMMONIAC, or SULPHATE OF AMMONIA (according to the acid used) on evaporation.

Hydrochlorate of ammonia is now wholly prepared on the large scale, and never by the dealer or retailer, by whom it is only occasionally refined or purified, in small quantities, for chemical and medical purposes. The sal ammoniac of commerce is found to be sufficiently pure for all its ordinary applications in the arts; but when wanted of greater purity, it is broken into pieces, and resublimed from an earthenware vessel into a large receiver of earthenware or glass. The product (REFINED SAL AMMONIAC, DOUBLE-REFINED S. A.; AMMONIÆ HYDROCHLO′′RAS PU′′RA, SAL AMMONI′ACUS DEPURA′TUS†, L.) is popularly known as FLOWERS OF SAL AMMONIAC (flo′res sa′lis ammoni′aci, L.), from being in a finely divided crystalline state.

The chemically pure chloride of ammonium may be prepared by bringing its gaseous constituents—ammonia and hydrochloric acid—into contact. During the combination much heat, and even light, is generated, and the anhydrous solid salt is precipitated in a minutely divided state, which, under the microscope, is seen to be crystalline. It may be also more easily and conveniently prepared by saturating pure and moderately dilute hydrochloric acid with ammonia or its carbonates, and evaporating the solution until a pellicle forms, when crystals of the chloride separate as the liquid cools. A similar but rather more violent reaction occurs when gaseous chlorine136 is brought in contact with gaseous ammonia, or is passed into a nearly saturated solution of ammonia or its carbonates; but in this case nitrogen is evolved at the expense of the ammonia; moreover, the process is attended with danger.

The manufacture of sal ammoniac is usually a distinct business, and is carried on to a very great extent in the neighbourhood of London. Indeed, the London makers now supply the chief portion of that used in England. A large quantity is now, however, made at Manchester and Liverpool. A small quantity is imported from Germany. That from Brunswick is in the form of sugar-loaves. An inferior quality is also imported, in chests, from the East Indies.

The red bands frequently seen in the sal ammoniac of commerce are said to arise from the workmen falling asleep, and allowing the fire to go down, and then suddenly raising the heat too high. (Muspratt.) They consist chiefly of ammonio-chloride of iron.

Ammonium, Citrate of. (NH₄)₂HC₆H₆O₇. Syn. Diammonium citrate, Citrate of oxide of ammonia; Ammon′′niæ cit′ras, L.

Prep. A concentrated solution of pure citric acid, gently heated, is saturated with sesquicarbonate of ammonium, in fine powder (about 7 parts to 6), and slightly in excess; and the resulting liquid is crystallised by refrigeration in close vessels, or by evaporation in vacuo. If heat be employed in the evaporation of the solution, an acid citrate will be formed.

Uses, &c. Chiefly as a chemical test. An extemporaneous citrate, made with lemon-juice and drunk effervescing, is employed as a saline draught, and a mild aperient and diaphoretic, in fevers, &c.

Ammonium, Ferrocyanide of. (NH₄)₄ FeC₆N₆ . 3Aq. Syn. Ferrocyanate d’ammoniaque, Fr. Prep. 1. Saturate a solution of hydroferrocyanic acid with sesquicarbonate of ammonium, in slight excess; evaporate the solution at a heat below ebullition, and crystallise by refrigeration.

2. Digest ferrocyanide of lead or of iron in a solution of sesquicarbonate of ammonium, at a gentle heat, for some time; then filter, evaporate, and crystallise.

Prop., &c. It is isomorphous with ferrocyanide of potassium; it is easily crystallisable, very soluble in water, and is decomposed by ebullition.

Ammonium, Iodide of. NH₄I. Syn. Hydriodate of ammonia; Ammo′′nii iodi′dum, L.; Hydriodate d’ammoniaque, Fr. Prep. An aqueous solution of hydriodic acid is neutralised with ammonia, or ammonium sesquicarbonate, in slight excess; and the resulting liquid is either carefully, but rapidly, evaporated to dryness over a water bath, or it is concentrated by the same means, and then caused to deposit crystals by refrigeration; in both cases care is taken to keep a slight excess of ammonia present during the evaporation. The crystals are dried by pressure between folds of bibulous paper; and the product, in either form, preserved in a stoppered bottle.

Pure iodine is triturated with a little distilled water, and solution of ammonium sulphydrate added, in small quantities at a time, with continued trituration, until the red colour of the iodine has entirely disappeared. The solution, after being gently boiled for a few seconds, to expel the sulphuretted hydrogen present, is filtered, slightly alkalised, with ammonia, and evaporated or crystallised, as before.

Prop., &c. Colourless; deliquescent; freely soluble in water, and in spirit; air and light turn it yellowish or brownish, with partial decomposition. It closely resembles iodide of potassium, than which it is more active, and thought to be better suited to irritable and relaxed habits.—Dose, 1 to 10 or 12 gr.

Ammonium, Lac′tate of. Syn. Ammo′′niæ lac′tas, L. An uncrystallisable salt prepared by saturating ammonia, or its carbonate, with lactic acid. It has been found useful in rickets, and in dyspepsia and worms, when occurring in debilitated habits. For this purpose it is best taken fresh-prepared, as a draught, flavoured with syrup of orange-peel, 3 or 4 times daily. See Lactate and Lactic Acid.

Ammonium, Nitrate of. NH₄NO₃. Syn. Ammo′′niæ ni′tras, L.; Nitrate d’ammoniaque, Fr. Prep. Saturate nitric acid (diluted with 3 or 4 times its weight of water) with sesquicarbonate of ammonium, evaporate by a gentle heat, and crystallise. When not required in a crystalline form, it is usually evaporated to dryness at about 212° Fahr.; and the heat being carefully raised to about 250°, the fused salt is poured out on a polished slab of iron or stone, and when solidified broken up and put into bottles.

Prop. When the evaporation of the solution is conducted at a heat under 100° Fahr., the salt is obtained in beautiful hexagonal prisms; when at 212°, in long silky fibres; when by rapid evaporation and fusion, it forms a white, compact, and usually foliated mass. It dissolves in about twice its weight of water; is slightly deliquescent; melts at 230°, and is decomposed into nitrous gas and water at 460° Fahr. It deflagrates, like nitre, on contact with heated combustible matter.

Uses, &c. Chiefly to prepare nitrous oxide or laughing gas (of which nearly 4¹⁄₂ cubic feet may be procured from every lb. avoir.); and with water, to form freezing mixtures, for which purpose it may be used for any number of times by simply evaporating the solution to dryness, when the salt, obtained unaltered, is ready for another operation. Care, however, should be taken not to expose it to too great a heat, as at a certain temperature it deflagrates with violence. It is occasionally employed in the laboratory to promote the combustion of organic bodies during incineration; and sometimes, though seldom, in medicine, as a diuretic137 and diaphoretic. It is said to reduce the frequency of the pulse, and the animal heat, without affecting the head, chest, or stomach. (Wibmer.)—Dose, 10 to 30 gr.

Ammonium, Nitro-sulphate of. Syn. Ammo′′niæ nitro-sul′phas, L. Dissolve sulphite of ammonium, 1 part; in solution of ammonia, 5 parts; and pass nitric oxide gas through the solution; rapidly wash the crystals that form with solution of ammonia, dry in bibulous paper, without heat, and preserve them in a well-stopped bottle.—Dose, 10 to 20 gr.; in typhoid fevers, &c.

Ammonium, Oxalate of. (NH₄)₂C₂O₄. Syn. Ammo′′niæ ox′alis, L.; Oxalate d’ammoniaque, Fr. Neutralise a hot solution of oxalic acid with sesquicarbonate of ammonia; evaporate and crystallise.

Prop. It forms beautiful, colourless, long, rhombic prisms, which effloresce in the air; slightly soluble in cold water; freely soluble in hot water; heated in a retort, it yields ammonia, carbonate of ammonia, cyanogen, and carbonic acid, together with oxamide, which sublimes.

Uses, &c. In chemistry, chiefly as a test for calcium (with which it produces a white precipitate soluble in nitric acid), and to separate lime from magnesium, solutions of the salt of which it does not precipitate. A BINOX′ALATE may also be formed; but it possesses no practical interest.

Ammonium, Phosphate of. (NH₄)₃PO₄. Syn. Ammo′′niæ phos′phas, L. Prep. Saturate a solution of phosphoric acid with sesquicarbonate of ammonium, in slight excess; gently evaporate and crystallise by refrigeration. Diuretic, discutient, and antilithic.—Dose, 3 to 10 gr., or 20 to 30 drops of a saturated solution, 3 or 4 times a day; in gout, rheumatism, and calculus, accompanied with the lithic-acid diathesis; also in rickets and certain forms of dyspepsia.

Ammonium Suc′cinate. Syn. Ammo′′niæ suc′cinas, L. Prep. 1. Succinic acid, 1 part; water, 4 parts; dissolve, neutralise with solution of ammonia, or of ammonium carbonate, in slight excess, and evaporate, and crystallise as directed under the ‘benzoate’ or ‘phosphate,’—Dose, 2 to 10 gr.

Ammonium, Sul′phate of. (NH₄)₂SO₄. Syn. Sulphate of ox′ide of ammonia; Ammo′′niæ sul′phas, L,; Sulfate d’ammoniaque, Fr.; Schwefelsauer ammonium salz, Ger.; Glauber’s Secret salt†, G. SECRET SAL AMMONIAC†, Sal ammoni′acum secre′tum Glaube′′ri†, &c. Crude sulphate of ammonia exists in considerable quantity in the soot from pit-coal; and it is obtained, as a secondary product, from the ammoniacal liquor of gas-works and animal charcoal manufactories. These last are its chief sources. It is also found native, associated with sal ammoniac, in the neighbourhood of volcanoes, under the name of ‘mascagnine’ or ‘massagnine,’

Prep. 1. (Medicinal.) Saturate dilute sulphuric acid with sesquicarbonate of ammonia, in slight excess; filter, gently evaporate, and crystallise.

2. (Commercial.) From gas-liquor or bone-spirit, saturated with weak oil of vitriol, and, the clear portion of the liquid, after repose decanted, concentrated by rapid evaporation, and crystallised, in the manner noticed under Ammonium, Chloride of.

Prop. Crystals, long, flattened, six-sided prisms; soluble in 2 parts of cold, and 1 of boiling water; fuses, with loss of one atom of water, at about 280° Fahr.; and is volatilised, with entire decomposition, at about 535°. Even its solution, by long boiling, becomes acid from loss of ammonia. The anhydrous salt does not exist.

Uses, &c. Pure sulphate of ammonia is diuretic, aperient, resolvent, and stimulant.—Dose, 10 to 30 gr. It is now seldom employed in medicine. The crude sulphate is principally used in the preparation of sal ammoniac and sesquicarbonate of ammonia, and for manure. “A mixture of 10% of this sulphate with 20% of bone-dust, some gypsum, and farm-yard manure, forms a very fertilising compost, applicable to a great variety of soils” (Ure); and we may add—greatly superior to a very large portion of what is now so commonly vended under the name of ‘guano.’

Concluding remarks, Patents, &c. The manufacture of sulphate of ammonia, on the large scale, has been unavoidably explained in treating on the salts of that base already noticed. All that is necessary is to saturate with sulphuric acid the solution of ammonia, crude or otherwise, and obtained in any manner; and then to evaporate the solution until the salt crystallises out. At other times, however, instead of adding the acid to the ammoniacal liquor, the latter, either at once, or after treatment with lime, is submitted to distillation, and the evolved alkaline vapour is passed into the acid (previously somewhat diluted), contained in a large receiver or cistern, or a series of them; the salt being obtained from the resulting solution in the usual manner. By re-solution and a second crystallisation the sulphate is generally obtained sufficiently pure for all commercial purposes; but when the salt is intended for use as manure, or (unless very rough) for conversion into sal ammoniac, this need not be had recourse to.

Among modifications and improvements, not previously noticed, may be mentioned—

1. That of Dr Richardson (Patent dated Jan., 1850), who mixes SULPHATE OF MAGNESIA with the crude ammoniacal liquor, and thus forms a double sulphate of magnesia and ammonia, from which he obtains the SULPHATE OF AMMONIA by sublimation.

2. That of Michiel (Patent dated April, 1850), who prepares sulphate of ammonia by means of OXYSULPHATE OF LEAD obtained by roasting galena (sulphide of lead), by exposing it in a crushed state and thin layers for 2 or 3 hours,138 to the heat of a reverberatory furnace. The resulting mixture of sulphate and oxide of lead is reduced to the state of coarse powder, and well worked up with the ammoniacal liquor, when SULPHATE OF AMMONIA and sulphide and carbonate of lead are produced by the mutual reaction of the elements present. The first is removed by treatment with water; and the residuum serves for the manufacture of lead compounds, or may be reduced to the metallic state by fusion in the usual manner.

3. That of Mr Laming (Patent dated Aug., 1852), in which a stream of SULPHUROUS ACID GAS is transmitted through the liquor containing the ammonia, either in the free state or as carbonate, by which SULPHITE OF AMMONIA is formed. This salt he oxidises, and thus converts into the SULPHATE OF AMMONIA, by agitation and free exposure to the air.

Sulphate of ammonia, like the hydrochlorate, may also be obtained by saturating stale urine with the acid, and subsequent evaporation and crystallisation. See Ammonia; Ammonia, Carbonates of; Ammonium, Chloride of, and Manures, &c.

Ammonium, Sulphide of (neutral). (NH₄)₂S. Prep. Saturate strong solution of ammonia with pure sulphuretted hydrogen gas; then add a second portion of solution of ammonia, equal to that first used, and preserve it in a well-stoppered bottle.

Ammonium, Sulphydrate of. NH₄HS. Syn. Sulphide of ammonium, Hydrosulphide of ammonium, Hydrosulphate of ammonia. Prep. By passing sulphuretted hydrogen gas, to saturation, through a mixture composed of strong solution of ammonia, 1 part, and distilled water, 4 parts.

Props. Prepared as above, it has a very fœtid odour. When pure it is wholly volatilised by heat, and does not disturb a solution of sulphate of magnesium. Mineral acids decompose it, with the evolution of sulphuretted hydrogen. By keeping, it decomposes and acquires a yellow colour. This yellow coloration does not, however, render it unfit for use as a reagent; but it must be borne in mind that it will now deposit sulphur when mixed with acids. In this state it proves valuable as a reagent to detect hydrocyanic acid, and as a solvent to separate metallic sulphides thrown down by sulphuretted hydrogen.

Uses, &c. It is principally employed by chemists as a reagent to precipitate metals, to separate metallic sulphides, &c.; and by the perfumers as a mordant in dyeing hair. In medicine it has been used by Cruickshank, Rollo, and others, to check the morbid appetite, and to increase the action of the stomach and general tone of the system in diabetes mellitus. It has also been used by Brauw, Gruithuisen, and others, in old pulmonary and vesical catarrhs. It is a powerful sedative, lessening the action of the circulatory system, causing nausea, vomiting, vertigo, drowsiness, &c.—Dose, 3 to 6 drops, three or four times daily, mixed with pure water, and instantly swallowed. In large doses it is poisonous.

Ant. Very dilute solution of chlorine, or of chloride of lime or soda, followed by a powerful emetic, or the stomach-pump. When the vapour has been respired, free exposure to fresh air, with the head a little elevated, and copious affusions of cold water, with moderate draughts of brandy-and-water, and the use of the smelling-bottle (ammoniacal) should be adopted. If need be, artificial respiration should be attempted, and the air around the patient should be slightly impregnated with the fumes of chlorine or chloride of lime.

Ammonium, Persulphide of. Syn. Boyle’s Fuming-liquor, Hoffman’s Vol′atile spirit of sulphur, &c.; Ammo′′niæ perhydrosul′phas, A. perhydrosulphure′tum, &c. Authorities differ as to the constitution of this liquid, which, since its introduction by Beguin in 1650, has passed under more ‘aliases’ than perhaps any other preparation. Its precise position amongst the ammonia-compounds is still undecided.

Prep. 1. (Beguin.) Sulphur, 1 lb; quick-lime, ¹⁄₂ lb; sal ammoniac, 4 oz.; mix and distil.

2. (Boyle.) Sulphur and sal ammoniac, of each, 5 oz.; quick-lime, 6 oz.; as last.

3. (Liebig.) Agitate the common hydrosulphate of ammonia with pure sulphur, until the latter ceases to be dissolved; and, after repose, decant the clear liquid.

Prop., &c. An orange-yellow, fuming, fœtid liquid, of an oily consistence, having the characteristics of the common sulphydrate in a remarkable degree. It may prove an excellent medicine. “Useful for wounds and ulcers.” (Beguin.) Diluted with three parts of spirit of wine, it formed the LIQUOR ANTIPODAG′RICUS of F. Hoffman; of which we are told that about 30 drops acted as a strong sudorific; and applied externally, mixed with camphor, “it relieved pain like a charm.” (Hoffman.) The sulphides of ammonium are now scarcely ever employed as remedies.

Ammonium, Sul′phite of. (NH₄)₂SO₃.7Aq. Syn. Ammoniæ sulphis, L. Prepared by passing sulphurous acid gas into a solution of ammonia. It is crystallisable and very soluble in water.

Ammonium, Sulphocyanide of. NH₄CNS. Prep. 1. Neutralise hydrosulphocyanic acid with ammonia, and gently evaporate the solution to dryness, by the heat of a water bath.

2. Digest hydrocyanic acid with yellow sulphydrate of ammonium, and, after a time, evaporate as before.

A deliquescent, white, saline mass, very soluble in water, but seldom employed out of the laboratory in a pure state. Of late it has been obtained in quantity as a crude product of the gas-liquors.

Ammonium, Neutral Tartrate of. (NH₄)₂C₄H₄O₆. Syn. Ammo′′niæ tar′tras, L. Prep.139 Saturate a solution of crystallised tartaric acid, 150 grs.; with sesquicarbonate of ammonium, 118 grs.; and either evaporate the solution at a gentle heat, and crystallise; or evaporate to dryness, and powder the residuum.

Prop., &c. Prismatic crystals, or a crystalline mass; soluble and efflorescent. Its medicinal properties and doses resemble those of citrate of ammonium.

Ammonium, Bitartrate of. NH₄HC₄H₄O₆. Syn. Ammo′′niæ bitar′tras, L. Prep. To a strong solution of tartaric acid add another of sesquicarbonate of ammonium, or of tartrate of ammonium, as long as a precipitate falls; which must be collected and dried.

Prop., &c. A crystalline powder, only slightly soluble in water, closely resembling ordinary cream of tartar. It is diaphoretic, diuretic, and deobstruent, and is frequently, though improperly, sold for the preceding preparation.

Ammonium, Valerianate of. NH₄C₅H₉O₂. Syn. Ammo′′niæ valeria′nas, L. Prep. Saturate valerianic acid with strong solution of ammonia, and evaporate the resulting liquid to a syrupy consistence at a heat under 175° Fahr.; then add twice its volume of alcohol, and, after agitation, allow it to crystallise by spontaneous evaporation.—Dose, 2 to 8 or 10 gr.; in neuralgia, epilepsy, hypochondriasis, hysteria, low fevers of an intermittent kind, &c.; also in dyspepsia and debility complicated with these affections.

AMMONI′ACAL. [Eng., Fr.] Syn. Ammoniaca′lis, L. Pertaining to, or possessing the odour or properties of, ammonia. See Ammonia, &c.

AMMONI′ACUM. Syn. Gum ammoniacum, G. ammo′′niac†; Gomme ammoniaque, Fr.; Ammoniak, Ger. A gummy-resinous exudation from the stem of dorema ammoniacum, in tears and masses, of a pale cinnamon colour, brittle, and when broken has a white and shining surface. Collected in Persia and the Punjaub. (B. P.)

Gum ammoniacum has an unpleasant odour, especially when heated, and a nauseous and slightly bitter taste. It is a mild, stimulating expectorant and emmenagogue; and its effects on the system resemble those of assafœtida except in being weaker. Externally, it is resolvent.—Dose, 10 to 30 gr. in pills or emulsion.

Doses for Animals. Horse, 2 to 4 drachms. Cattle, 2 to 4 drachms. Sheep, ¹⁄₂ to 1¹⁄₂ drachm. Pig, ¹⁄₂ to 1¹⁄₂ drachm. Dog, 10 to 20 grains. Either by bolus or emulsion.

Ammoniacum, Strained′. Syn. Prepared ammoniacum; Ammoni′acum præpara′tum (Ph. L.), L. Prep. (Ph. L. 1851.) Boil ammoniacum in water just sufficient to cover it; strain the mixture through a hair sieve, and constantly stirring, evaporate in a water bath, until, on cooling, it becomes hard. The product, owing to a loss of volatile oil, is much weaker than the unprepared gum-resin. The process is only necessary with rough lump ammoniacum.

Ammo′′niated. Syn. Ammonia′tus, L. In pharmacy, perfumery, &c., applied to preparations containing ammonia.

AMMO′NIO-, Ammon′ico-. In chemistry, a common prefix to double salts containing ammonia; as ammonio-citrate, a.-chloride, or a.-tartrate of iron, &c. See the respective metals.

AMORPH′OUS (-morf′-us). Syn. Amorph′us, L.; Amorphe, Informe, Difforme, Fr.; Amorphisch, Misgebildet, Missgestaltet, Ger. Shapeless. In chemistry and mineralogy, applied to substances devoid of regular or crystalline form; as a lump of chalk, the majority of precipitates, &c. The corresponding substantives are AMORPH′ISM, AMORPH′OUSNESS* (amorphis′mus, L.; amorphisme, Fr.).

AMPHIB′IA (fĭb′-y′ă). [L. pl.; prim. Gr.] Syn. Amphib′ians (-yănz), Amphib′ials (-y′ălz). Animals that possess the faculty of living both in water and on land. In modern zoology it is restricted to those animals which possess both gills and lungs; as the batrach′ia or frog tribe. The term is also often applied, colloquially, to otters, seals, walruses, crocodiles, &c., none of which can breathe under water, although, from the languid nature of their circulation, they are able to remain a long time in it.

AMPHIB′IOUS (y′ŭs). Syn. Amphib′ius, L.; Amphibie, Fr.; Beydlebig, Ger. In botany and zoology, having the faculty of growing or living both on land and in water. See Amphibia.

AMYGDALIN. C₂₀H₂₇NO₁₁.3Aq. This substance exists in bitter almonds. It crystallises in pearly white plates, which are odourless and almost tasteless. It is nearly insoluble in hot and cold water and in cold alcohol, but soluble in boiling alcohol. To prepare amygdalin, boil well-pressed cake of bitter almonds twice in strong alcohol; strain through linen, and press the residue; remove any oil that may appear, heat the liquid again, and filter. In a few days part of the amygdalin crystallises out. Concentrate the residuary liquor to a sixth part, and add ether, which will throw down the amygdalin. Press it between blotting paper, wash it with ether, and set aside to crystallise.

AMYG′DALOID (-loyd). Syn. Amygdaloid′al; Amygdaloï′des (-dēz), L.; Amygdaloïde, Fr. Almond-shaped. In mineralogy, amygdaloid is ‘toadstone.’

AMYKOS (Galen, Upsala). A cosmetic and mouth-wash. Claims to be prepared according to an English patent. It is an aqueous extract of 420 grms. cloves, boiled in a gallon of water, in which 420 grms. of pure glycerine are dissolved, and to which 210 grms. of borax are added. (Hager.)140

AMYLA′CEOUS (ăm-e-lā′-sh′ŭs). Syn. Amyla′ceus, L.; Amylacé, Fr. Of or like starch; consisting of or abounding in starch; starchy. See Food, Nutrition, Starch, &c.

AM′YL (-ĭl). C₅H₁₁. The radical of the fusel-oil compounds (AMYL-SERIES).

Amyl, Acetate of. C₅H₁₁C₂H₃O₂. Syn. Pear-oil. Prep. From fusel-oil, 1 part; acetate of potassa (dry), 2 parts; concentrated sulphuric acid, 1 part; distilled, with the usual precautions, from a glass retort into a cool receiver. The distillate is purified by washing it with very dilute solution of potassa, and redistilling it from fused chloride of calcium. A little litharge added to the liquid in the retort, before rectification, will remove any sulphurous odour, should it be present.

Prop., &c. Liquid, limpid, colourless; insoluble in water; soluble in alcohol; boils at 272° Fahr.; alcoholic solution of potassa converts it into an acetate of that base, with reproduction of fusel-oil.

Obs. The odour and flavour of this preparation are those of the Jargonelle pear. It is now extensively manufactured, and, after dilution with alcohol, is sold under the name of ESSENCE OF JARGONELLE PEAR, for flavouring liqueurs and confectionery.

Amyl, Vale′rianate of. C₅H₁₁C₅H₉O₂. Syn. Apple-oil, A.-essence, &c. This compound is abundantly formed during the preparation of valerianic acid from potato oil, and is recognised by the offensive odour of rotten apples evolved during the process. By treating the crude product of the distillation with a weak solution of pure potassa, the valerianic acid is removed, and the volatile oil obtained nearly pure. Dissolved in rectified spirit it forms the ‘APPLE-ESSENCE’ now so much employed as a flavouring ingredient for confectionery and liqueurs. See Fruit Essences, Valerianic Acid, &c.

AMYL NITRITE. Syn. Amyl nitris, B. P. Produced by the action of nitric or nitrous acid on amylic alcohol.—Dose. By inhalation, the vapour of 2 to 5 minims. To be used with caution. It may be produced by passing a stream of nitrous acid gas through purified amylic alcohol at a temperature of 132° C.

For other methods of preparing it consult ‘Wood and Bache’s United States Dispensatory, 1877.’ Mr Umney (‘Pharm. Journal’) says that true nitrite of amyl should be made by passing nitrous acid into amylic alcohol which has been previously submitted to a fractional distillation, until the portion retained for use has a boiling point of 132° C. A nitrate so prepared, when deprived of any excess of acid it may contain by rectification over fused carbonate of potash, will have a boiling point of 98°-99° C.

AM′YLENE (-e-lēne). C₅H₁₀. [Eng., Fr.] Syn. Am′ilene*; Amyle′na, Amyle′num, L. A peculiar volatile, liquid hydrocarbon, discovered by Cahours.

Prep. From fusel-oil repeatedly distilled along with either anhydrous phosphoric acid, or a concentrated solution of chloride of zinc; the product being repeatedly rectified at a low temperature, until the boiling point sinks to 102° Fahr.

Prop., Uses, &c. An ethereal liquid, lighter than water, having an aromatic odour, slightly alliaceous. Sp. gr. of vapour, 2·68. Its vapour was several times successfully employed, by the late Dr Snow, as a substitute for ether and chloroform in producing anæsthesia, being, though less agreeable, also less pungent, and consequently easier to breathe, than either of them; but its use has since been given up owing to doubts as to its safety, two or three deaths having followed its inhalation.

ANADOLI (Kreller, Nuremburg). An oriental tooth-powder. Powdered soap, 42 parts; starch powder, 44 parts; levantine soapwort, 12 parts; oil of bergamot and lemon to flavour. (Wittstein.)

ANÆSTHE′SIA (ăn-ēz-the′-zh′ă; -sh′ă; -thēze′y′ăr). [L.; prim. Gr.] Syn. Anesthésie, Fr. In pathology, diminished or lost sense of feeling.

In surgery and obstetrics, the production of temporary anæsthesia, for the purpose of rendering operations painless, relieving the pangs of childbirth, &c., is effected by the use of—

ANÆSTHET′ICS. Syn. Anæsthet′ica, L.; Anesthétiques, Fr. In pharmacology and surgery, substances or agents which diminish or destroy sensibility, or which relieve pain. In its full extent this term includes both anodynes and narcotics; but it is now more generally confined to those substances which greatly diminish common sensibility, or entirely remove susceptibility to pain. Among the most useful, safe, and powerful of this class are chloroform, ether, nitrous oxide, and intense cold; besides several chlorinated compounds, such as the bichlorides of ethylen, methylen, and carbon.

More than 1500 years ago the Chinese are said to have used a preparation of hemp, or ma-yo, to annul the pain attendant upon cauterisation and other surgical operations. Mandragora (mandrake) was employed for a similar purpose by the Greeks and Romans; and we learn that as early as the thirteenth century the vapour from a sponge filled with tinctures of mandragora, opium, and other sedatives was used for a similar purpose.

Baptista Porta, in his work on natural magic printed in 1597, mentions a quintessence extracted from medicines by somniferous menstrua, of the nature of which he leaves us in ignorance. This quintessence was to be preserved in leaden vessels very perfectly closed, lest the aura should escape, for the medicine would vanish away. Furthermore, he adds, “when it is used, the cover being141 removed, it is applied to the nostrils of the sleeper, who draws in the most subtle power of the vapour by smelling, and so blocks up the fortress of the senses, that he is plunged into the most profound sleep, and cannot be roused without the greatest effort.” Dr Iron suggested that the volatile substance was sulphuric ether, which he says had been described more than fifty years before Porta wrote his book. In the year 1800 Sir Humphry Davy suggested the employment of nitrous oxide, or laughing gas, as it was then termed, for minor operations in surgery, and in 1828 Dr Hickman proposed carbonic acid as an anæsthetic. The vapour of sulphuric ether had been used in his practice by Dr Pearson as early as 1795, for the relief of spasmodic asthma. The fact that sulphuric ether was capable of producing insensibility was demonstrated by American physicians; viz. by Godwin in 1822, Mitchell in 1832, Jackson in 1833, and Wood and Bache in 1834; but the first practitioner to employ it to prevent the pain of an operation was Dr Morton, a Boston dentist, who successfully used it for this purpose in 1846. On the 19th of December of the same year Mr Liston, of University Hospital, London, and Mr Robinson, a dentist, operated upon patients who had been rendered insensible by means of the inhalation of the vapour of ether.

Throughout the year 1847 ether was employed as an anæsthetic both in England and France, but towards the end of that year the anæsthetic properties of chloroform were pointed out by Flourens. The first, however, to introduce this agent into surgical and obstetric practice was Dr I. T. Simpson, of Edinburgh. In 1849 a work on the inhalation of ether was published by Dr Snow, who afterwards introduced a new anæsthetic, viz. amylene, which was capable of producing effects similar to those of chloroform; but as two patients out of but a small number who inhaled the vapour of amylene died, this latter soon fell into discredit, and consequent disuse.

Except in dental practice, in which nitrous oxide gas is the anæsthetic invariably employed, chloroform is almost universally used in surgical operations, one advantage it possesses over ether being its much more rapid action, although this latter property must be regarded as one which constitutes the risk which, although very slight (when the exceedingly small per-centage of deaths resulting from its administration is taken into account), undoubtedly attends its inhalation.

Dr Sansom says of chloroform:—“The cause of its danger is its power of paralysing the cardiac and other motor sources of circulation. This property resides in large and sudden doses of its vapour.” He strongly recommends its dilution by air and alcohols. He further remarks that all anæsthetics modify the endosmotic condition of the blood discs, and contends that they affect the supply of arterial blood by altering the calibre of the channels which convey it. He advocates the substitution of one anæsthetic for another during the inhalation.

Methylene dichloride, introduced by Dr B. W. Richardson, is said to possess the disadvantage of causing considerable depression.

The mode of administering these agents is by causing the patient to inhale their vapour mixed with air.

Sometimes they are poured on to a sponge or a handkerchief, or piece of lint, either of which is then applied to the mouth and nostrils of the patient in such a manner that the air which passes into his lungs is saturated with the vapour. Except in extemporised cases, however, this method is pretty well abandoned, a proper apparatus having supplanted the sponge or handkerchief, &c. Part of the apparatus consists of a graduated bottle containing the anæsthetic, by means of which the operator is enabled to tell how much of this latter is being consumed, and thus to regulate the quantity inhaled.

The first effect that results from the administration of anæsthetics is a form of intoxication, caused by the action of the anæsthetic agent on the cerebral lobes, and as this action extends to the cerebellum, the patient becomes incapable of directing his movements—an effect like that caused by intoxication from alcohol.

In the next stage the spinal cord is attacked, unconsciousness supervenes, and all powers of motion and sensation are lost. The individual is now said to be in a state of anæsthesia; but the heart continues to beat, respiration is not impeded, and the other essential functions of the body go on as usual.

Should, however, the exhibition of the anæsthetic agent be incautiously continued too long, the bodily temperature falls, the movements of respiration and circulation become impaired, the heart ceases its action, and death finally ensues. The introduction of anæsthetics into surgical practice has been of great and invaluable service to the operator. The patient being motionless and free from pain, the surgeon is enabled to perform the operation at his ease, and consequently more efficiently; moreover, in the reduction of dislocations and of hernia, the muscles being flaccid, the obstacle produced by their contraction is removed. M. Velpeau endeavoured to produce local anæsthesia, or insensibility of the part of the body to be operated upon, by means of a freezing mixture composed of ice and salt; this method, however, was found impracticable, and was soon abandoned. Since then local anæsthesia as introduced by Dr Richardson, when had recourse to, is effected by means of a spray of ether directed on the part, the intense cold produced by the rapid evaporation of the ether entirely142 depriving the part of sensation. It is said that the pain resulting from the application of this method is a great barrier to its use.

Amongst anæsthetics, nitrous oxide gas occupies an important place, its use, as before stated, being almost wholly confined to operations in dental surgery.[55] As in the case of ether, the American practitioners were the first to employ nitrous oxide as an anæsthetic. Attention was directed to its anæsthetic properties in 1844 by Mr Horace Wells, an American dentist, but little interest seems to have been awakened by his application of it, since it was not until 1863 that Dr Cotton, of New York, drew attention to the subject by performing an operation on a patient under its influence.

In March, 1868, Dr Evans, residing in Paris, after a visit from Dr Cotton, directed the attention of medical men in England to the value of nitrous oxide as an anæsthetic in dental surgery, and shortly afterwards it was first employed to produce anæsthesia at the Dental Hospital. Nitrous oxide is obtained from nitrate of ammonia, and the particulars of its preparation may be found by referring to the article Nitrous oxide.

Immense quantities of the gas are used in dental operations. It has been computed that in 1870 Messrs Coxeter and Barth could not have prepared much less than 60,000 gallons in London alone. To fit it for transit it is reduced by compression. Fifteen gallons may thus be diminished in volume until it fills an iron bottle holding a quart. Five or six gallons of the gas are, on an average, required for each patient. In the preparation of nitrous oxide for surgical purposes Dr Evans advises it to be made at least 24 hours before it is used, and further recommends its being thoroughly washed. An apparatus for the preparation of the gas was devised by Mr Porter, a description of which will be found in the ‘Transactions of the Odontological Society of Great Britain’ for 1868, in which also mention is made of a face-piece for its administration, the invention of Mr Clover. By means of this latter instrument the desiderata that the nitrous oxide should be inhaled without admixture with atmospheric air, and contamination arising from the expired air given off by the patient, are accomplished, for it has been found that when excitement and talking attend the inhalation of the gas, these effects are due to the presence of the carbonic acid thrown off by the lungs.

When inhaled in the ordinary way, nitrous oxide gas induces exhilaration and narcotism, without asphyxia. When, however, the atmospheric air is carefully excluded, it produces, as we have just seen, anæsthesia without exhilaration. The time required to produce anæsthesia varies from 25 to 120 seconds, by from 10 to 60 inhalations. A patient has been subjected for 10 minutes to its action without experiencing any unpleasant symptoms or after effects. Mr Randle says it is perfectly safe in all short operations, and possibly in long ones also, provided there is due admission of air at proper intervals. It seems tolerably certain that nitrous oxide is largely absorbed by the blood-corpuscles, and it is probable that its presence in them may temporarily act to the exclusion of oxygen, and thus prevent for a time that combination of oxygen with hæmoglobin upon which the red colour of the corpuscles depends. Chemistry, however, has failed to show that nitrous oxide is decomposed in the blood, or that it exerts any of the chemical properties of oxygen on the constituent elements of the blood. Whenever the slightest anæsthetic effect is communicated to the nervous system, a simultaneous effect is produced upon the medulla oblongata, the spinal chord, as well as upon the cerebrum and cerebellum.

The whole available force in the body is undoubtedly due to oxidation. This oxidation is accomplished by means of the blood, and it is therefore evident that a continuous flow of oxygenated blood to the nerve centres is necessary as a source of power and of sensibility, as well as for the reintegration of nerve tissue. Any deficiency of oxygen in the blood is followed by a decreased arterialisation of the whole volume of the blood. Under these conditions the exhalation of carbonic acid is relatively less rapid than its formation, and life cannot continue if the blood in the arteries becomes thoroughly venous, as well in colour as in character. That nitrous oxide, when inhaled, changes the colour of the blood-corpuscles is evidenced by the livid appearance of the face and mucous surfaces; the latter, indeed, is a characteristic accompaniment of its administration, and the darkened colour of the blood may be observed as it flows from the severed vessels. This colour of the blood is probably in part due to uneliminated carbonic acid; but that nitrous oxide possesses in a high degree the property of darkening the blood-corpuscles may be easily demonstrated by directing a jet of the gas for a few seconds upon a little arterial blood in a test tube. Yet, from what has previously been advanced on this point, this latter result may more strictly be due to physical than to chemical causes. An interruption of the circulation in any part of the organism is soon followed by local insensibility in the tissues from which the blood supply may have been withdrawn; and it is beyond dispute that, during the anæsthetic state, the circulation of the blood through the capillary system becomes diminished in velocity. A tendency to stasis begins to appear, accompanied at the same time by a considerable reduction in the supply of arterial blood. These are facts that admit of experimental demonstration, as does also another fact, viz. that during the period of insensibility produced by the inhalation of nitrous oxide the143 brain itself is in a state of comparative anæmia. In short, it appears most probable that an arrest of the capillary circulation through the brain, to which several writers have attributed a potential influence as the cause of anæsthesia, is simply, so far as it may exist, a result of it.

The anæsthesia produced by the inhalation of nitrous oxide would, therefore, appear to be referable to an altered condition of the blood, whereby the molecular dynamic changes are interfered with, this interruption being probably due either to the retention of carbonic acid, or to the presence of nitrous oxide; or, as the result of both conditions, to the exclusion of oxygen.

For minor operations nitrous oxide possesses many advantages over other anæsthetics. The principal of these is its safety. In America, in 200,000 cases in which it had been administered, there was only one case of death. Furthermore its use is not contra-indicated in patients having any constitutional derangement, nor for women who are either pregnant or suckling.

The ‘British Medical Journal’ for June 13th, 1868, contains an account of some experiments performed by Dr Burdon Sanderson, at Middlesex Hospital, with nitrogen. It seems to have been longer in producing insensibility than nitrous oxide, but no lividity of countenance accompanied, nor sickness or headache followed, its administration.

ANALEP′TIC. Syn. Analep′ticus, L.; Analeptique, Fr. Restorative; that recruits the strength lost by sickness.

Analep′tics. Syn. Analep′tica, L.; Analeptiques, Fr. In pharmacology, &c., restorative medicines and agents.

ANAL′YSIS (-e-sĭs). [Eng. L., Gr.] Syn. Analyse, Fr.; Auslösung, Zerlegung, Ger. In a gen. sense, the resolution of anything, whether an object of the senses or of the intellect, into its elementary parts. In chemistry, the resolution or separation of a compound body into its constituent parts or elements, for the purpose of either determining their nature, or, when this is known, their relative proportions. It is divided into QUAL′ITATIVE ANALYSIS and QUAN′TITATIVE ANALYSIS; and these again into PROX′IMATE ANALYSIS and UL′TIMATE ANALYSIS. The first consists in finding the components of a compound, merely as respects their nature or names; the second, in finding not merely the component parts, but also the proportions of each of them; the third gives the results in the names of the proximate or immediate principles or compounds which, by their union, form the body under examination; whilst the fourth develops the chemical elements of which it is composed.[56] An analysis may also be made to determine whether a certain body is or is not contained in a compound (as lead in wine); or it may be undertaken to ascertain all the constituents present; the extent of an investigation being merely limited by the object in view.

For success in chemical analysis a thorough acquaintance with the various properties of bodies is required, as well as aptitude in applying this knowledge in discriminating them, and separating them from each other. Judgment and expertness in manipulation are, indeed, essential qualifications. The method pursued must likewise be such as to attain the object in view with unerring certainty, and in the most expeditious manner. “The mere knowledge of the reagents, and of the reactions of other bodies with them, will not suffice for the attainment of this end. This requires the additional knowledge of a systematic and progressive course of analysis, or, in other words, the knowledge of the order, and succession, in which solvents, together with general and special reagents, ought to be applied, both to effect the speedy and safe detection of every individual component of a compound or mixture, and to prove with certainty the absence of all other substances. If we do not possess this systematic knowledge, or if in the hope of attaining an object more rapidly, we adhere to no method in our investigations and experiments, analysing becomes (at least in the hands of a novice) mere guesswork, and the results obtained are no longer the fruits of scientific calculation, but mere matters of accident, which sometimes may prove lucky hits, and at others total failures.” (Fresenius.)

ANALYSIS, SPECTRUM. More than half a century ago Sir John Herschel employed the prism in the analysis of coloured flames, and in 1834 Fox Talbot, by means of the same instrument, distinguished the difference between the spectra given by strontium and lithium, notwithstanding the similarity of the two in colour. But it was reserved for Messrs Kirchkoff and Bunsen, as the inventors of the spectroscope, to devise the only efficient method of analysing flame, and, at the same time, to furnish chemists with a means whereby they may detect with unerring certainty the presence of any known element by observing the spectrum it gives when such element is submitted to a temperature sufficiently high for it to emit a luminous vapour. That certain chemical substances when heated in the flame of the spirit-lamp or the blow-pipe, or any other source of comparatively white light, imparted characteristic colours to the flame, was a fact that had long been known to chemists; for example, when a salt of sodium was so treated, an intense yellow colour was imparted to the flame. A salt of potassium produced under144 the same circumstances a violet, strontium, a crimson colour, &c. These results could only be produced when the substance under examination contained but one of the salts in question. If more than one were present, this method of qualitative analysis was comparatively, if not wholly, valueless, because the specific colour communicated to the flame by the presence of one element would be masked, and, consequently, destroyed by the colour developed by the vapour of another or other elements. For instance, so much more vivid is the yellow colour given to flame by sodium salts than the violet tint imparted by those of potassium, that a very small trace of sodium prevents the unaided eye from perceiving the violet, even when the potassium compound is present in large quantity.

Very different optical effects, however, follow if the rays from the various-coloured flames are made to pass through a prism. As is well known, if a ray of ordinary white light is made to traverse a prism, when it issues from the prism it has become decomposed or dissected into seven luminous rays of as many different colours, the coloured image thus produced being called a prismatic spectrum, or simply a spectrum.

This phenomenon is owing to the prism refracting or bending out of its course the beam of light sent through it, and to each coloured ray of which the beam is made up being differently refracted.

“If, however, instead of the white flame coloured flames are examined by means of a prism, the light being allowed to fall through a narrow slit upon the prism, it is at once seen that the light thus refracted differs essentially from white light, inasmuch as it consists of only a particular set of rays, each flame giving a spectrum containing a few bright bands. Thus, the spectrum of the yellow soda flame contains only one fine bright yellow line, whilst the purple potash flame exhibits a spectrum in which there are two bright lines, one lying at the extreme red, and the other at the extreme violet end. These peculiar lines are always produced by the same chemical element, and by no other known substance; and the position of these lines always remains unaltered. When the spectrum of a flame tinted by a mixture of sodium and potassium salts is examined, the yellow ray of sodium is found to be confined to its own position, whilst the potassium red and purple lines are as plainly seen as they would have been had no sodium been present.”[57]

Equally characteristic and well-defined spectra, the bands in which have each an invariable and fixed position in the spectrum, are also produced when the coloured flames arising from heating to the requisite point the remaining salts of the alkalies and alkaline earths are examined by the prism. On the opposite page the first spectrum shows some of the fixed dark lines that are always observed when a solar beam is examined by the spectroscope. These lines are compared with the position of some of the more important bright lines furnished by the spectra of the metals of the alkalies and alkaline earths, when their chlorides are heated upon a loop of platinum wire introduced into the flame of a Bunsen gas-burner. The characteristic bright lines given by each metal are denoted by the letters of the Greek alphabet, the earliest letter indicating the most strongly marked lines.

In the potassium spectrum the most characteristic bright lines are the red line K α, and violet line K β. In the case of sodium nearly the whole of the light is concentrated on the intense yellow double line Na α. In the lithium spectrum a crimson band, Li α, is the prominent line; Li β is seldom visible, but at the elevated temperature of the voltaic arc an additional blue line becomes very intense. In the spectrum of cæsium two lines in the blue, Cs α and Cs β, are strongly marked. In rubidium the lines Rb α and Rb β in the blue, and Rb γ in the red are almost equally specific. Thallium is recognised by the intense green line Il α. The spectra of the metals of the alkaline earths are equally definite, though more complicated.

By means of the spectroscope quantities so inconceivably minute as the 33,000th of a grain of chloride of rubidium, the 170,000th of a grain of chloride of cæsium, the 2,500,000th of a grain of sodium, and the 6,000,000th of a grain of lithium, have been detected, and have revealed themselves to the sight by their characteristic bands in the spectrum. Hence it is that in making use of this branch of analysis the chemist has been enabled to show the universality of many elements hitherto regarded as being very sparingly distributed throughout the globe.

Thus lithium, which until lately was supposed to be one of the rare elements, has been found as a constituent of tea, tobacco, milk, blood, and in almost all spring waters. Furthermore, the prodigiously sensitive reactions afforded by the spectroscope have not only revealed the presence of infinitesimal quantities of known elements, but have led to the discovery of new ones which had escaped detection by the older and less delicate processes of analysis. It was by means of spectrum analysis that the two alkali metals, cæsium and rubidium, were discovered by Bunsen and Kirchkoff in 1860 in a mineral water at Durkheim, and that Mr Crookes in 1861 discovered the metal thallium in the deposit found in the flue of a pyrites furnace; whilst still more recently Messrs Reich and Richter, in a spectrum examination of a zinc ore from Freiberg, discovered the metal indium.

The most brilliant spectra are given by those salts which are the most easily volatilised, such as the chlorides, iodides, and bromides146 of the different metals. But it is only the metals of the alkalies and alkaline earths that give spectra that are characteristic. When it is desired to obtain the spectra of the other metals, they may be raised to the requisite temperature by means of the electric spark, which in passing through the two points of the metal operated upon volatilises a minute quantity of it, and thus enables it to emit its particular light. The electric sparks are best obtained by means of Ruhmkorff’s coil. Thus each metal may be made to yield a spectrum which specially belongs to it, and to it alone. When the electric discharge is sent through a compound gas or vapour, owing to the intense temperature generated separation of its constituents must take place, since the spectra produced are those of the elementary components of the gas. The permanent gases give each their peculiar spectrum when they are strongly heated, by which they may be recognised; thus the spectrum of hydrogen is composed of three bands, one being bright red, one green, and the other blue. Nitrogen gives a very complicated spectrum.

The accompanying figure exhibits a very complete form of the spectroscope adapted to a single prism.

P represents a flint-glass prism supported on the cast-iron tripod F, and retained in its place by the spring c. At the end of the tube A nearest the prism is a lens, placed at the distance of its focus for parallel rays from a vertical slit at the other end of the tube. The width of the slit can be regulated by means of the screw e. One half of this slit is covered by a small rectangular prism designed to reflect the rays proceeding from the source of light D, down the axis of the tube, whilst the rays from the source of light E pass directly down the tube. By this arrangement the observer stationed at the end of the telescope B is able to compare the spectra of both lights, which are seen one above the other, and he can at once decide whether their lines coincide or differ. a and b are screws for adjusting the axis of the telescope so as to bring any part of the slit at e into the centre of the field of vision.

The telescope as well as the tube C is moveable in a horizontal plane around the axis of the tripod. The tube C contains a lens at the end next to the prism, and at the other end is a scale formed by transparent lines on an opaque ground; it is provided with a levelling screw, d. When the telescope has been properly adjusted to the examination of the spectrum, the tube C is moved until it is placed at such an angle with the telescope and the face of the prism, that when a light is transmitted through the scale the image of this scale is reflected into the telescope from the face of the prism nearest the observer. This image is rendered perfectly distinct by pushing in the tube which holds the scale nearer to the lens in C, or withdrawing it to a greater distance, as may be required. The reflected lines of the scale can then be employed for reading off the position of the dark or bright lines of the spectrum, as both will appear simultaneously overlapping each other in the field of the telescope.

By turning the tube C round upon the axis of the tripod any particular line of the scale can be brought to coincidence with any desired line of the spectrum. Stray light is excluded by covering the stand, the prism, and the ends of the tube adjoining it with a loose black cloth. The dispersive power upon the spectrum may be much increased by using several prisms instead of one. Kirchkoff used four prisms in his experiments upon the solar spectrum. Great care must be observed in placing the prisms; the refracting edge of each prism must be exactly vertical, and the position of minimum deviation for the rays to be observed must be obtained.

The preceding remarks have reference to the spectra produced when the vapours of certain elements are evolved in flame derived from artificial sources. When, however, solar light is examined by the spectroscope, results entirely the reverse follow.

If a beam of sunlight be sent through the slit of the spectroscope, the prismatic image is seen to be intersected by a number of fine black lines, varying in thickness and intensity, and invariably occupying the same relative position in the solar spectrum. These lines were first noticed so far back as 1815 by a German optician, Frauenhofer, after whom they were named Frauenhofer’s lines; but it was not until the invention of the spectroscope that the origin of these lines could be accounted for. By so arranging the instrument as to cause the spectrum from a solar beam, and that from a metallic element, to fall upon the field of the telescope, so that the solar spectrum shall be above the other, both being perfectly parallel; the bright bands or lines of the metal are all seen to be continued in the dark solar lines, for, as may be seen by consulting the plate of the different spectra, several lines are sometimes produced by one element alone. If, for instance, the sodium and solar spectra are thus compared, the bright yellow sodium line will be found to147 agree exactly not only in position, but also in intensity and breadth, with one of the dark solar ones. And the same thing occurs when the comparison is made with many of the other metals, the bright lines in the respective spectra furnished by them are each coincident with a particular dark line in the solar spectrum, and from every dark line in the latter a corresponding bright one can be found amongst the spectra of the metals. From what has just been stated, the inference seems irresistible that this coincidence between the dark solar lines and the bright lines of the metals cannot be accidental, but must be due to some intimate connection between them, and that this is the case can be proved beyond refutation by a simple experiment, in which the bright metallic lines can be changed into dark ones, corresponding in every particular with those of the solar spectrum. Thus the bright yellow soda lines coincident with Frauenhofer’s lines can be converted into dark ones by allowing the rays from a strong source of white light to pass through a flame coloured with sodium, and then making them fall upon the slit of the spectroscope. If we examine the spectrum obtained by this means, instead of seeing the usual bright double band upon a black ground, there will be presented to our sight a double dark line, corresponding exactly with the position and width of the sodium line, and instead of the black ground there will be a continuous spectrum of white light, as in the solar spectrum.

The explanation of this remarkable phenomenon is due to Kirchkoff, and is as follows:—When any substance is heated sufficiently to render it luminous, rays of a certain and definite degree of refrangibility are given out by it; whilst the same substance has also the power of absorbing rays of this identical refrangibility. In the above experiment, therefore, the yellow flame absorbed the same kind of light as it gave out, a corresponding decrease of intensity in its own particular position in the spectrum occurred, and a dark line showed itself in consequence.

In the same manner and under similar conditions the spectra of many other substances have been reversed.

Reasoning on these facts, Kirchkoff has been able to account for the presence in the solar spectrum of Frauenhofer’s dark lines. He supposes that in the luminous atmosphere surrounding the sun the vapours of various metals are present, each of which would give its characteristic system of bright lines; but behind this incandescent atmosphere containing metallic vapour is the still more intensely heated solid or liquid nucleus of the sun, which emits a brilliant continuous spectrum, containing rays of all degrees of refrangibility.

When the light of this intensely heated nucleus is transmitted through the incandescent photosphere of the sun, the bright lines which would be produced by the photosphere are reversed, and Frauenhofer’s dark lines are only the reversed bright lines which would be visible if the intensely heated nucleus were no longer there.

The correctness of this theory has been rigorously tested by Kirchkoff himself, who submitted the solar spectrum to a most minute and searching examination.

As a result of the knowledge thus obtained, the presence of certain metals in the sun’s atmosphere was an inevitable deduction. The metals hitherto detected in the solar photosphere are—iron, sodium, magnesium, calcium, chromium, nickel, barium, copper, zinc, strontium, cadmium, cobalt, manganese, aluminium, and titanium. Hydrogen also exists in large quantity as an incandescent gas, and gives rise to the red protuberances that may be observed during a total eclipse.

During the total eclipse of 1869, M. Janssen, a French astronomer, was enabled to obtain and figure the specimen of these red protuberances, which, taken exclusively from that source of light, gave not dark lines, but bright ones, corresponding in position with those of hydrogen, magnesium, and sodium.

The fixed stars, unlike the moon and planets, which shine only by reflected light, are not merely illuminated by self luminous bodies, and yield spectra, which show them to contain many elements known to us; their spectra are crossed by dark lines similar to, but not identical with those given by the sun’s light. The spectrum yielded by the star Aldebaran shows it to contain hydrogen, sodium, magnesium, calcium, iron, tellurium, antimony, bismuth, and mercury; in the spectrum of Sirius only sodium, magnesium, and hydrogen have been found; whilst in that of Orionis there is an absence of hydrogen. Most of the nebulæ and comets give spectra in which there are only bright lines. It is hence inferred that these celestial bodies are composed of masses of glowing gas, and, unlike the sun and stars, do not consist of a solid or liquid mass surrounded by a gaseous atmosphere. In the nebulæ hydrogen and nitrogen only have been found; and in comets, principally carbon.

ANANAS HEMP (Ananassa sativa, S. Brumelia ananas, as well as other species). This hemp comes from the West Indies and Central and South America, where the common ananas is cultivated. It is rather inferior to some varieties for spinning.

ANATHERIN BALSAM. The following formula is published by the Netherlands Society:—Tincture of myrrh, 160 grms.; tincture of catechu, 80 grms.; tincture of guaiacum, 40 grms.; tincture of rhatany, 40 grms.; tincture of cloves, 30 grms.; spirit of cochlearia, 20 grms.; oil of cassia, 20 drops; otto of roses, 1 drop; proof spirit, 630 grms.148

ANATHERIN BALSAM (J. G. Popp, Vienna). A mouth-wash. Red sandal wood, 20 parts; guaiacum wood, 10 parts; myrrh, 25 parts; cloves, 15 parts; cinnamon, 5 parts; oils of cloves and cinnamon, of each, ²⁄₃ part; spirit, 90 per cent., 1450 parts; rose water, 725 parts. Digest and filter.

Dr Hager, who gives the above, says that on the expiration of the patent the following formula was published, but that a preparation made from that process had only a distant resemblance to the actual compound. Myrrh, 1 part; guaiacum wood, 4 parts; saltpetre, 1 part; to be macerated for a night with corn brandy, 120 parts; spirit of cochlearia, 180 parts. Then distil of this 240 parts, in which are to be digested for 14 days garden rue, cochlearia, rose leaves, black mustard, horseradish, pellitory root, cinchona bark, club-moss, sage-vetiver, and alkanet root, of each 1 part. Strain and filter, and to each 120 parts of the filtrate add 1 part of spirit of nitrous ether. (Hager.)

ANATOM′ICAL. Syn. Anatom′icus, L.; Anatomique, Fr.; Anatomisch, Ger. Belonging to anatomy or dissection.

Anatomical Prepara′tions. Objects of interest in both surgical and pathological anatomy, and specimens in natural history, preserved by subjecting them to antiseptic processes, to which is also frequently added injection with coloured fluids (which subsequently harden), amalgams, or fusible metal, in order to display more fully the minute vessels, or the microscopic anatomy of the several parts. See Fusible Alloy, Injections, Preparations, Putrefaction, Skeletons, Solutions, &c.

ANCH′OVY (-chō′-). Syn. Anchois, Fr.; Anchove, Anschove, Ger.; Acciughe, Anchiove. It.; Anchova, Port., Sp. The clu′pea encrasic′olus (Linn.), a small fish of the herring tribe, closely resembling the English sprat. It is common in the Mediterranean, and occurs in the greatest abundance and of the finest quality about the island of Gorgona, near Leghorn. It is taken in the night, during May, June, and July.

Anchovies are prepared for sale or exportation by salting or pickling them—the heads, intestines and pectoral fins having been first removed, but not the scales, and afterwards packing them, along with rock-salt, in the small kegs in which they are imported into this country. The small fish are valued more than the larger ones. For the table they are often fried to a pale amber colour, in oil or butter; having previously been scraped clean, soaked for an hour or two in water, wiped dry, opened (without dividing the fish), and had the back-bones removed. Before being put into the pan they are usually highly seasoned with cayenne; and after being again closed, are dipped into a rich light batter. They are also divided into fillets, and served as sandwiches, or in curried toasts. Anchovies are also extensively potted (POTTED ANCHOVIES), and made into butter (A.-BUTTER), and into sauce (A.-SAUCE), particularly the last.

The anchovy has a fine and peculiar flavour, and is eaten as a delicacy all over Europe. It was known to the Greeks and Romans, who prepared from it a kind of garum for the table. It is said to be aperitive, stimulant, and stomachic.

The high price of genuine Gorgona anchovies has led the fraudulent dealer to either substitute for them, or mix with them, fish of a less expensive kind. The most frequent SUBSTITUTIONS are Dutch, French, and Sicilian fish of allied species or varieties, sardines and even the common sprat. The genuine Gorgona fish is about the length of one’s finger; and may be known by its silvery appearance; by the greater thickness of its head, which is sharp-pointed, with the upper jaw considerably the longest, and the mouth deeply divided; the dusky brown colour of its back,[58] and the pink salmon colour of its flesh. When only 3 months old, its flesh is pale; when of 6 months, rather pink; when of 10 to 12 months (or in its prime), a beautiful deep pink colour; and when much older, darker, but less lively. The fin-rays, varying in number with the age of the fish, are—

	Yarrell.	Hassall.[59]
Dorsal	14,	16 (?).
Pectoral	15,	—
Ventral	7,	—
Anal	18,	19 (?).
Caudal	19,	26 (?).

These fins are delicate in structure and greenish-white; and the membranes connecting the rays almost transparent. “The length of the head, compared with the length of the body alone, is as 1 to 3; the depth of the body but 2-3rds of the length of the head, and compared to the length of the whole fish is as 1 to 7;” the tail is deeply forked, the gill covers are elongated, and the scales of the body large and deciduous.” “The breadth of the eye is 1-5th of the length of the whole head.”[60] Dutch fish may be generally known by being deprived of the scales, and the French fish by their larger size; and both by the paler or whiter colour of their flesh; and sardines and sprats by the flesh being white. The genuine fish may also be known by the pickle, after repose or filtration, being of a clear pinkish colour, without any red sediment; whilst that from spurious kinds is turbid and red only when agitated, and deposits a heavy red sediment (Armenian bole, Venetian red, or red ochre) on repose. See Butter, Potting, Powders, Sauces, &c.

ANCHU′SINE. (-kū′zĭn). [Eng., Fr.] Syn. Anchu′sic acid*, Pseu′do-alkann′ine*, Pseudo-alka′′nium*; Anchusi′na, L. The resinoid constituting the colouring matter of alkanet-root (which see).

ANCHYLO′SIS (ăngk-e-). [L.; prim. Gr.] Syn. Ankylo′sis, Ancylo′sis (ăn-se-), L.; Ankylose, Fr., Ger. In pathology, stiffness or immobility of a joint naturally moveable. Anchylosis is either true or complete, as when the extremities of the bones forming a joint are reunited and immovable; or false, or incomplete, where the affection depends upon a contraction of the tendons and ligaments surrounding the joints, which nevertheless admit of a small degree of motion. For the first there is no available remedy; for the second gentle and progressive flexion and extension of the part daily (carefully avoiding violence), friction with oleaginous and stimulating liniments, and the use of the hot bath, vapour bath, or hot-air or Turkish bath, and electricity, have been strongly recommended, and have frequently proved successful.

ANDITROPFEN (Kirchner and Menge Arolsen), for weak digestion. Senna, 20 parts; rhubarb, 3 parts; jalap, 6 parts; zedoary root, 2 parts; ginger, 2 parts; galangal, 3 parts; soda, bicarbonate, 5 parts; sugar, 15 parts; water, 300 parts; spirit, 65 parts. After digestion this is to be strained and mixed with an infusion of 30 parts of yarrow (with the flowers) in 300 parts of hot water. After standing some time filter. (Hager.)

ANDROGRAPHIS PANICULATA. (Ind. Ph.) Syn. Kariyát. Habitat. Commonly in shady places all over India.—Officinal part. The dried stalks and root (Andrographis Caules et Radix, Kariyat, Creyat). The stem, which is usually met with, with the root attached, occurs in pieces of about a foot or more in length, quadrangular, of a lightish-brown colour, and persistent bitter taste.—Properties. Bitter tonic and stomachic, very analogous to quassia in its action.—Therapeutic uses. In general debility, in convalescence after fevers, and in the advanced stages of dysentery.

Compound Infusion of Kariyát (Infusum Andrographis compositum). Take of Kariyát, bruised, ¹⁄₂ an ounce; orange-peel and coriander fruit, bruised, of each, 60 grains; boiling water, 10 fluid ounces. Infuse in a covered vessel for an hour and strain.—Dose. From 1¹⁄₂ to 2 fluid ounces, twice or thrice daily.

Compound Tincture of Kariyát (Tinctura Andrographis composita). Take of kariyát root, cut small, 6 ounces; myrrh and aloes, in coarse powder, of each 1 ounce; brandy, 2 pints. Macerate for seven days in a closed vessel, with occasional agitation; strain, press, filter, and add sufficient brandy to make two pints.—Dose. From 1 to 4 fluid drachms. Said to be tonic, stimulant, and gently aperient, and to prove valuable in several forms of dyspepsia, and in torpidity of the bowels.

ANDROPOGON (CYMBOPOGON) CITRATUM. Lemon Grass. (Ind. Ph.) Habitat. Commonly cultivated in gardens in India; also in Ceylon, upon a large scale, for the sake of its volatile oil.—Officinal part. The volatile oil (Oleum Andropogi Citrati, Lemon Grass Oil, Oil of Verbena), obtained by distillation from the fresh plant; of a pale sherry colour, transparent, extremely pungent taste, and a peculiar fragrant lemon-like odour.—Properties. Stimulant, carminative, antispasmodic, and diaphoretic; locally applied, rubefacient.—Therapeutic use. In flatulent and spasmodic affections of the bowels, and in gastric irritability. In cholera it proves serviceable by aiding the process of reaction. Externally, as an embrocation in chronic rheumatism, neuralgia, sprains, and other painful affections.

Dose. From 3 to 6 drops, on sugar or in emulsion. For external application it should be diluted with twice its bulk of soap liniment or any bland oil.

ANDROPOGON (CYMBOPOGON) NARDUS. Citronelle. (Ind. Ph.) Habitat. Madras Peninsula and Ceylon. The volatile oil of this plant has similar properties to A. citratum. and is used for the same purposes.

ANDROPOGON PACHNODES. (Ind. Ph.) The volatile oil of this plant possesses similar properties to that of A. citratum, and is used for the same purposes.

ANEMOM′ETER (ăn-e-). Syn. Anemom′etrum, L.; Anémomètre, Fr.; Windmesser, Ger. An instrument or apparatus for measuring the force or velocity of the wind, or of a current of air. Various contrivances have been adopted for this purpose. The anemometer of Dr Lind being also applicable to the determination of the draught of a chimney, and the strength of air-current, in ventilation, may be usefully described here:—

Uses and Appl. The open end (a) is kept, by means of a vane, presented to the wind, which acting on the surface of the water, or other liquid in b, raises the level of the fluid in the arm (c). The difference of the level of the fluid in the two arms of the instrument is the measure of the force of the wind. To estimate the draught of a flue or chimney, the arm (c) is placed in the chimney, and the orifice (a) in the apartment.[61]

ANEMOM′ETRY. Syn. Anemome′tria, L.; Anémometrie, Fr.; Windmessen, Ger. In meteorology, physics, &c., the art or act of measuring the velocity or force of the wind, or of ascertaining its direction.

ANEM′ONE (ă-nĕm′-o-ne). Syn. Anem′ony; Anem′one, L., Gr.; Anémone, Fr. The wind-flower. In botany, a genus of beautiful flowering herbaceous plants, of the nat. ord. Ranunculaceæ. The double flowers of some of the species are among the most elegant ornaments of our gardens. Others are used in medicine. They are all acrid and stimulating.

Anem′ones, Sea. (-o-nēz). Syn. An′imal-flowers‡, Sea sun′flowers‡. Animals of the genus actin′ia, so called from the resemblance of their claws or tentacles, when expanded, to the petals of a flower. They are of various colours, are generally fixed by one end to rocks or stones in the sand, and are very voracious, being accused of occasionally swallowing a mussel or a crab as large as a hen’s egg for a meal. They belong to the highly organised polypes of Cuvier.

ANEMONIN. A crystalline substance found in the leaves of several species of anemone, viz. A. pulsatilla, A. pretensis, A. nemorosa. Water distilled from these leaves, after some weeks, deposits a colourless inodorous substance, which softens at 150° C, giving off water and acrid vapours. It is purified by repeated crystallisation from boiling alcohol. Anemonin is a poisonous body. It causes slight irritation when applied to the skin. By the action of alkalies anemonin is transferred into anemonic acid.

ANEM′OSCOPE (ăn′-e—Brande, Mayne). Syn. Anemosco′pium, L.; Anémoscope, Fr.; Anemoskop, Ger. An instrument to measure the force and velocity of the wind. See Anemometer.

AN′EROID (-royd)[62]. In physics, &c., not fluid, or not depending on water or a fluid for its action; applied to a certain form of barometer (which see)

ANEURISM. A tumour on an artery, produced by the rupture of the inner coat of the vessel, and the blood getting between it and the outer coat.

ANGEL′ICA (-jĕl′-). [L., Port., Sp.; Ph. E. & D.] Syn. Garden Angelica; Angélique, Fr.; Angelika, A.-wurzel, Angelkraut, Ger. The angelica archangel′ica of Linnæus, an aromatic herbaceous plant with a biennial, fleshy root, indigenous to the north of Europe, but frequently found wild in England, and largely cultivated in our gardens. Dried root (ANGELICA, Ph. E.), aperient, carminative, diaphoretic, and tonic; much esteemed by the Laplanders, both as food and medicine;—fruit or seed (Angelica, Ph. D.) resembles the root, but is weaker. The whole plant has been extolled as an aromatic tonic. As a masticatory, it leaves an agreeable glowing heat in the mouth. The aromatic properties of this plant depend on a peculiar volatile oil and resin.

Uses, &c. It has been recommended in diarrhœa, dyspepsia, debility, and some fevers; but is now seldom used in medicine. Dose, 30 gr. to 1 dr. The dried root and seeds are used by rectifiers to flavour gin and liqueurs; and the fresh root, tender stems, stalks, &c., are made by the confectioners into an aromatic candy. See Candying, Liqueurs, &c.

Angelica Atropurpu′′rea. [Linn.] Syn. Amer′ican Angelica; Angelica, Ph. U. S. Hab. North America. Resembles garden angelica, but placed by some botanists in a separate, though allied genus. It is a popular remedy for flatulent colic, indigestion, and cardialgia, in the United States; and is there regarded as tonic, cordial, and aphrodisiac.

ANGEL′IC ACID. HC₅H₇O₂. A volatile substance, noticed by L. A. Buchner, jun., in angelica-root. It has a pungent sour smell, and a biting acid taste; is sometimes fluid and oleaginous, and sometimes crystallised in striated prisms.[63]

ANGO′LA Syn. Ango′la-wool, Ango′′ra-w., Ango′na-w., &c.; Poil de chevron d′Angora, Fr.; (Engoor′, Engour′, or Engu′ri) Tiftic, Tur. The wool of ‘ca′pra Angoren′sis’ or the Angora-goat, of which the shawls of Cashmere are made, and others in imitation of them. It is also used to make plush, light cloths for paletôts which are repellent of wet, &c.; and is extensively employed in France in the manufacture of lace more brilliant than that of Valenciennes and Chantilly, and at half the price. See Alpaca, Shawls, Wool, &c.

ANHYDRIDE. Most, if not all modern chemists, adopting Gerhardt’s practice of limiting the title of acid to a particular class of substances which contain hydrogen, now regard all true acids as salts of hydrogen. Formerly many bodies, such as silica or white arsenic, were looked upon as acids, though if we adopt the foregoing definition they are not really so until they have combined with water. Such bodies, because they contain no hydrogen, are now distinguished as anhydrides; the substances,151 for example, familiarly known as carbonic, sulphurous, and phosphoric acids, must, upon the above principle, be designated carbonic, sulphurous, and phosphoric anhydrides. We may also define an anhydride to be an oxide which forms an acid on treatment with water.

ANHY′DROUS (-drŭs; an′hydrous, as marked by Brande, is less usual). Syn. An′hydrus, L.; Anhydré, Fr.; Wasserfrei, Ger. Free from water; dry. In chemistry and mineralogy, a term frequently applied to substances, as acids, alcohol, gases, salts, minerals, &c., which do not contain either free or combined water. Gases may generally be rendered anhydrous by passing them through a tube containing fused chloride of calcium, or (e.g. AMMONIA and two or three others) quick-lime, in coarse powder; and some of them, by passing them through concentrated sulphuric acid. Salts may generally be dried by cautiously submitting them to the action of heat, or by exposure to a very dry atmosphere; and alcohol, and many other volatile fluids, by careful distillation from chloride of calcium, or some other highly hygrometric substance.

AN′IL. [Fr., Sp., L.] The indigof′era anil of botanists—one of the plants yielding ‘indigo’—a native of America, but now largely cultivated in the East Indies. See Indigo (and below).

AN′ILINE[64] (-een). [Eng., Fr.] C₆H₇N. Syn. Phenyl′amine; Anili′na, Anili′num, &c., L. A peculiar volatile organic base first noticed by Unverdorben in empyreumatic bone-oil, and afterwards obtained by Runge from coal-tar, and by Fritzsche, Zinin, A. W. Hofmann, and others, as a product of various reactions, processes, and decompositions, particularly those attending the destructive distillation of organic bodies.

Prep. Aniline is now almost invariably obtained, on the large scale, either directly or indirectly from coal-tar or indigo; and chiefly from the basic oil or naphtha, or the nitrobenzol, of which the former is the principal source. The following are the leading commercial and experimental processes:

1. From COAL-TAR or COAL-TAR NAPHTHA:—The basic oil or basic portion of coal-tar or coal-tar naphtha, forming the latter, denser, and least volatile products of the distillation or rectification of these substances, is strongly agitated, for some time, along with hydrochloric acid in slight excess, a glass globe, or, on the large scale, a suitable vessel of lead, or of enamelled iron, being employed for the purpose; the clear portion of the liquid (containing the hydrochlorates of the bases present) is then decanted and carefully evaporated over an open fire until acrid fumes begin to be disengaged, when it is again decanted or filtered; the clear liquor, or filtrate is next treated with potash or milk of lime in excess, by which the bases—chiefly aniline and chinoline—are liberated under the form of a brownish oil; the whole of the resulting mixture is now submitted to distillation, the portion which passes over at or about 360° Fahr., and which consists chiefly of crude aniline, being collected separately; the product is purified by rectification and recollection, once or oftener, at the same temperature, and, lastly, by fresh treatment with hydrochloric acid and careful distillation with excess of potash, or milk of lime, as before.

2. From NITROBENZOL:—a. (Zinin.) An alcoholic solution of nitrobenzol, after saturation with ammonia, is treated with sulphuretted hydrogen, until, after some hours, a precipitation of sulphur takes place; the brown liquid is then repeatedly saturated with fresh sulphuretted hydrogen, until no more sulphur separates, the reaction being aided by occasionally heating or distilling the mixture; an excess of acid is next added, and, after filtering the liquid, and the removal of the alcohol and unaltered nitrobenzol by ebullition or distillation, the residuum is lastly distilled with caustic potash, in excess. The ANILINE found in the receiver may be rendered quite pure by forming it into oxalate of aniline, repeatedly crystallising the salt from alcohol, and finally distilling it with excess of caustic potassa, as before.

The following is a cheaper and more convenient process; and probably the best, or one of the best, that has yet been invented for obtaining aniline:—

b. (M. Béchamps.) From nitrobenzol distilled along with basic protacetate of iron; or, what is better, by distilling a mixture of iron-filings, 2 parts, and acetic acid, 1 part, with about an equal volume of nitrobenzol, the reaction being assisted, whenever the effervescence flags, by the application of a gentle heat. The liquor found in the receiver consists of aniline and water, from which the first, forming the lower portion, is obtained, after sufficient repose in a separator; or more easily, by adding a very little ether, which by dissolving in the aniline, causes it to rise to the surface, when it is at once decanted. A very spacious glass or earthenware retort must be employed in the process, as the mass swells up violently; and it must be connected with the receiver, on the small scale, by means of a Liebig’s condenser, and, on the large scale, by an ordinary worm-pipe and tub, kept in good action by a sufficient flow of cold water.

The apparatus for carrying out Béchamp’s method was devised by Nicholson, and is exhibited in the subjoined plate.

“It consists essentially of a cast-iron cylinder (A) of 10 hectolitres (220 cubic gallons) capacity. A stout iron tube is fitted to this152 vessel, reaching nearly to the bottom of the cylinder. The upper part of this tube is connected with the machinery (G), while the surface of the tube is fitted with steel projections. The tube serves to admit steam, as well as acting as a stirring apparatus. Sometimes, instead of this tube, a solid iron axle is employed, and in this case there is a separate steampipe (D). Through the opening at K the materials for making aniline are put into the apparatus, while the volatile products are carried off through E. H serves for emptying and cleaning the apparatus. The S-shaped tube connected with the vessel B acts as a safety valve. When it is intended to work with this apparatus there is poured into it through K 10 parts of acetic acid at 8° B. (sp. gr. 1·060), previously diluted with six times its weight of water; next there are added 30 parts of iron filings, or cast-iron borings, and 125 parts of nitrobenzol, and immediately after the stirring apparatus is set in motion. The reaction ensues directly, and is attended by a considerable evolution of heat and vapours. Gradually more iron is added until the quantity amounts to 180 parts. The escaping vapours are condensed in F, and the liquid condensed in R is from time to time poured back into the cylinder A. The reduction is finished after a few hours.”

3. From INDIGO:—Powdered indigo is added to a boiling and highly concentrated solution of caustic potash, as long as it dissolves and hydrogen gas is liberated; the resulting brownish-red liquid is evaporated to dryness, and the residuum is submitted to destructive distillation in a retort, which, owing to the intumesence of the mass, should be strong and spacious. The ANILINE is found in the receiver under the form of a brownish oil mixed with ammoniacal liquor, and by separation from the latter, and subsequent rectification, is obtained nearly colourless. It may be further purified, as in the preceding processes.—Prod. 18 to 20% of the indigo employed.

4. By fusing, with proper precautions, a mixture of isatine and hydrate of potassium (both in powder); a retort connected with a well-cooled receiver, being employed as the apparatus. Said by Profs A. W. Hofmann and Muspratt to be “the most eligible process for isolating” aniline.[65]

5. From anthranilic acid mixed with powdered glass or sand, and rapidly heated in a retort.

6. By treating an alcoholic solution of benzine with a little zinc and hydrochloric acid.

In Zinin’s process the nitrobenzol is dissolved in alcohol, and the solution, after the addition of ammonia, is saturated with sulphuretted hydrogen. After standing some time the solution deposits a large quantity of sulphur, and the liquid yields aniline.

Many other reducing agents have been proposed for the conversion of nitrobenzol into aniline, such as arsenite of sodium, powdered zinc, &c., but on the large scale they have all been found inferior to the process of Béchamp. Kremer’s process consists in heating one part of nitrobenzol in a proper apparatus with five of water and two and a half of zinc dust. When the reaction is completed the aniline, amounting to about 65% of the weight of the benzol, is distilled off in a current of steam.

Prop., &c. A thin, oily, colourless liquid, with a faintly vinous odour, and a hot and aromatic taste; very volatile in the air; miscible in all proportions with alcohol and ether; very slightly soluble in water; neutral to ordinary test-paper, but exhibiting an alkaline reaction to dahlia-petal infusion and paper; dissolves camphor, sulphur, and phosphorus, and coagulates albumen; possesses a high refractive power; and precipitates the oxides of iron, zinc, and alumina, from solutions of their salts, and neutralises the acids, like ammonia. With the acids it forms numerous crystallisable compounds of great beauty, and which are easily formed, and are precisely analogous to the corresponding salts of ammonia. These, on exposure to the air, acquired a rose colour, in many cases gradually passing into brown. Its boiling-point is 359° to 360° Fahr.; sp. gr. 1·028.

Tests.—1. Chromic acid gives a deep greenish or bluish-black precipitate with aniline and its salts:—2. Hypochlorite of lime strikes an extremely beautiful violet colour, which is soon destroyed:—3. The addition of two or three drops of nitric acid to anhydrous aniline produces a fine blue colour, which, on the application of heat, passes into yellow, and a violent reaction ensues, sometimes followed by explosion:—4. With bichloride of platinum it yields a double salt (platino-chloride of aniline)153 analogous to the like salt of ammonia. These reactions distinguish it from all other substances.

Commercial aniline is a mixture consisting in great part of aniline, paratoluidine (solid), and orthotoluidine in variable proportions. In addition it contains small amounts of metatoluidine, nitrobenzol, odorine, &c., but for all practical purposes it may be regarded as a mixture of aniline and toluidine. These anilines are obtained from a portion of the light coal-tar naphtha boiling between certain temperatures, by treating it first with nitric acid to convert it into the nitro-compounds, and then reducing these with iron and acetic acid, as already described under Béchamp’s process. It is very plain that as the coal-tar naphtha contains variable proportions of benzol and toluidine, the resulting product must also vary in the quantities of aniline and toluidine it will contain. In order to distinguish between various samples of commercial aniline, Reimann submits them to fractional distillation and compares the results. He places 100 c. c. of the sample to be tested in a retort fitted with a thermometer and heated by means of an oil bath. The liquid as it distils is received in a narrow graduated cylinder, and the amount that passes over between every 5° C. (9° F.) is noted.

In order to obtain standards for comparison he first distilled a sample of light aniline, or kuphaniline, as he terms it, then one of heavy aniline or baraniline; afterwards mixtures of the two in varying proportions. In the accompanying table the results are given.

Centigrade	K.	100	90	85	80	75	60	50	25	0
	B.	0	10	15	20	25	40	50	75	100
Below 180°		8¹⁄₂	7	2¹⁄₂	5¹⁄₂	7	...	7	5¹⁄₂	...
180°—185°		54	50	29¹⁄₂	22	5¹⁄₂	7	4¹⁄₂	2¹⁄₂	2
185°—190°		34	34	56¹⁄₂	55¹⁄₂	55¹⁄₂	37	7¹⁄₂	4¹⁄₂	1¹⁄₂
190°—195°		...	5	7¹⁄₂	8¹⁄₂	15	33	42	17	8
195°—200°		...	...	...	...	9	...	19	36	18
200°—205°		...	...	...	...	4¹⁄₂	16	10	16	39
205°—210°		...	...	...	...	...	...	3¹⁄₂	8	19
210°—215°		...	...	...	...	...	...	...	4¹⁄₂	7
Residue		3¹⁄₂	4	4	8¹⁄₂	3¹⁄₂	7	6¹⁄₂	5	5¹⁄₂

To ascertain the quality of any sample it is only necessary to distil it in the manner already described, and compare the results with those in the above table.

(For further information consult Wagner’s ‘Chemical Technology,’ Calvert’s ‘Dyeing and Calico Printing,’ edited by Stenhouse and Groves; Crooke’s ‘Practical Handbook of Dyeing and Calico Printing,’ Ure’s Dictionary, edited by Hunt.)

Uses, &c. Chiefly in dyeing, for the production of colouring matter of various rich shades of purple and violet, some approaching pink, by the action of chromic acid; and of a splendid crimson, by the action of various oxidising agents. It forms the basis of the celebrated new dyes for silks lately patented by Mr W. H. Perkin, and others, and which are not only more delicate and gorgeous in tint, but also more permanent, than any produced by other substances.

Besides numerous salts, various substitution compounds of aniline have been formed, all of which possess vast scientific interest, and several are likely to prove of importance in the arts. See Dyeing, Indigo, Tar Colours, &c. (also below.)

Aniline, Chro′mates of. Prep. 1. (NEUTRAL CHROMATE.) From sulphate or oxalate of aniline and chromate of potash, by double decomposition.

2. (BICHRO′MATE:—Mr W. H. Perkin.) Sulphate of aniline and bichromate of potash, in equivalent quantities, are separately dissolved in water, and the solutions, after being mixed, are allowed to stand for several hours. The whole is then thrown upon a filter, and the black precipitate which forms is washed and dried. It is next digested in coal-tar naphtha (—? benzol), to extract a brown resinous substance; after which it is digested in alcohol, to dissolve out the colouring matter (BICHROMATE OF ANILINE), which is left behind on distilling off the spirit, as a coppery friable mass. Patented.

Aniline, Ox′alate of. (C₆H₇N)₂C₂O₄. Obtained by saturating an alcoholic solution of oxalic acid with aniline; the salt separating as a crystalline mass. It is very soluble in hot water; much less so in cold water; only slightly soluble in alcohol; and insoluble in ether. It may be crystallised from hot water or boiling alcohol. Used chiefly to form other salts.

Aniline, Sul′phate of. (C₆H₇N)₂SO₄. Prepared by saturating aniline with dilute sulphuric acid, and gently evaporating the liquid until the salt separates. By re-solution in boiling alcohol, it crystallises out, as the liquor cools, under the form of very beautiful colourless plates, of a silvery lustre. It is freely soluble in water, and in hot alcohol; scarcely soluble in cold alcohol; and insoluble in ether.154 It is chiefly employed in the preparation of the new aniline dyes.

ANIMAL′CULE (-kūle). [Eng., Fr.; pl. animal′cules.] Syn. Animal′culum (pl., animal′cula [66]), L.; Thierchen, Ger. In zoology and physiology, a microscopic animal, or one so extremely small, that it is either invisible, or not distinctly discernible, without the aid of a lens or microscope; more especially one that is not perceptible to the naked eye. “A mite was anciently thought the limit of littleness; but there are animals 27,000,000 of times smaller than a mite.” A thousand millions of some of the animalcula found in common water are said to be collectively of less bulk than a single grain of sand; yet their numbers are so prodigious as sometimes to give the fluid they inhabit a pale red or yellow tinge. The milt of a single codfish is said to contain more of these minute animals than there are people in the whole earth. Animalcula were first scientifically observed by Leuwenhoek about the year 1677. Assisted by the microscope he unveiled, as it were, he created a new world for future naturalists and microscopists to explore.

“Take any drop of water,” says Professor Rymer Jones, “from our rivers, from our lakes, or from the vast ocean itself, and place it under the microscope; you will find therein countless living beings moving therein in all directions with considerable swiftness, apparently gifted with sagacity, for they readily elude each other in the active dance they keep up.... Increase the power of your glasses, and you will soon perceive inhabiting the same drop, other animals compared to which the former were elephantine in their dimensions, equally vivacious and equally gifted. Exhaust the art of the optician, strain your eyes to the utmost, until the aching sense refuses to perceive the little quivering movement that indicates the presence of life, and you will find that you have not exhausted nature in the descending scale.”

Amongst the most remarkable discoveries of modern science must be reckoned that of fossil animalcules in such abundance as to form the principal part of extensive strata. This discovery is due to Ehrenberg, who found the Polierschiefer (the polishing slate or tripoli) of Bilin to be almost entirely made up of the siliceous shields of a minute fossil animalcule, the length of one of which is about ¹⁄₂₈₈th of a line, so that about 23,000,000 of animalcules must have gone to form a cubic line, and 41,000,000,000 to form a cubic inch of the rock. Ehrenberg succeeded in discovering the formation of similar strata in deposits of mud at the bottom of lakes and marshes, the mud swarming with living animalcules, probably in their turn to be fossilised. The bergmehl, or mountain meal of Sweden and other parts of Europe, which is sometimes used as an article of food, is entirely composed of the remains of animalcules; not merely, however, of their siliceous shields, for it contains a considerable per-centage of dry animal matter. Some animalcules prefer waters impregnated with iron, and their death gives rise to an ochreous substance in which iron is a principal ingredient.

AN′IME (ăn′-ĭm-e). [Eng., L., Sp.] Syn. Gum-an′ime, A.-res′in; Animé, Fr.; Animeharz, Kourbarillharz, Ger.; Courbaril, Jutaiba, Nat. A pale brownish-yellow, transparent, brittle resin, which exudes from the hymenæa courbaril (Linn.) or locust-tree, the h. martiana, and other species of hymenæa growing in tropical America. It contains about ·2% of volatile oil, which gives it an agreeable odour; melts without decomposition; is (nearly) insoluble in alcohol and in caoutchoucine, but forms a gelatinous mass in a mixture of the two. (Ure.) It burns readily, emitting a very fragrant smell. Sp. gr. 1·054 to 1·057.

Uses, &c. As a fumigation in spasmodic asthma; in solution as an embrocation; and in powder as a substitute for gum guaiacum. In this country it is chiefly employed to make varnishes and pastilles (which see).

AN′ION (-y′ŭn—Br., We.; ă-nī′-ŭn—Smart). Literally, ‘upward going,’ in electro-chemistry, a substance which is evolved from the surface where the electrical current is supposed to enter the electrolyte; an electro-negative body, or one which passes to the positive pole, or anode, in electrolysis, as opposed to a CATION. See Anode, Ions, &c.

AN′ISATED. Syn. Anisa′tus, L.; Anisé, Fr. In pharmacy, the art of the liqueuriste, confectioner, &c., applied to articles or preparations impregnated or flavoured with aniseed.

AN′ISE (-ĭs). Syn. Ani′sum, Pimpinel′la a. (Linn.), A. officina′le, L.; Anis, Fr.; Anis, Gemeiner Anis, Ger. An annual plant of the nat. ord. Umbelliferæ (DC.). Hab., Egypt, Scio, and the Levant; but largely cultivated in Malta, Spain, Germany, and various other parts of Asia and Europe. “A considerable quantity is cultivated at Mitcham, in Surrey, chiefly for the use of the rectifiers of British spirits.” (Stephenson.) Fruit, aniseed. (See below.)

AN′ISEED. Syn. An′ise, An′ise-seed; Sem′ina ani′si, Fruc′tus a., L.; Anis, A. vrai, Graines d’anis, Semence d’anis, Fr.; Anis, Anisamen, Ger.; Anis, Sp.; Anice, It. The aromatic fruit or seed of the pimpinella anisum just noticed.

Prop., Uses, &c. Its aromatic properties depend on the presence of volatile oil. The seed and oil, and a spirit and a water prepared from them, are officinal in the pharmacopœias. Both the seed and its preparations are reputed155 stimulant, stomachic, carminative, pectoral, diuretic, and emmenagogue. They are commonly used to relieve flatulence and colicky pains, and to prevent the griping effects of certain cathartics; and they have long been popular remedies for coughs, colds, and other breath ailments. They are esteemed especially useful in warming the stomach and expelling wind, particularly during infancy and childhood; the distilled or flavoured water being usually employed. Nurses also take the latter to promote the secretion of milk, to which it at length imparts its peculiar odour and flavour. In veterinary practice the powdered seed is used as a carminative, pectoral, and corroborant. The essential oil is said to be poisonous to pigeons. (Vogel; Hillefield.) Aniseed is principally used to flavour liqueurs, sweetmeats, and confectionery.—Dose (of the powder), 10 gr. to 1 or 2 dr.; for a horse, ¹⁄₂ to 1 oz.; cattle, ³⁄₄ to 2 oz.

Pur., &c. Powdered aniseed is nearly always adulterated, the adulterant being generally linseed meal. Sometimes, as for the horse, the latter is entirely substituted for it, a few drops of oil of aniseed being added to give it smell. The adulteration is not readily detected by the uninitiated, owing to the strong odour of aniseed; but readily by the microscope. The fruit of myrrhis odorata (sweet cicily), and of illicium anisatum (star-anise), also possess the odour and flavour of common aniseed; indeed, most of the essential oil now sold as ‘oil of aniseed’ is star-anise oil. See Liqueurs, Oils, Spirits, Waters, &c.

Anise, Star′. The fruit or seed of illi′′cium anisa′tum (Linn.), an evergreen tree growing in Japan and China. The odour and properties of both the seed and oil greatly resemble those of common anise. They are both employed by the liqueuriste. See Aniseed (above), &c.

ANISOCHILUS CARNOSUM. Nat. order Labiatæ. An Indian plant. It is stimulant, diaphoretic, and expectorant; is used in quinsy, and by the native doctors of Travancore in catarrhal affections. Dr Bidie, an Indian practitioner, characterises it as a mild stimulating expectorant, and as such particularly useful in the coughs of childhood. Its properties depend upon a volatile oil.

ANISOMELES MALABARICA. An Indian plant. Nat. order Labiatæ. Few plants are held in higher esteem, or more frequently employed in native practice in Southern India, than this. An infusion made of the leaves is very generally used in affections of the stomach and bowels, catarrhal complaints, and intermittent fevers.

Dr Wright says that in addition to its internal use in the case of fevers, patients are made to inhale the vapour of a hot infusion, so as to induce copious diaphoresis. An infusion of the leaves is reported to be powerfully diaphoretic, and to have been found very useful in the low continuous fevers of the natives. An oil obtained by distillation from the leaves is likewise stated to be an effectual external application in rheumatism.

ANNEAL′ING. Syn. Nealing†§; Le recuit, Fr.; Das anlassen, Ger. The art of tempering by heat: appropriately, the process by which glass, porcelain, &c., are rendered less frangible, and metals which have become brittle by fusion, or long-continued hammering, again rendered tough and malleable.

Glass vessels, and other articles of glass, are annealed by being placed in an oven or apartment near the furnaces at which they are formed, called the ‘leer,’ where they are allowed to cool very slowly, the process being prolonged in proportion to their bulk.

Steel, iron, and other metals are annealed by heating them and allowing them to cool slowly on the hearth of the furnace, or in any other suitable place, unexposed to the cold. Steel is also annealed by being made red-hot, and in that state is placed in a heap of dry saw-dust till cold, when it will be found quite soft.

Cast-iron is rendered tough and malleable, without ‘puddling,’ by embedding it in ground charcoal or hæmatite, and thus protected, keeping it exposed at a high temperature for several hours, after which the whole is allowed to cool very slowly.

Prince Rupert’s drop may be mentioned as an example of unannealed glass, and common cast-iron of unannealed metals, to which heads the reader is referred.

ANNOT′TA. Syn. Anot′to, Annat′to, Annat′ta; Arnat′to, Arnot′to, &c.; Orlea′na, Ter′ra o.*, &c., L.; Roucol, Rocou, Roucou, Fr.; Orleans, Ger. A colouring matter forming the outer pellicle of the seeds of the bix′a orella′na (Linn.), an exogenous evergreen tree, common in Cayenne and some other parts of tropical America, and now extensively cultivated in both the E. and W. Indies. It is usually obtained by macerating the crushed seeds or seed-pods in water for several weeks, ultimately allowing the pulp to subside, which is then boiled in coppers to a stiff paste, and dried in the shade. Sometimes a little oil is added in making it up into cakes or lumps. A better method is that proposed by Leblond, in which the crushed seeds are simply exhausted by washing them in water (—? alkalised), from which the colouring matter is then precipitated by means of vinegar or lemon-juice; the precipitate being subsequently collected, and either boiled up in the ordinary manner, or drained in bags and dried, as is practised with indigo. Annotta so prepared is said to be four times as valuable as made by the old process.

Prop. Good annotta is of a brilliant red colour; brighter in the middle than on the outside; feels soft and smooth to the touch;156 has a good consistence, and a strongly characteristic but not a putrid smell. It is scarcely soluble in water; freely soluble in alcohol, ether, oils, and fats, to each of which it imparts a beautiful orange colour, and in alkaline solutions which darken it; acids precipitate it of an orange red hue; strong sulphuric acid turns it blue. Its most important property is the affinity of its colouring matter for the fibres of silk, wool, and cotton.

Pur. Annotta is very frequently adulterated; indeed, nearly always so. To what extent the sophistication of annotta is carried may be judged from the statement of Mr Blyth, who says that on examination of thirty-four samples of various kinds, as imported and obtained from English makers and as purchased from dealers, he found only two that were genuine. As annotta is often used to give colour to different articles of diet, it is important that it should be as pure as possible; otherwise injurious effects detrimental to health may be caused by partaking of any food to which it is added. Now, amongst the list of adulterants given below are three, at least, unmistakeable poisons, viz. red lead, orange chrome, and sulphate of copper. It is but right to state of the first of these substances (red lead) that Mr Blyth says it is extremely doubtful whether it is now employed to the extent it formerly was. He also ascribes its presence in annotta to the impure Venetian red which is used, the employment of this colour being a necessity because of the large quantities of flour and lime which are mixed with the annotta, which thereby becomes so reduced in colour that it is essential to have recourse to salt, alkalies, and the red earths to restore it to its original standard. The adulterants are generally meal, flour, or farina, and often chalk or gypsum, with some pearlash and oil, or even soap, to give it an unctuous character; turmeric, Venetian red, red ochre, orange chrome, or even red lead, to give it ‘colour,’ and common salt, and sometimes even sulphate of copper, to prevent decomposition—the last two being poisonous. Sometimes a little carbonate of ammonia is also added to it to improve the colour. When quite pure it contains about 28% of resinous colouring matter, and 20% of colouring extractive matter (Dr John), and should leave only a small quantity of insoluble residuum after digestion in alcohol, whilst the ash resulting from its incineration should not exceed 1¹⁄₂ to 2%. The quantity, colour, &c., of the ash will give an easy clue to the inorganic adulterants, if any are present, which may be then followed up by a chemical examination. The presence of red lead may be detected by heating it on a piece of charcoal in the reducing flame of the blowpipe, by which a small bead of metallic lead will be obtained. If it contains chalk, ochre, gypsum, &c., the undissolved residuum of the washed ash gives the amount of the adulteration (nearly).

Microscopical Examination of Annotta.—When annotta is subjected to a microscopical examination the outer red portion will be found to present an almost homogeneous appearance, whilst the surface of the seed proper will be seen to consist of narrow or elongated cells or fibres disposed in a vertical direction, while the inner white portion will be seen to be made up of cells filled with starch corpuscles, well defined, of medium size, and resembling in the elongated and stellate hilum the starch granules of the pea and bean.

When the annotta is manufactured, and an unadulterated sample is examined, but little structure is met with. Portions of the outer cells may be seen; and in those samples which in the course of their preparation have not been subjected to the action of boiling water, a few starch granules may be observed.

Since annotta, when manufactured, presents so few evidences of structure, we are easily able, with the microscope at our command, to detect the presence of most foreign vegetable substances. These consist of turmeric powder, wheat, rye and barley starch, and sago flours. The salt and alkali present in the fraudulent annotta generally greatly alter the appearance of the turmeric. Most of the colouring matter of the cells is discharged, so that the starch corpuscles contained within them become visible. Loose starch granules of turmeric may also be frequently seen, and in a much enlarged condition, owing to the action of the alkali upon them.

The following process for conducting the assay of annotta is given by Mr Blyth:—

“In order to estimate the commercial value and detect adulteration in a sample, the quickest and best way is the following: Weigh accurately a gramme in a small platinum dish; dry in the water-bath for a couple of hours, then weigh; the loss is the water. Finely powder, and digest it for some hours in alcohol; then boil, filter and treat with successive portions of alcohol until all the colouring-matter is dissolved; filter, evaporate the filtrate down and weigh; the result is the resin. The insoluble portion will in a good commercial specimen consist of woody matter, extractive, gluten, &c. For the ash weigh another gramme in a platinum dish; dry for a short time over the water-bath; then powder and burn until it ceases to lose weight. It is prudent to fuse a little on charcoal with carbonate of soda before the blow-pipe before burning it in a platinum vessel, as there may be lead in the annotta. The ash should then be submitted to the various reagents in order to detect lime, alumina, &c. A correct determination of ash and resin is all that is required to definitely pronounce upon the purity or impurity of the samples.”

The sample was in the form of a paste, colour deep red, odour peculiar, but not disagreeable.157

Water	24·2
Resinous colouring matter	28·8
Ash	22·5
Starch and extractive matter	24·5
	———
	100·0

The following is an analysis of an adulterated specimen. The sample was in a hard cake of a brown colour, with the maker’s name stamped upon it, and marked “patent;” texture hard and leathery, odour disagreeable:

Water	13·4
Resin	11·0
Ash, consisting of iron, chalk, salt, alumina, silica	48·3
Extractive matter	27·3
	———
	100·0

Thus, in the one the resin was 28%, the ash 22; in the other the resin was only 11%, the ash no less than 48%.

Uses, &c. To colour varnishes and lacquers; as a pigment for painting velvet and transparencies; as a colouring matter for cheese (1 oz. to 1 cwt. of curd), for which purpose it is not injurious, if pure; and as a dye-stuff for cotton, silk, and wool, particularly the second, to which it imparts a beautiful orange-yellow hue, the shade of which may be varied from ‘aurora’ to deep orange by using different proportions of pearlash with the water it is dissolved in, and by applying different mordants before putting it into the dye-bath, or different rinsing liquids afterwards. The hues thus imparted are, however, all more or less fugitive.

Annotta Cake. Syn. Flag annotta; Orlea′na in fo′liis, L. From Cayenne; bright yellow, firm and soft to the touch; in square cakes, weighing 2 or 3 lbs. each.

Annotta Egg. Syn. Lump annotta; Orlea′na in o′vulis, L. Generally inferior.

Annotta, Eng′lish. Syn. Trade a., Reduced’ a.; Orlea′na reduc′ta, L. A fraudulent mess commonly prepared from egg or flag annotta, gum tragacanth, flour, or farina, chalk, soap, train-oil, Venetian red, or bole, common salt, water, mixed by heat in a copper pan, and formed into rolls. Sold for genuine annotta, from which it is readily distinguished by its inferior quality and its partial solubility in alcohol.

Annotta Roll. Syn. Orlea′na in rot′ulis, O. in bac′ulis, L. From the Brazils; hard, dry, brown outside, yellow within. When pure, this is the variety most esteemed, and the one preferred for colouring cheese.

Annotta, Solu′tion of. Syn. Essence of Annotta, Extract of a., Annotta-dye, &c.; Solu′tio orlea′næ, Extrac′tum o., &c., L. A strong aqueous solution of equal parts of annotta and pearlash, the whole being heated or boiled together until the ingredients are dissolved. Sold in bottles. See Annotta (above), Nankeen Dye, &c.

ANNUALS. Plants which bear flowers and fruit in the same year when raised from seed.

AN′O-. [Gr.] In composition, upwards, &c.; as in anocathar′tic (emetic).

AN′ODE. Literally, ‘upward way,’ in electro-chemistry, the ‘way in,’ or that by which the electric current is supposed to enter substances through which it passes, as opposed to the CATHODE, or that by which it goes out; the positive pole of a voltaic battery.

AN′ODYNE (-dīne). Syn. Ano′dynus (-dĭnŭs-), L.; Anodin, Fr.; Schmerzstillend, Ger. That allays pain; soothing; atalgic.

Anodynes. Syn. Ano′dyna (sing., ano′dy̆̆num), L.; Anodins, Remèdes a., Fr. In medicine and pharmacy, substances and agents which allay pain. Some (as the PAREGORICS) act by actually assuaging pain; others (HYPNOTICS) by inducing sleep; whilst a third class (NARCOTICS) give ease by stupefying the senses, or by lessening the susceptibility to pain. Among the principal anodynes are opium, morphia, henbane, camphor ether, chloroform, chloral hydrate, and other medicines of the like kind; to which must be added spirituous liquors, wines, and the stronger varieties of malt liquor. “The frequent use of anodynes begets the necessity of their continuance.” (W. Cooley.)

Anodyne, In′fantile (-īle). Syn. Ano′dynum infan′tile (-tĭl-e), L. Prep. Take of syrup of poppies, 1 oz.; aniseed-water, 3 oz.; French brandy, ³⁄₄ oz. (or rectified spirit, ¹⁄₂ oz.); calcined magnesia, ¹⁄₄ oz.; mix. An excellent anodyne and antacid for infants.—Dose. A small teaspoonful as required.

ANODYN (Müller, Berlin.) Chiefly for rheumatic pains, toothache, &c. Oil of rosemary, 30 drops; oil of thyme, 10 drops; camphor, 5 grms.; spirit of ammonia, 12 grms.; spirit, 60 grms. (Hager.)

AN′OREXY. Syn. Anorex′ia, L.; Anorexie, Fr., Ger. In pathology, want of, or morbidly diminished appetite, without loathing of food. It is usually symptomatic of other affections. See Appetite, Dyspepsia, &c.

ANOSMIN FOOT POWDER (Dr Oscar Bernar, Vienna). “An unfailing remedy for sweaty feet and bad odour of the feet.” Powdered alum, 21 parts; maize meal, 1 part. (Hager.)

ANOSMIN FOOT WATER (Koch), for a similar purpose. An aqueous solution of tartaric acid.

ANO ZABAGLIONE (-băl-y′ō′-nā). Prep. Put 2 eggs, 3 teaspoonfuls of sugar, and 2 small glassfuls of sherry or marsala, into a chocolate cup, placed in boiling water, or over the fire, and keep the mixture rapidly stirred until it begins to rise and thicken a little; then add158 1 or 2 teaspoonfuls of orange-flower water or rose water, and serve it up in wine-glasses. A pleasant Italian domestic remedy for a cold.

ANT (ănt). Syn. Emm′et, Pis′mire*‡ (pĭz′-); Formi′ca, L.; Fourmi, Fr.; Ameise, Ger.; Æmet, Sax. This well-known little insect belongs to the family formic′′idæ, and the order hymenop′tera. Like the bee, it is a social animal, lives in communities which may be compared to well-regulated republics, and is of three sexes—male, female, neuter. Those belonging to the last alone labour and take care of the ova and young. The red ant contains FORMIC ACID (acid of ants), and a peculiar RESINOUS OIL. Both of these may be obtained by maceration in rectified spirit. A tincture so prepared, and flavoured with aromatics, constitutes Hoffman’s Eau de Magnanimité, once greatly esteemed as an aphrodisiac. See Formica, Formic Acid, Formyle, &c.

ANTAC′ID (-tăs′-ĭd). Syn. Antac′idus, L.; Antacide, &c., Fr.; Säuretilgend, &c., Ger. An agent which neutralises acids or removes acidity. (See below.)

ANTAC′IDS (-tăs′-ĭdz). Syn. Antac′ida, L.; Antacides, &c., Fr. Antacid substances. In medicine, &c., substances which remove or prevent acidity of the stomach, and thus tend to relieve heartburn, dyspepsia, and diarrhœa.

The principal antacids are potassa, soda, ammonia, lime, and magnesia, with their carbonates and bicarbonates. Ammonia is one of the most powerful, and when the acidity is conjoined with nausea and faintness, or is accompanied with symptoms of nervous derangement or hysteria, is undoubtedly the best; when great irritability of the coats of the stomach exist, POTASH is to be preferred; when the acidity is accompanied with diarrhœa, carbonate of lime (prepared chalk), lime-water, or Carara-water; and when with costiveness, MAGNESIA. They may be advantageously combined with some simple aromatic, as ginger, cinnamon, or peppermint. Their preparation, doses, administration, &c., will be found under each in its alphabetical place; and formulæ containing them, under Draughts, Lozenges, Mixtures, &c.

ANTAL′GICS (-tăl′-). Syn. Antal′gica, L. Medicines which relieve pain; anodynes.

ANTAL′KALINES (ănt-ăl′-kă-lĭnz). Syn. Antalkali′na, L. Agents or medicines which correct alkalinity. All the acids except the carbonic are antalkaline.

AN′TE-. In composition, before, contrary, opposite; generally in the first sense. See Anti-.

ANTEPIDEMICUM UNIVERSALE (H. Müller, Copenhagen). “A valuable universal remedy for all sorts of contagious diseases in man or domestic animals.” A fluid like water, with a weak, almost imperceptible, odour of acetic ether. Is composed of spring water, in which perhaps two or three drops of pure carbolic acid are dissolved, and a few drops of acetic ether added to disguise it. (Hager.)

ANTHOK′YAN. Syn. Succ′us vi′olæ prepara′tus, L. The expressed juice of the sweet or purple violet (vi′ola odora′ta—Linn.), defecated, gently heated in glass or earthenware to 192° Fahr., then skimmed, cooled, and filtered; a little rectified spirit is next added, and the following day the whole is again filtered. It must be kept well corked, and in a cool situation.

Uses, &c. Chiefly to make syrup of violets, to colour and flavour liqueurs, and as a chemical test. The London druggists obtain it principally from Lincolnshire.

ANTHOSENZ (Dr Hess, Berlin). General tonic and anodyne balsam. Oil of cloves, 4 parts; oil of geranium, 2 parts; pine-apple essence, 1 part; spirit, 50 parts; coloured with alkanet root. (Hager.)

ANTHRACENE. C₁₄H₁₀. Anthracene is one of the last products passing over in the dry distillation of coal-tar. Dr Calvert says it is “found most abundantly in the ten or fifteen per cent. which comes over between the temperature at which soft pitch is produced and that at which hard pitch is formed.”

Coal-tar contains very variable quantities of anthracene, those tars procured from coals which are richest in naphtha yielding it most abundantly. The coals of South Staffordshire give the largest yield, whilst the Newcastle coals give very little. In consequence of the solubility of anthracene in the oily hydrocarbons which accompany it, owing to “slight elevation of temperature, its extraction can only be carried on advantageously in cold weather.”

Gessert prepares anthracene from coal-tar as follows: He places the last pasty portions (the ‘green grease’) of the coal-tar distillation (which must not be carried beyond the point at which white pitch is formed) first in a centrifugal machine, and then in a hydraulic press at 40°, or subjects the mass heated to 30°-40° directly to pressure in a filter press. The pressed mass consists of about 60% of anthracene; for further purification it is boiled with light tar-oil or petroleum naphtha, and finally heated till it melts. The residue contains 95% of anthracene.

The following method for the purification of crude anthracene contaminated with oily matters is by Schuller:—The crude anthracene is carefully heated to commencing ebullition in a capacious retort connected with a tubulated receiver of glass or earthenware, the lower aperture of which is closed with a fine wire sieve. A strong current of air is159 then blown into the retort with a pair of bellows, whereby the anthracene is driven over in a very short time nearly pure and dry, and condenses in the receiver as a faintly yellowish showy mass. By this method a quantity of anthracene, the purification of which by re-crystallisation or sublimation would take several days, may be purified in as many hours; moreover it is obtained in a pulverulent form, in which it is very readily acted on by oxidising agents. Anthraquinone prepared from crude anthracene may also be obtained by this method in the form of a light yellow powder, resembling flowers of sulphur.

Fritzsche obtained anthracene in crystals exhibiting a beautiful violet colour by exposing a solution of anthracene in coal-tar naphtha to sunshine, until the solution became colourless.

Pure anthracene assumes the form of fluorescent transparent crystals, consisting of four- or six-sided plates, which when seen by transmitted light are of a very pale blue colour, but of a pale violet by reflected light.

The process for obtaining pure anthracene is a very troublesome one. Mr Crookes says:—“A trustworthy method for determining the amount of pure anthracene either in commercial anthracene or in crude green grease is the following:—The melting-point of the sample in question is first determined. 5 to 10 grammes are sufficient for the operation. It is put between thick folds of blotting paper, and placed under a press, between plates which have been previously warmed. The anthracene remaining upon the paper after pressure is weighed. The residue after it has been boiled with a certain quantity of alcohol, filtered, washed with cold alcohol and dried, is weighed as pure anthracene. It is now advisable to determine the melting-point of the purified product, which will generally be 210° C.” Anthracene is only slightly soluble in alcohol, but rather more so in ether and bisulphide of carbon. It is more soluble in hot, but less so in cold benzene. Petroleum boiling between 160° and 195° F. dissolves less than benzene.

“Anthracene dissolves in concentrated sulphuric acid with a green colour, and forms conjugated monsulpho or bisulpho-anthracene acid, according to the temperature employed. Chlorine and bromine give rise to substitution products. Nitric acid acts on it with great violence, with formation of anthraquinone, nitro-anthraquinone, and other compounds according to the temperature and proportion of the substances taken. With picric acid anthracene forms a compound cry

Acetic Acid.	Water.	Acetic Anhydride.
2C₂H₄O₂	- H₂O	= C₄H₆O₃.

COOLEY’S CYCLOPÆDIA
OF
PRACTICAL RECEIPTS
AND
COLLATERAL INFORMATION

PREFACE TO THE SIXTH EDITION

PREFACE

NAMES OF THOSE WHO HAVE CONTRIBUTED TO, OR ASSISTED IN THE REVISION OF, THIS EDITION

ABBREVIATIONS, ETC., USED IN THIS WORK

A CYCLOPÆDIA
OF
PRACTICAL RECEIPTS, PROCESSES,
AND
COLLATERAL INFORMATION

	Alcohol.	Oxygen.	Aldehyd.	Water.
1.	C₂H₆O	+ O	= C₂H₄O	+ H₂O

Chloride of	potassium	15·7
Sulphate of	”	18·4
”	ammonium	13·9

COOLEY’S CYCLOPÆDIA OF PRACTICAL RECEIPTS AND COLLATERAL INFORMATION

PREFACE TO THE SIXTH EDITION

PREFACE

NAMES OF THOSE WHO HAVE CONTRIBUTED TO, OR ASSISTED IN THE REVISION OF, THIS EDITION

ABBREVIATIONS, ETC., USED IN THIS WORK

A CYCLOPÆDIA OF PRACTICAL RECEIPTS, PROCESSES, AND COLLATERAL INFORMATION

COOLEY’S CYCLOPÆDIA
OF
PRACTICAL RECEIPTS
AND
COLLATERAL INFORMATION

A CYCLOPÆDIA
OF
PRACTICAL RECEIPTS, PROCESSES,
AND
COLLATERAL INFORMATION