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SCIENTIFIC AMERICAN SUPPLEMENT NO. 613




NEW YORK, OCTOBER 1, 1887.

Scientific American Supplement. Vol. XXIV., No. 613.

Scientific American established 1845

Scientific American Supplement, $5 a year.

Scientific American and Supplement, $7 a year.

       *       *       *       *       *




TABLE OF CONTENTS.


   I. BIOGRAPHY.--Dr. Morell Mackenzie.--Biographical note and
      portrait of the great English laryngologist--the physician
      of the Prussian Crown Prince.--1 illustration.               9794

  II. BOTANY.--Soudan Coffee.--The _Parkia biglobosa_.--Its
      properties and appearance, with analyses of its beans.--8
      illustrations.                                               9797

      Wisconsin Cranberry Culture.--The great cranberry crop of
      Wisconsin.--The Indian pickers and details of the
      cultivation.                                                 9796

 III. CHEMISTRY.--Analysis of Kola Nut.--A new article
      adapted as a substitute for cocoa and chocolate to military
      and other dietaries.--Its use by the French and German
      governments.                                                 9785

      Carbonic Acid in the Air.--By THOMAS C. VAN NUYS and
      BENJAMIN F. ADAMS, Jr.--The results of eighteen analyses of
      air by Van Nuys apparatus.                                   9785

      The Crimson Line of Phosphorescent Alumina.--Note on Prof.
      Crooke's recent investigation of the anomalies of the oxide
      of aluminum as regards its spectrum.                         9784

  IV. ELECTRICITY.--Electric Time.--By M. LITTMANN.--An
      abstruse research into a natural electric standard of
      time.--The results and necessary formulæ.                    9793

      New Method of Maintaining the Vibration of a
      Pendulum.--Ingenious magneto-electric method of maintaining
      the swinging of a pendulum.                                  9794

      The Part that Electricity Plays in Crystallization.--C.
      Decharme's investigations into this much debated
      question.--The results of his work described.--3
      illustrations.                                               9793

   V. ENGINEERING.--A New Type of Railway Car.--A car with
      lateral passageways, adapted for use in Africa--2
      illustrations.                                               9792

      Centrifugal Pumps at Mare Island Navy Yard, California.--By
      H.R. CORNELIUS.--The great pumps for the Mare Island dry
      docks.--Their capacity and practical working.                9792

      Foundations of the Central Viaduct of Cleveland,
      O.--Details of the foundations of this viaduct, probably
      the largest of its kind ever constructed.                    9792

  VI. METALLURGY.--Chapin Wrought Iron.--By W.H. SEARLES.--An
      interesting account of the combined pneumatic and
      mechanical treatment of pig iron, giving as product a true
      wrought iron.                                                9785

 VII. METEOROLOGY.--On the Cause of Iridescence in
      Clouds.--By G. JOHNSTONE STONEY.--An interesting theory of
      the production of prismatic colors in clouds, referring it
      to interference of light.                                    9798

      The Height of Summer Clouds.--A compendious statement,
      giving the most reliable estimation of the elevations of
      different forms of clouds.                                   9797

VIII. MISCELLANEOUS.--The British Association.--Portraits
      of the president and section presidents of the late
      Manchester meeting of the British Association for the
      Advancement of Science, with report of the address of the
      president, Sir Henry E. Roscoe.--9 illustrations.            9783

  IX. PHYSIOLOGY.--Hypnotism in France.--A valuable review of
      the present status of this subject, now so much studied in
      Paris.                                                       9795

      The Duodenum a Siphon Trap.--By MAYO COLLIER, M.S., etc.--A
      curious observation in anatomy.--The only trap found in the
      intestinal canal.--Its uses.--2 illustrations.               9796

   X. TECHNOLOGY.--Apparatus for Testing Champagne Bottles and
      Corks.--Ingenious apparatus due to Mr. J. Salleron, for use
      especially in the champagne industry.--2 illustrations.      9786

      Celluloid.--Notes of the history and present method of
      manufacture of this widely used substance.                   9785

      Centrifugal Extractors.--By ROBERT F. GIBSON.--The second
      installment of this extensive and important paper, giving
      many additional forms of centrifugal apparatus--12
      illustrations.                                               9789

      Cotton Industries of Japan.--An interesting account of the
      primitive methods of treating cotton by the Japanese.--Their
      methods of ginning, carding, etc., described.                9788

      Gas from Oil.--Notes on a paper read by Dr. Stevenson
      Macadam at a recent meeting of the British Gas Institute,
      giving his results with petroleum gas.                       9787

      Improved Biscuit Machine.--A machine having a capacity for
      making 4,000 small biscuits per minute.--1 illustration.     9787

      Improved Cream Separator.--A centrifugal apparatus for
      dairy use of high capacity.--3 illustrations.                9787

      The Manufacture of Salt near Middlesbrough.--By Sir
      LOWTHIAN BELL, Bart., F.C.S.--The history and origin of
      this industry, the methods used, and the soda ash process
      as there applied.                                            9788

       *       *       *       *       *




THE BRITISH ASSOCIATION.


[Illustration: THE BRITISH ASSOCIATION AT MANCHESTER PORTRAITS OF THE
PRESIDENT AND PRESIDENTS OF SECTIONS ]

The fifty-seventh annual meeting of the British Association was opened
on Wednesday evening, Aug. 31, 1887, at Manchester, by an address from
the president, Sir H.E. Roscoe, M.P. This was delivered in the Free
Trade Hall. The chair was occupied by Professor Williamson, who was
supported by the Bishop of Manchester, Sir F. Bramwell, Professor
Gamgee, Professor Milnes Marshall, Professor Wilkins, Professor Boyd
Dawkins, Professor Ward, and many other distinguished men. A telegram
was read from the retiring president, Sir Wm. Dawson, of Montreal,
congratulating the association and Manchester on this year's meeting.
The new president, Sir H. Roscoe, having been introduced to the
audience, was heartily applauded.

The president, in his inaugural address, said Manchester, distinguished
as the birthplace of two of the greatest discoveries of modern science,
welcomed the visit of the British Association for the third time. Those
discoveries were the atomic theory of which John Dalton was the author,
and the most far-reaching scientific principle of modern times, namely,
that of the conservation of energy, which was given to the world about
the year 1842 by Dr. Joule. While the place suggested these reminders,
the time, the year of the Queen's jubilee, excited a feeling of
thankfulness that they had lived in an age which had witnessed an
advance in our knowledge of nature and a consequent improvement in the
physical, moral, and intellectual well-being of the people hitherto
unknown.


PROGRESS OF CHEMISTRY.

A sketch of that progress in the science of chemistry alone would be
the subject of his address. The initial point was the views of Dalton
and his contemporaries compared with the ideas which now prevail; and
he (the president) examined this comparison by the light which the
research of the last fifty years had thrown on the subject of the
Daltonian atoms, in the three-fold aspect of their size,
indivisibility, and mutual relationships, and their motions.


SIZE OF THE ATOM.

As to the size of the atom, Loschmidt, of Vienna, had come to the
conclusion that the diameter of an atom of oxygen or nitrogen was the
ten-millionth part of a centimeter. With the highest known magnifying
power we could distinguish the forty-thousandth part of a centimeter.
If, now, we imagine a cubic box each of whose sides had this length,
such a box, when filled with air, would contain from sixty to a
hundred millions of atoms of oxygen and nitrogen. As to the
indivisibility of the atom, the space of fifty years had completely
changed the face of the inquiry. Not only had the number of distinct,
well-established elementary bodies increased from fifty-three in 1837
to seventy in 1887, but the properties of these elements had been
studied, and were now known with a degree of precision then undreamt
of. Had the atoms of our present elements been made to yield? To this
a negative answer must undoubtedly be given, for even the highest of
terrestrial temperatures, that of the electric spark, had failed to
shake any one of these atoms in two. This was shown by the results
with which spectrum analysis had enriched our knowledge. Terrestrial
analysis had failed to furnish favorable evidence; and, turning to the
chemistry of the stars, the spectra of the white, which were
presumably the hottest stars, furnished no direct evidence that a
decomposition of any terrestrial atom had taken place; indeed, we
learned that the hydrogen atom, as we know it here, can endure
unscathed the inconceivably fierce temperature of stars presumably
many times more fervent than our sun, as Sirius and Vega. It was
therefore no matter for surprise if the earth-bound chemist should for
the present continue to regard the elements as the unalterable
foundation stones upon which his science is based.


ATOMIC MOTION.

Passing to the consideration of atoms in motion, while Dalton and
Graham indicated that they were in a continual state of motion, we
were indebted to Joule for the first accurate determination of the
rate of that motion. Clerk-Maxwell had calculated that a hydrogen
molecule, moving at the rate of seventy miles per minute, must, in one
second of time, knock against others no fewer than eighteen thousand
million times. This led to the reflection that in nature there is no
such thing as great or small, and that the structure of the smallest
particle, invisible even to our most searching vision, may be as
complicated as that of any one of the heavenly bodies which circle
round our sun. How did this wonderful atomic motion affect their
chemistry?


ATOMIC COMBINATION.

Lavoisier left unexplained the dynamics of combustion; but in 1843,
before the chemical section of the association meeting at Cork, Dr.
Joule announced the discovery which was to revolutionize modern
science, namely, the determination of the mechanical equivalent of
heat. Every change in the arrangement of the particles he found was
accompanied by a definite evolution or an absorption of heat. Heat was
evolved by the clashing of the atoms, and this amount was fixed and
definite. Thus to Joule we owe the foundation of chemical dynamics and
the basis of thermal chemistry. It was upon a knowledge of the mode of
arrangement of atoms, and on a recognition of their distinctive
properties, that the superstructure of modern organic chemistry
rested. We now assumed on good grounds that the atom of each element
possessed distinct capabilities of combination. The knowledge of the
mode in which the atoms in the molecule are arranged had given to
organic chemistry an impetus which had overcome many experimental
obstacles, and organic chemistry had now become synthetic.

Liebig and Wohler, in 1837, foresaw the artificial production in the
laboratories of all organic substances so far as they did not
constitute a living organism. And after fifty years their prophecy had
been fulfilled, for at the present time we could prepare an artificial
sweetening principle, an artificial alkaloid, and salacine.


SYNTHESIS.

We know now that the same laws regulate the formation of chemical
compounds in both animate and inanimate nature, and the chemist only
asked for a knowledge of the constitution of any definite chemical
compounds found in the organic world in order to be able to promise to
prepare it artificially. Seventeen years elapsed between Wohler's
discovery of the artificial production of urea and the next real
synthesis, which was accomplished by Kolbe, when in 1845 he prepared
acetic acid from its elements. Since then a splendid harvest of
results had been gathered in by chemists of all nations. In 1834 Dumas
made known the law of substitution, and showed that an exchange could
take place between the constituent atoms in a molecule, and upon this
law depended in great measure the astounding progress made in the wide
field of organic synthesis.

Perhaps the most remarkable result had been the production of an
artificial sweetening agent, termed saccharin, 250 times sweeter than
sugar, prepared by a complicated series of reactions from coal tar.
These discoveries were not only of scientific interest, for they had
given rise to the industry of coal tar colors, founded by our
countryman Perkin, the value of which was measured by millions
sterling annually. Another interesting application of synthetic
chemistry to the needs of everyday life was the discovery of a series
of valuable febrifuges, of which antipyrin might be named as the most
useful.

An important aspect in connection with the study of these bodies was
the physiological value which had been found to attach to the
introduction of certain organic radicals, so that an indication was
given of the possibility of preparing a compound which will possess
certain desired physiological properties, or even to foretell the kind
of action which such bodies may exert on the animal economy. But now
the question might well be put, Was any limit set to this synthetic
power of the chemist? Although the danger of dogmatizing as to the
progress of science had already been shown in too many instances, yet
one could not help feeling that the barrier between the organized and
unorganized worlds was one which the chemist at present saw no chance
of breaking down. True, there were those who professed to foresee that
the day would arrive when the chemist, by a succession of constructive
efforts, might pass beyond albumen, and gather the elements of
lifeless matter into a living structure. Whatever might be said
regarding this from other standpoints, the chemist could only say that
at present no such problem lay within his province.

Protoplasm, with which the simplest manifestations of life are
associated, was not a compound, but a structure built up of compounds.
The chemist might successfully synthesize any of its component
molecules, but he had no more reason to look forward to the synthetic
production of the structure than to imagine that the synthesis of
gallic acid led to the artificial production of gall nuts. Although
there was thus no prospect of effecting a synthesis of organized
material, yet the progress made in our knowledge of the chemistry of
life during the last fifty years had been very great, so much so
indeed that the sciences of physiological and of pathological
chemistry might be said to have entirely arisen within that period.


CHEMISTRY OF VITAL FUNCTIONS.

He would now briefly trace a few of the more important steps which had
marked the recent study of the relations between the vital phenomena
and those of the inorganic world. No portion of the science of
chemistry was of greater interest or greater complexity than that
which, bearing on the vital functions both of plants and of animals,
endeavored to unravel the tangled skein of the chemistry of life, and
to explain the principles according to which our bodies live, and
move, and have their being. If, therefore, in the less complicated
problems with which other portions of our science have to deal, we
found ourselves often far from possessing satisfactory solutions, we
could not be surprised to learn that with regard to the chemistry of
the living body--whether vegetable or animal--in health or disease, we
were still farther from a complete knowledge of phenomena, even those
of fundamental importance.

Liebig asked if we could distinguish, on the one hand, between the
kind of food which goes to create warmth and, on the other, that by
the oxidation of which the motions and mechanical energy of the body
are kept up. He thought he was able to do this, and he divided food
into two categories. The starchy or carbo-hydrate food was that, said
he, which by its combustion provided the warmth necessary for the
existence and life of the body. The albuminous or nitrogenous
constituents of our food, the flesh meat, the gluten, the casein out
of which our muscles are built up, were not available for the purpose
of creating warmth, but it was by the waste of those muscles that the
mechanical energy, the activity, the motions of the animal are
supplied.

Soon after the promulgation of these views, J.R. Mayer warmly attacked
them, throwing out the hypothesis that all muscular action is due to
the combustion of food, and not to the destruction of muscle.

What did modern research say to this question? Could it be brought to
the crucial test of experiment? It could; but how? In the first place,
we could ascertain the work done by a man or any other animal; we
could measure this work in terms of our mechanical standard, in
kilogramme-meters or foot-pounds. We could next determine what was the
destruction of nitrogenous tissue at rest and under exercise by the
amount of nitrogenous material thrown off by the body. And here we
must remember that these tissues were never completely burned, so that
free nitrogen was never eliminated. If now we knew the heat value of
the burned muscle, it was easy to convert this into its mechanical
equivalent and thus measure the energy generated. What was the result?

Was the weight of muscle destroyed by ascending the Faulhorn or by
working on the treadmill sufficient to produce on combustion heat
enough when transformed into mechanical exercise to lift the body up
to the summit of the Faulhorn or to do the work on the treadmill?

Careful experiment had shown that this was so far from being the case
that the actual energy developed was twice as great as that which
could possibly be produced by the oxidation of the nitrogenous
constituents eliminated from the body during twenty-four hours. That
was to say, taking the amount of nitrogenous substance cast off from
the body, not only while the work was being done, but during
twenty-four hours, the mechanical effect capable of being produced by
the muscular tissue from which this cast-off material was derived
would only raise the body half way up the Faulhorn, or enable the
prisoner to work half his time on the treadmill. Hence it was clear
that Liebig's proposition was not true.

The nitrogenous constituents of the food did doubtless go to repair
the waste of muscle, which, like every other portion of the body,
needed renewal, while the function of the non-nitrogenous food was not
only to supply the animal heat, but also to furnish, by its oxidation,
the muscular energy of the body. We thus came to the conclusion that
it was the potential energy of the food which furnished the actual
energy of the body, expressed in terms either of heat or of mechanical
work.

But there was one other factor which came into play in this question
of mechanical energy, and must be taken into account; and this factor
we were as yet unable to estimate in our usual terms. It concerned the
action of the mind on the body, and although incapable of exact
expression, exerted none the less an important influence on the
physics and chemistry of the body, so that a connection undoubtedly
existed between intellectual activity or mental work and bodily
nutrition. What was the expenditure of mechanical energy which
accompanied mental effort was a question which science was probably
far from answering; but that the body experienced exhaustion as the
result of mental activity was a well-recognized fact.


CHEMISTRY OF VEGETATION.

The phenomena of vegetation, no less than those of the animal world,
had, however, during the last fifty years been placed by the chemist
on an entirely new basis.

Liebig, in 1860, asserted that the whole of the carbon of vegetation
was obtained from the atmospheric carbonic acid, which, though only
present in the small relative proportion of four parts in 10,000 of
air, was contained in such absolutely large quantity that if all the
vegetation on the earth's surface were burned, the proportion of
carbonic acid which would thus be thrown into the air would not be
sufficient to double the present amount. That this conclusion was
correct needed experimental proof, but such proof could only be given
by long-continued and laborious experiment.

It was to our English agricultural chemists, Lawes and Gilbert, that
we owed the complete experimental proof required, and this experiment
was long and tedious, for it had taken forty-four years to give a
definite reply.

At Rothamsted a plot was set apart for the growth of wheat. For
forty-four successive years that field had grown wheat without the
addition of any carbonized manure, so that the only possible source
from which the plant could obtain the carbon for its growth was the
atmospheric carbonic acid. The quantity of carbon which on an average
was removed in the form of wheat and straw from a plot manured only
with mineral matter was 1,000 lb., while on another plot, for which a
nitrogenous manure was employed, 1,500 lb. more carbon was annually
removed, or 2,500 lb. of carbon were removed by this crop annually
without the addition of any carbonaceous manure. So that Liebig's
prevision had received a complete experimental verification.


CHEMICAL PATHOLOGY.

Touching us as human beings even still more closely than the foregoing
was the influence which chemistry had exerted on the science of
pathology, and in no direction had greater progress been made than in
the study of micro-organisms in relation to health and disease. In the
complicated chemical changes to which we gave the names of
fermentation and putrefaction, Pasteur had established the fundamental
principle that these processes were inseparately connected with the
life of certain low forms of organisms. Thus was founded the science
of bacteriology, which in Lister's hands had yielded such splendid
results in the treatment of surgical cases, and in those of Klebs,
Koch, and others, had been the means of detecting the cause of many
diseases both in man and animals, the latest and not the least
important of which was the remarkable series of successful researches
by Pasteur into the nature and mode of cure of that most dreadful of
maladies, hydrophobia. The value of his discovery was greater than
could be estimated by its present utility, for it showed that it might
be possible to avert other diseases besides hydrophobia by the
adoption of a somewhat similar method of investigation and of
treatment.

Here it might seem as if we had outstepped the boundaries of
chemistry, and had to do with phenomena purely vital. But recent
research indicated that this was not the case, and pointed to the
conclusion that the microscopist must again give way to the chemist,
and that it was by chemical rather than biological investigation that
the causes of diseases would be discovered, and the power of removing
them obtained. For we learned that the symptoms of infective diseases
were no more due to the microbes which constituted the infection than
alcoholic intoxication was produced by the yeast cell, but that these
symptoms were due to the presence of definite chemical compounds, the
result of the life of these microscopic organisms. So it was to the
action of these poisonous substances formed during the life of the
organism, rather than to that of the organism itself, that the special
characteristics of the disease were to be traced, for it had been
shown that the disease could be communicated by such poisons in the
entire absence of living organisms.

Had time permitted, he would have wished to have illustrated the
dependence of industrial success upon original investigation, and to
have pointed out the prodigious strides which chemical industry in
this country had made during the fifty years of her Majesty's reign.
As it was, he must be content to remark how much our modern life, both
in its artistic and useful aspects, owed to chemistry, and therefore
how essential a knowledge of the principles of the science was to all
who had the industrial progress of the country at heart. The country
was now beginning to see that if she was to maintain her commercial
and industrial supremacy, the education of her people from top to
bottom must be carried out on new lines. The question how this could
be most safely and surely accomplished was one of transcendent
national importance, and the statesman who solved this educational
problem would earn the gratitude of generations yet to come.

In welcoming the unprecedentedly large number of foreign men of
science who had on this occasion honored the British Association by
their presence, he hoped that that meeting might be the commencement
of an international scientific organization, the only means nowadays
existing of establishing that fraternity among nations from which
politics appeared to remove them further and further, by absorbing
human powers and human work, and directing them to purposes of
destruction. It would indeed be well if Great Britain, which had
hitherto taken the lead in so many things that are great and good,
should now direct her attention to the furthering of international
organizations of a scientific nature. A more appropriate occasion than
the present meeting could perhaps hardly be found for the inauguration
of such a movement. But whether this hope were realized or not, they
all united in that one great object, the search after truth for its
own sake, and they all, therefore, might join in re-echoing the words
of Lessing: "The worth of man lies not in the truth which he
possesses, or believes that he possesses, but in the honest endeavor
which he puts forth to secure that truth; for not by the possession of
truth, but by the search after it, are the faculties of man enlarged,
and in this alone consists his ever-growing perfection. Possession
fosters content, indolence, and pride. If God should hold in his right
hand all truth, and in his left hand the ever-active desire to seek
truth, though with the condition of perpetual error, I would humbly
ask for the contents of the left hand, saying, 'Father, give me this;
pure truth is only for thee.'"

At the close of his address a vote of thanks was passed to the
president, on the motion of the Mayor of Manchester, seconded by
Professor Asa Gray, of Harvard College. The president mentioned that
the number of members is already larger than at any previous annual
meeting, namely, 3,568, including eighty foreigners.

       *       *       *       *       *




THE CRIMSON LINE OF PHOSPHORESCENT ALUMINA.


Crookes has presented to the Royal Society a paper on the color
emitted by pure alumina when submitted to the electric discharge _in
vacuo_, in answer to the statements of De Boisbaudran. In 1879 he had
stated that "next to the diamond, alumina, in the form of ruby, is
perhaps the most strikingly phosphorescent stone I have examined. It
glows with a rich, full red; and a remarkable feature is that it is of
little consequence what degree of color the earth or stone possesses
naturally, the color of the phosphorescence is nearly the same in all
cases; chemically precipitated amorphous alumina, rubies of a pale
reddish yellow, and gems of the prized 'pigeon's blood' color glowing
alike in the vacuum." These results, as well as the spectra obtained,
he stated further, corroborated Becquerel's observations. In
consequence of the opposite results obtained by De Boisbaudran,
Crookes has now re-examined this question with a view to clear up the
mystery. On examining a specimen of alumina prepared from tolerably
pure aluminum sulphate, shown by the ordinary tests to be free from
chromium, the bright crimson line, to which the red phosphorescent
light is due, was brightly visible in its spectrum. The aluminum
sulphate was then, in separate portions, purified by various processes
especially adapted to separate from it any chromium that might be
present; the best of these being that given by Wohler, solution in
excess of potassium hydrate and precipitation of the alumina by a
current of chlorine. The alumina filtered off, ignited, and tested in
a radiant matter tube gave as good a crimson line spectrum as did that
from the original sulphate.

A repetition of this purifying process gave no change in the result.
Four possible explanations are offered of the phenomena observed: "(1)
The crimson line is due to alumina, but it is capable of being
suppressed by an accompanying earth which concentrates toward one end
of the fractionations; (2) the crimson line is not due to alumina, but
is due to the presence of an accompanying earth concentrating toward
the other end of the fractionations; (3) the crimson line belongs to
alumina, but its full development requires certain precautions to be
observed in the time and intensity of ignition, degree of exhaustion,
or its absolute freedom from alkaline and other bodies carried down by
precipitated alumina and difficult to remove by washing; experience
not having yet shown which of these precautions are essential to the
full development of the crimson line and which are unessential; and
(4) the earth alumina is a compound molecule, one of its constituent
molecules giving the crimson line. According to this hypothesis,
alumina would be analogous to yttria."--_Nature._

       *       *       *       *       *




CARBONIC ACID IN THE AIR.

By THOMAS C. VAN NUYS and BENJAMIN F. ADAMS, JR.


During the month of April, 1886, we made eighteen estimations of
carbonic acid in the air, employing Van Nuys' apparatus,[1] recently
described in this journal. These estimations were made in the
University Park, one-half mile from the town of Bloomington. The park
is hilly, thinly shaded, and higher than the surrounding country. The
formation is sub-carboniferous and altitude 228 meters. There are no
lowlands or swamps near. The estimations were made at 10 A.M.

  [Footnote 1: See SCI. AM. SUPPLEMENT No. 577.]

The air was obtained one-half meter from the ground and about 100
meters from any of the university buildings. The number of volumes of
carbonic acid is calculated at zero C. and normal pressure 760 mm.

  --------+----------+--------------+------------------------
          |          | Vols. CO_{2} |
   Date.  |   Bar.   |  in 100,000  | State of Weather.
          | Pressure |  Vols. Air.  |
  --------+----------+--------------+------------------------
  April 2 |  743.5   |    28.86     | Cloudy, snow on ground.
    "   5 |  743.5   |    28.97     |    "     "   "    "
    "   6 |  735     |    28.61     | Snowing.
    "   7 |  744.5   |    28.63     | Clear, snow on ground.
    "   8 |  748     |    27.59     |   "    thawing.
    "   9 |  747.5   |    28.10     |   "       "
    "  12 |  744     |    28.04     | Cloudy.
    "  13 |  744     |    28.10     | Clear.
    "  14 |  743.5   |    28.98     |   "
    "  15 |  750.5   |    28.17     | Raining.
    "  19 |  748     |    28.09     | Clear.
    "  20 |  746     |    27.72     |   "
    "  21 |  746     |    28.16     |   "
    "  22 |  741.5   |    27.92     |   "
    "  23 |  740     |    28.12     |   "
    "  24 |  738.5   |    28.15     |   "
    "  25 |  738.5   |    27.46     |   "
    "  28 |  738     |    27.34     |   "
  --------+----------+--------------+------------------------

The average number of volumes of carbonic acid in 100,000 volumes of
air is 28.16, the maximum number is 28.98, and the minimum 27.34.
These results agree with estimations made within the last ten or
fifteen years. Reiset[2] made a great number of estimations from
September 9, 1872, to August 20, 1873, the average of which is 29.42.
Six years later[3] he made many estimations from June to November, the
average of which is 29.78. The average of Schultze's[4] estimations is
29 2. The results of estimations of carbonic acid in the air, made
under the supervision of Munz and Aubin[5] in October, November, and
December, 1882, at the stations where observations were made of the
transit of Venus by astronomers sent out by the French government,
yield the average, for all stations north of the equator to latitude
29° 54' in Florida, 28.2 volumes carbonic acid in 100,000 volumes air,
and for all stations south of the equator 27.1 volumes. The average of
Claesson's[6] estimations is 27.9 volumes, his maximum number is 32.7,
and his minimum is 23.7. It is apparent, from the results of
estimations of carbonic acid of the air of various parts of the globe,
by the employment of apparatus with which errors are avoided, that the
quantity of carbonic acid is subject to slight variation, and not, as
stated in nearly all text books of science, from 4 to 6 volumes in
10,000 volumes of air; and it is further apparent that the law of
Schloesing[7] holds good. By this law the carbonic acid of an
atmosphere in contact with water containing calcium or magnesium
carbonate in solution is dissolved according to the tension of the
carbonic acid; that is, by an increased quantity its tension
increases, and more would pass in solution in the form of
bicarbonates. On the other hand, by diminishing the quantity of
carbonic acid in the atmosphere, some of the bicarbonates would
decompose and carbonic acid pass into the atmosphere.

  [Footnote 2: Comptes Rendus, 88, 1007.]
  [Footnote 3: Comptes Rendus, 90, 1144.]
  [Footnote 4: Chem. Centralblatt, 1872 and 1875.]
  [Footnote 5: Comptes Rendus, 96, 1793.]
  [Footnote 6: Berichte der deutsch chem. Gesellschaft, 9, 174.]
  [Footnote 7: Comptes Rendus, 74, 1552, and 75, 70.]

Schloesing's law has been verified by R. Engel[8].

  [Footnote 8: Comptes Rendus, 101, 949.]

The results of estimations of bases and carbonic acid in the water of
the English Channel lead Schloesing[9] to conclude that the carbonic
acid combined with normal carbonates, forming bicarbonates, dissolved
in the water of the globe is ten times greater in quantity than that
of the atmosphere, and on account of this available carbonic acid, if
the atmosphere should be deprived of some of its carbonic acid, the
loss would soon be supplied.

  [Footnote 9: Comptes Rendus, 90, 1410.]

As, in nearly all of the methods which were employed for estimating
carbonic acid in the air, provision is not made for the exclusion of
air not measured containing carbonic acid from the alkaline fluid
before titrating or weighing, the results are generally too high and
show a far greater variation than is found by more exact methods. For
example, Gilm[10] found from 36 to 48 volumes; Levy's[11] average is
34 volumes; De Luna's[12] 50 volumes; and Fodor's,[13] 38.9 volumes.
Admitting that the quantity of carbonic acid in the air is subject to
variation, yet the results of Reiset's and Schultze's estimations go
to prove that the variation is within narrow limits.

  [Footnote 10: Sitzungsher. d. Wien. Akad. d. Wissenschaften, 34, 257.]
  [Footnote 11: Ann. d. l'Observ. d. Mountsouris, 1878 and 1879.]
  [Footnote 12: Estudios quimicos sobre el aire atmosferico, Madrid, 1860.]
  [Footnote 13: Hygien. Untersuch., 1, 10.]

                  Indiana University Chemical Laboratory,
                     Bloomington, Indiana.
                        --_Amer. Chem. Journal._

       *       *       *       *       *




ANALYSIS OF KOLA NUT.


Alkaloids or crystallizable principles:

                                                     Per Cent.
    Caffeine.                                           2.710
    Theobromine.                                        0.084
    Bitter principle.                                   0.018
        Total alkaloids.                                -----   2.812
  Fatty matters:
    Saponifiable fat or oil.                            0.734
    Essential oil.                                      0.081
        Total oils.                                     -----   0.815
  Resinoid matter (_sol. in abs. alcohol_)              1.012

  Sugar:
    Glucose (_reduces alkaline cuprammonium_).          3.312
    Sucrose? (_red. alk. cupram. after inversion_)[1].  0.602
        Total sugars.                                   -----   3.914

  Starch, gum, etc.:
    Gum (_soluble in H2O at 90° F_.).                   4.876
    Starch.                                            28.990
    Amidinous matter (_coloring with iodine_).          2.130
        Total gum and fecula.                           -----  35.999
  Albuminoid matters.                                           8.642
  Red and other coloring matters.                               3.670
  Kolatannic acids.                                             1.204

  Mineral matter:
    Potassa.                                            1.415
    Chlorine.                                           0.702
    Phosphoric acid.                                    0.371
    Other salts, etc.                                   2.330
        Total ash.                                      -----   4.818
  Moisture.                                                     9.722
  Ligneous matter and loss.                                    27.395
                                                              -------
                                                              100.000

  [Footnote 1: Inverted by boiling with a 2.5 per cent. solution of
               citric acid for ten minutes.]

Both the French and German governments are introducing it into their
military dietaries, and in England several large contract orders
cannot yet be filled, owing to insufficiency of supply, while a
well-known cocoa manufacturing firm has taken up the preparation of
kola chocolate upon a commercial scale.--_W. Lascelles-Scott, in Jour.
Soc. Arts._

       *       *       *       *       *




CHAPIN WROUGHT IRON.

By W.H. SEARLES, Chairman of the Committee, Civil Engineers' Club
of Cleveland, O.


Notwithstanding the wonderful development of our steel industries in
the last decade, the improvements in the modes of manufacture, and the
undoubted strength of the metal under certain circumstances,
nevertheless we find that steel has not altogether met the
requirements of engineers as a structural material. Although its
breaking strain and elastic limit are higher than those of wrought
iron, the latter metal is frequently preferred and selected for
tensile members, even when steel is used under compression in the same
structure. The Niagara cantilever bridge is a notable instance of this
practice. When steel is used in tension its working strains are not
allowed to be over fifty per cent. above those adopted for wrought
iron.

The reasons for the suspicion with which steel is regarded are well
understood. Not only is there a lack of uniformity in the product, but
apparently the same steel will manifest very different results under
slight provocation. Steel is very sensitive, not only to slight
changes in chemical composition, but also to mechanical treatment,
such as straightening, bending, punching, planing, heating, etc.
Initial strains may be developed by any of these processes that would
seriously affect the efficiency of the metal in service.

Among the steels, those that are softer are more serviceable and
reliable than the harder ones, especially whereever shocks and
concussions or rapidly alternating strains are to be endured. In other
words, the more nearly steel resembles good wrought iron, the more
certain it is to render lasting service when used within appropriate
limits of strain. Indeed, a wrought iron of fine quality is better
calculated to endure fatigue than any steel. This is particularly
noticeable in steam hammer pistons, propeller shafts, and railroad
axles. A better quality of wrought iron, therefore, has long been a
desideratum, and it appears now that it has at last been found.

Several years since, a pneumatic process of manufacturing wrought iron
was invented and patented by Dr. Chapin, and an experimental plant was
erected near Chicago. Enough was done to demonstrate, first, that an
iron of unprecedentedly good qualities was attainable from common pig;
and second, that the cost of its manufacture would not exceed that of
Bessemer steel. Nevertheless, owing to lack of funds properly to push
the invention against the jealous opposition which it encountered, the
enterprise came to a halt until quite recently, when its merits found
a champion in Gustav Lindenthal, C.E., member of this club, who is
now the general manager of the Chapin Pneumatic Iron Co., and under
whose direction this new quality of iron will soon be put upon the
market.

The process of manufacture is briefly as follows: The pig metal, after
being melted in a cupola and tapped into a discharging ladle, is
delivered into a Bessemer converter, in which the metal is largely
relieved of its silicon, sulphur, carbon, etc., by the ordinary
pneumatic process. At the end of the blow the converter is turned down
and its contents discharged into a traveling ladle, and quickly
delivered to machines called ballers, which are rotary reverberatory
furnaces, each revolving on a horizontal axis. In the baller the iron
is very soon made into a ball without manual aid. It is then lifted
out by means of a suspended fork and carried to a Winslow squeezer,
where the ball is reduced to a roll twelve inches in diameter. Thence
it is taken to a furnace for a wash heat, and finally to the muck
train.

No reagents are employed, as in steel making or ordinary iron
puddling. The high heat of the metal is sufficient to preserve its
fluidity during its transit from the converter to the baller; and the
cinder from the blow is kept in the ladle.

The baller is a bulging cylinder having hollow trunnions through which
the flame passes. The cylinder is lined with fire brick, and this in
turn is covered with a suitable refractory iron ore, from eight to ten
inches thick, grouted with pulverized iron ore, forming a bottom, as
in the common puddling furnace. The phosphorus of the iron, which
cannot be eliminated in the intense heat of the converter, is,
however, reduced to a minimum in the baller at a much lower
temperature and on the basic lining. The process wastes the lining
very slightly indeed. As many as sixty heats have been taken off in
succession without giving the lining any attention. The absence of any
reagent leaves the iron simply pure and homogeneous to a degree never
realized in muck bars made by the old puddling process. Thus the
expense of a reheating and rerolling to refine the iron is obviated.
It was such iron as here results that Bessemer, in his early
experiments, was seeking to obtain when he was diverted from his
purpose by his splendid discoveries in the art of making steel. So
effective is the new process, that even from the poorest grades of pig
may be obtained economically an iron equal in quality to the refined
irons made from the best pig by the ordinary process of puddling.

Numerous tests of the Chapin irons have been made by competent and
disinterested parties, and the results published. The samples here
noted were cut and piled only once from the muck bar.

Sample A was made from No. 3 mill cinder pig.

Sample B was made from No. 4 mill pig and No. 3 Bessemer pig, half and
half.

Sample C was made from No. 3 Bessemer pig, with the following results:

            Sample.                 A         B         C
  Tensile strength per sq. in.    56,000    60,772    64,377
  Elastic limit.                  34,000      ....    36,000
  Extension, per cent.              11.8      ....      17.0
  Reduction of area, per cent.      65.0      16.0      33.0

The tensile strength of these irons made by ordinary puddling would be
about 38,000, 40,000, and 42,000 respectively, or the gain of the iron
in tensile strength by the Chapin process is about fifty per cent. Not
only so, but these irons made in this manner from inferior pig show a
higher elastic limit and breaking strain than are commonly specified
for refined iron of best quality. The usual specifications are for
refined iron: Tensile strength, 50,000; elongation, 15 per cent.;
elastic limit, 26,000; reduction, 25 cent.

Thus the limits of the Chapin iron are from 12 to 20 per cent. above
those of refined iron, and not far below those of structural steel,
while there is a saving of some four dollars per ton in the price of
the pig iron from which it can be made. When made from the best pig
metal its breaking and elastic limits will probably reach 70,000 and
40,000 pounds respectively. If so, it will be a safer material than
steel under the same working strains, owing to its greater resilience.

Such results are very interesting in both a mechanical and economical
point of view. Engineers will hail with delight the accession to the
list of available building materials of a wrought iron at once fine,
fibrous, homogeneous, ductile, easily weldable, not subject to injury
by the ordinary processes of shaping, punching, etc., and having a
tensile strength and elastic limit nearly equal to any steel that
could safely be used in the same situation.

A plant for the manufacture of Chapin iron is now in course of
erection at Bethlehem, Pa., and there is every reason to believe that
the excellent results attained in Chicago will be more than reached in
the new works.--_Proceed. Jour. Asso. of Eng. Societies_.

       *       *       *       *       *




CELLULOID.


Professor Sadler, of the University of Pennsylvania, has lately given
an account of the development and method of the manufacture of
celluloid. Alexander Parkes, an Englishman, invented this remarkable
substance in 1855, but after twelve years quit making it because of
difficulties in manipulation, although he made a fine display at the
Paris Exposition of 1867. Daniel Spill, also of England, began
experiments two years after Parkes, but a patent of his for dissolving
the nitrated wood fiber, or "pyroxyline," in alcohol and camphor was
decided by Judge Blatchford in a suit brought against the Celluloid
Manufacturing Company to be valueless. No further progress was made
until the Hyatt Brothers, of Albany, N.Y., discovered that gum
camphor, when finely divided, mixed with the nitrated fiber and then
heated, is a perfect solvent, giving a homogeneous and plastic mass.
American patents of 1870 and 1874 are substantially identical with
those now in use in England. In France there is only one factory, and
there is none elsewhere on the Continent, one in Hanover having been
given up on account of the explosive nature of the stuff. In this
country pure cellulose is commonly obtained from paper makers, in the
form of tissue paper, in wide rolls; this, after being nitrated by a
bath of mixed nitric and sulphuric acids, is thoroughly washed and
partially dried. Camphor is then added, and the whole is ground
together and thoroughly mixed. At this stage coloring matter may be
put in. A little alcohol increases the plasticity of the mass, which
is then treated for some time to powerful hydraulic pressure. Then
comes breaking up the cakes and feeding the fragments between heated
rolls, by which the amalgamation of the whole is completed. Its
perfect plasticity allows it to be rolled into sheets, drawn into
tubes, or moulded into any desired shape.--_Jewelers' Journal._

       *       *       *       *       *




APPARATUS FOR TESTING CHAMPAGNE BOTTLES AND CORKS.


Mr. J. Salleron has devised several apparatus which are destined to
render valuable service in the champagne industry. The apparently
simple operation of confining the carbonic acid due to fermentation in
a bottle in order to blow the cork from the latter with force at a
given moment is not always successful, notwithstanding the skill and
experience of the manipulator. How could it be otherwise?

Everything connected with the production of champagne wine was but
recently unknown and unexplained. The proportioning of the sugar
accurately dates, as it were, from but yesterday, and the measurement
of the absorbing power of wine for carbonic acid has but just entered
into practice, thanks to Mr. Salleron's absorptiometer. The real
strength of the bottles, and the laws of the elasticity of glass and
its variation with the temperature, are but little known. Finally, the
physical constitution of cork, its chemical composition, its
resistance to compression and the dissolving action of the wine, must
be taken into consideration. In fact, all the elements of the
difficult problem of the manufacture of sparkling wine show that there
is an urgent necessity of introducing scientific methods into this
industry, as without them work can now no longer be done.

No one has had a better opportunity to show how easy it is to convert
the juice of the grape into sparkling wine through a series of simple
operations whose details are known and accurately determined, so we
believe it our duty to recommend those of our readers who are
particularly interested in this subject to read Mr. Salleron's book on
sparkling wine. We shall confine ourselves in this article to a
description of two of the apparatus invented by the author for testing
the resistance of bottles and cork stoppers.

It is well, in the first place, to say that one of the important
elements in the treatment of sparkling wine is the normal pressure
that it is to produce in the bottles. After judicious deductions and
numerous experiments, Mr. Salleron has adopted for the normal pressure
of highly sparkling wines five atmospheres at the temperature of the
cellar, which does not exceed 10 degrees. But, in a defective cellar,
the bottles may be exposed to frost in winter and to a temperature of
25° in summer, corresponding to a tension of ten atmospheres. It may
naturally be asked whether bottles will withstand such an ordeal. Mr.
Salleron has determined their resistance through the process by which
we estimate that of building materials, viz., by measuring the limit
of their elasticity, or, in other words, the pressure under which they
take on a new permanent volume. In fact, glass must be assimilated to
a perfectly elastic body; and bottles expand under the internal
pressure that they support. If their resistance is insufficient, they
continue to increase in measure as the pressure is further prolonged,
and at every increase in permanent capacity, their resistance
diminishes.

[Illustration: Fig. 1.--MACHINE FOR TESTING BOTTLES.]

The apparatus shown in Fig. 1 is called an elasticimeter, and permits
of a preliminary testing of bottles. The bottle to be tested is put
into the receptacle, A B, which is kept full of water, and when it has
become full, its neck is played between the jaws of the clamp, _p_.
Upon turning the hand wheel, L, the bottle and the receptacle that
holds it are lifted, and the mouth of the bottle presses against a
rubber disk fixed under the support, C D. The pressure of the neck of
the bottle against this disk is such that the closing is absolutely
hermetical. The support, C D, contains an aperture which allows the
interior of the bottle to communicate with a glass tube, _a b_, which
thus forms a prolongation of the neck of the bottle. This tube is very
narrow and is divided into fiftieths of a cubic centimeter. A
microscope, _m_, fixed in front of the tube, magnifies the divisions,
and allows the position of the level of the water to be ascertained to
within about a millionth of a cubic centimeter.

A force and suction pump, P, sucks in air through the tube, _t_, and
compresses it through the tube, _t'_, in the copper tube, T, which
communicates with the glass tube, _a b_, after passing through the
pressure gauge, M. This pump, then, compresses the air in the bottle,
and the gauge accurately measures its pressure.

To make a test, after the bottle full of water has been fastened under
the support, C D, the cock, _s_, is opened and the liquid with which
the small reservoir, R, has been filled flows through an aperture above
the mouth of the bottle and rises in the tube, _a b_. When its level
reaches the division, O, the cock, _s_, is closed. The bottle and its
prolongation, _a b_, are now exactly full of water without any air
bubbles.

The pump is actuated, and, in measure as the pressure rises, the level
of the liquid in the tube, _a b_, is seen to descend. This descent
measures the expansion or flexion of the bottle as well as the
compression of the water itself. When the pressure is judged to be
sufficient, the button, _n_, is turned, and the air compressed by the
pump finding an exit, the needle of the pressure gauge will be seen to
redescend and the level of the tube, _a b_, to rise.

If the glass of the bottle has undergone no permanent deformation, the
level will rise exactly to the zero mark, and denote that the bottle
has supported the test without any modification of its structure. But
if, on the contrary, the level does not return to the zero mark, the
limit of the glass's elasticity has been extended, its molecules have
taken on a new state of equilibrium, and its resistance has
diminished, and, even if it has not broken, it is absolutely certain
that it has lost its former resistance and that it presents no
particular guarantee of strength.

The vessel, A B, which must be always full of water, is designed to
keep the bottle at a constant temperature during the course of the
experiment. This is an essential condition, since the bottle thus
filled with water constitutes a genuine thermometer, of which _a b_ is
the graduated tube. It is therefore necessary to avoid attributing a
variation in level due to an expansion of the water produced by a
change in temperature, to a deformation of the bottle.

The test, then, that can be made with bottles by means of the
elasticimeter consists in compressing them to a pressure of ten
atmospheres when filled with water at a temperature of 25°, and in
finding out whether, under such a stress, they change their volume
permanently. In order that the elasticimeter may not be complicated by
a special heating apparatus, it suffices to determine once for all
what the pressure is that, at a mean temperature of 15°, acts upon
bottles with the same energy as that of ten atmospheres at 25°.
Experiment has demonstrated that such stress corresponds to twelve
atmospheres in a space in which the temperature remains about 15°.

In addition, the elasticimeter is capable of giving other and no less
useful data. It permits of comparing the resistance of bottles and of
classifying them according to the degree of such resistance. After
numerous experiments, it has been found that first class bottles
easily support a pressure of twelve atmospheres without distortion,
while in those of an inferior quality the resistance is very variable.
The champagne wine industry should therefore use the former
exclusively.

Various precautions must be taken in the use of corks. The bottles
that lose their wine in consequence of the bad quality of their corks
are many in number, and it is not long since that they were the cause
of genuine disaster to the champagne trade.

Mr. Salleron has largely contributed to the improving of the quality
of corks found in the market. The physical and chemical composition of
cork bark is peculiarly favorable to the special use to which it is
applied; but the champagne wine industry requires of it an exaggerated
degree of resistance, inalterability, and elasticity. A 1¼ inch cork
must, under the action of a powerful machine, enter a ¾ inch neck,
support the dissolving action of a liquid containing 12 per cent. of
alcohol compressed to at least five atmospheres, and, in a few years,
shoot out of the bottle and assume its pristine form and color. Out of
a hundred corks of good quality, not more than ten support such a
test.

In order to explain wherein resides the quality of cork, it is
necessary to refer to a chemical analysis of it. In cork bark there is
70 per cent. of suberine, which is soluble in alcohol and ether, and
is plastic, ductile, and malleable under the action of humid heat.
Mixed with suberine, cerine and resin give cork its insolubility and
inalterability. These substances are soluble in alcohol and ether, but
insoluble in water.

According to the origin of cork, the wax and resin exist in it in very
variable proportion. The more resinous kinds resist the dissolving
action of wine better than those that are but slightly resinous. The
latter soon become corroded and spoiled by wine. An attempt has often
been made, but without success, to improve poor corks by impregnating
them with the resinous principle that they lack.

Various other processes have been tried without success, and so it
finally became necessary simply to separate the good from the bad
corks by a practical and rapid operation. A simple examination does
not suffice. Mr. Bouché has found that corks immersed in water finally
became covered with brown spots, and, by analogy, in order to test
corks, he immersed them in water for a fortnight or a month. All those
that came out spotted were rejected. Under the prolonged action of
moisture, the suberine becomes soft, and, if it is not resinous
enough, the cells of the external layer of the cork burst, the water
enters, and the cork becomes spotted.

It was left to Mr. Salleron to render the method of testing practical.
He compresses the cork in a very strong reservoir filled with water
under a pressure of from four to five atmospheres. By this means, the
but slightly resinous cork is quickly dissolved, so that, after a few
hours' immersion, the bad corks come out spotted and channeled as if
they had been in the neck of a bottle for six months. On the contrary,
good corks resist the operation, and come out of the reservoir as
white and firm as they were when they were put into it.

[Illustration: Fig. 2.--SALLERON'S APPARATUS FOR TESTING CORKS.]

Fig. 2 gives a perspective view of Mr. Salleron's apparatus for
testing corks. A reservoir, A B, of tinned copper, capable of holding
100 corks, is provided with a cover firmly held in place by a clamp.
Into the cover is screwed a pressure gauge, M, which measures the
internal pressure of the apparatus.

A pump, P, sucks water from a vessel through the tubulure, _t'_, and
forces it through the tubulure, _t_, into the reservoir full of corks.
After being submitted to a pressure of five atmospheres in this
apparatus for a few hours, the corks are verified and then sorted out.
In addition to the apparatus here illustrated, there is one of larger
dimensions for industrial applications. This differs from the other
only in the arrangement of its details, and will hold as many as
10,000 corks.--_Revue Industrielle._

       *       *       *       *       *




IMPROVED BISCUIT MACHINE.


The accompanying illustration represents a combined biscuit cutting,
scrapping, and panning machine, specially designed for running at high
speeds, and so arranged as to allow of the relative movements of the
various parts being adjusted while in motion. The cutters or dies,
mounted on a cross head working in a vertical guide frame, are
operated from the main shaft by eccentrics and vertical connecting
rods, as shown. These rods are connected to the lower strap of the
eccentric by long guide bolts, on which intermediate spiral springs
are mounted, and by this means, although the dies are brought quickly
down to the dough, they are suffered to remain in contact therewith,
under a gradually increasing pressure, for a sufficient length of time
to insure the dough being effectually stamped and completely cut
through.

[Illustration: IMPROVED BISCUIT MACHINE.]

Further, the springs tend to counteract any tendency to vibration that
might be set up by the rapid reciprocation of the cross head, cutters,
and their attendant parts. Mounted also on the main shaft is one of a
pair of reversed cone drums. These, with their accompanying belt and
its adjusting gear, worked by a hand wheel and traversing screw, as
shown, serve to adjust the speed of the feed rollers, so as to suit
the different lengths of the intermediate travel or "skip" of the
dough-carrying web.

Provision is made for taking up the slack of this belt by mounting the
spindle of the outer coned drum in bearings adjustable along a
circular path struck from the axis of the lower feed roller as a
center, thus insuring a uniform engagement between the teeth of the
small pinion and those of the spur wheel with which the drum and
roller are respectively provided.

The webs for carrying forward the dough between the different
operations pass round rollers, which are each operated by an
adjustable silent clutch feed, in place of the usual ratchet and pawl
mechanism. Movement is given to each feed by the connecting links
shown, to each of which motion is in turn imparted by the bell crank
lever placed beside the eccentric. This lever is actuated by a crank
pin on the main shaft, working into a block sliding in a slot in the
shorter or horizontal arm of the lever, while a similar but adjustable
block, sliding in the vertical arm, serves to impart the motion of the
lever to the system of connecting links, the adjustable block allowing
of a longer or shorter stroke being given to the different feeds, as
desired.

The scraps are carried over the roller in rear of the cutters, and so
to a scrap pan, while the stamped biscuits pass by a lower web into
the pans. These pans are carried by two endless chains, provided with
pins, which take hold of the pans and carry them along in the proper
position. The roller over which these chains pass is operated by a
silent clutch, and in order to give an additional motion to the chains
when a pan is full, and it is desired to bring the next pan into
position, an additional clutch is caused to operate upon the roller.
This clutch is kept out of gear with its pulley by means of a
projection upon it bearing against a disk slightly greater in diameter
than the pulley, and provided with two notches, into which the
projection passes when the additional feed is required.

The makers, H. Edwards & Co., Liverpool, have run one of these
machines easily and smoothly at a hundred revolutions per minute, at
which speed, and when absorbing about 3.5 horse power, the output
would equal 4,000 small biscuits per minute.--_Industries._

       *       *       *       *       *




IMPROVED CREAM SEPARATOR.


A hand separator of this type was exhibited at the Royal Show at
Newcastle by the Aylesbury Dairy Company, of 31 St. Petersburg Place,
Bayswater, England.

[Illustration: IMPROVED CREAM SEPARATOR. Fig. 1.]

[Illustration: IMPROVED CREAM SEPARATOR. Fig. 2.]

Fig. 1 is a perspective view of the machine, Fig. 2 being a vertical
section. The drums of these machines, which make 2,700 revolutions per
minute for the large and 4,000 for the small one, have a diameter of
27 in. and 15½ in. respectively, and are capable of extracting the
cream from 220 and 115 gallons of milk per hour. These drums are
formed by hydraulic pressure from one piece of sheet steel. To avoid
the possibility of the machines being overdriven, which might happen
through the negligence of the attendant or through the governing gear
on the engine failing to act, an ingenious controlling apparatus is
fixed to the intermediate motion of the separator as shown in Fig. 3.
This apparatus consists of a pair of governor balls pivoted near the
center of the arms and attached to the main shaft of the intermediate
gear by means of a collar fixed on it. The main shaft is bored out
sufficiently deep to admit a steel rod, against which bear the three
ends of the governor arms. The steel rod presses against the
counterbalance, which is made exactly the right weight to withstand
the force tending to raise it, when the intermediate motion is running
at its designed speed. The forks between which the belt runs are also
provided with a balance weight. This brings them to the loose pulley,
unless they are fixed by means of the ratchet. Should the number of
revolutions of the intermediate increase beyond the correct amount,
the extra centrifugal force imparted to the governor balls enables
them to overcome the balance weight, and in raising this they raise
the arm. This arm striking against the ratchet detent releases the
balance weight, and the belt is at once brought on to the loose
pulley.

[Illustration: IMPROVED CREAM SEPARATOR. Fig. 3.]

The steel drum is fitted with an internal ring at the bottom (see Fig.
2), into which the milk flows, and from which it is delivered, by
three apertures, to the periphery of the drum, thus preventing the
milk from striking against the cone of the drum, and from mixing with
the cream which has already been separated. The upper part of the drum
is fitted with an annular flange, about 1½ in. from the top, reaching
to within one-sixteenth of an inch of the periphery. After the
separation of the skim milk from the cream, the former passes behind
and above this flange through the aperture, B, and is removed by means
of the tube, D, furnished with a steel tip projecting from the cover
of the machine into the space between the top of the drum and the
annular flange, a similar tube, F, reaching below this flange,
removing the cream which collects there. The skim milk tube is
provided with a screw regulator, the function of which is to enable
cream of any desired consistency to be obtained, varying with the
distance between the skim milk and cream points from the center of the
drum. Another point about these tubes is their use as elevating tubes
for the skim, milk and cream, as, owing to the velocity at which the
drum is rotating, the products can be delivered by these tubes at a
height of 8 or 10 feet above the machine if required, thus enabling
scalding and cooling of either to be carried on while the separator is
at work, and saving hand labor.--_Iron._

       *       *       *       *       *




GAS FROM OIL.


At the twenty-fourth annual meeting of the Gas Institute, which was
recently held in Glasgow, Dr. Stevenson Macadam, F.R.S.E., lecturer on
chemistry, Edinburgh, submitted the first paper, which was on "Gas
from Oil."

He said that during the last seventeen years he had devoted much
attention to the photogenic or illuminating values of different
qualities of paraffin oils in various lamps, and to the production of
permanent illuminating gas from such oils. The earlier experiments
were directed to the employment of paraffin oils as oils, and the
results proved the great superiority of the paraffin oils as
illuminating agents over vegetable and animal oils, alike for
lighthouse and ordinary house service.

The later trials were mainly concerned with the breaking up of the
paraffin oils into permanent illuminating gas. Experiments were made
at low heats, medium heats, and high heats, which proved that,
according to the respective qualities of the paraffin oils employed in
the trials, there was more or less tendency at the lower heats to
distill oil instead of permanent gas, while at the high heats there
was a liability to decarbonize the oil and gas, and to obtain a thin
gas of comparatively small illuminating power. When, however, a good
cherry red heat was maintained, the oils split up in large proportion
into permanent gas of high illuminating quality, accompanied by little
tarry matter, and with only a slight amount of separated carbon or
deposited soot.

The best mode of splitting up the paraffin oils, and the special
arrangements of the retort or distilling apparatus, also formed, he
said, an extensive inquiry by itself. In one set of trials the oil was
distilled into gaseous vapor, and then passed through the retort. In
another set of experiments, the oil was run into or allowed to trickle
into the retorts, while both modes of introducing the oil were tried
in retorts charged with red hot coke and in retorts free from coke.

Ultimately, it was found that the best results were obtained by the
more simple arrangement of employing iron retorts at a good cherry red
heat, and running in the oil as a thin stream direct into the retort,
so that it quickly impinged upon the red hot metal, and without the
intervention of any coke or other matter in the retorts. The paraffin
oils employed in the investigations were principally: (1) Crude
paraffin oil, being the oil obtained direct from the destructive
distillation of shale in retorts; (2) green paraffin oil, which is
yielded by distilling or re-running the crude paraffin oil, and
removing the lighter or more inflammable portion by fractional
distillation; and (3) blue paraffin oil, which is obtained by
rectifying the twice run oil with sulphuric acid and soda, and
distilling off the paraffin spirit, burning oil, and intermediate oil,
and freezing out the solid paraffin as paraffin scale. The best
practical trials were obtained in Pintsch's apparatus and in Keith's
apparatus.

After describing both of these, Dr. Macadam went on to give in great
detail the results obtained in splitting up blue paraffin oil into gas
in each apparatus. He then said that these experimental results
demonstrated that Pintsch's apparatus yielded from the gallon of oil
in one case 90.70 cubic feet of gas of 62.50 candle power, and in the
second case 103.36 cubic feet of 59.15 candle gas, or an average of
97.03 cubic feet of 60.82 candle power gas.

In both cases, the firing of the retorts was moderate, though in the
second trial greater care was taken to secure uniformity of heat, and
the oil was run in more slowly, so that there was more thorough
splitting up of the oil into permanent gas. The gas obtained in the
two trials was of high quality, owing to its containing a large
percentage of heavy hydrocarbons, of which there were, respectively,
39.25 and 37.15 per cent., or an average of 38.2 per cent., while the
sulphureted hydrogen was nothing, and the carbonic acid a mere trace.
Besides testing the gas on the occasion of the actual trials, he had
also examined samples of the gas which he had taken from various
cylinders in which the gas had been stored for several months under a
pressure of ten atmospheres, and in all cases the gas was found to be
practically equal to the quantity mentioned, and hence of a permanent
character.

By using Keith's apparatus the results obtained were generally the
same, with the exception that an average of 0.27 per cent. of carbonic
acid gas and decided proportions of sulphureted hydrogen were found to
be present in the gas. Dr. Macadam devoted some remarks to the
consideration of the question as to how far the gas obtained from the
paraffin oil represented the light power of the oil itself, and then
he proceeded to say that, taking the crude paraffin oil at 2d. a
gallon, and with a specific gravity of 850 (water = 1,000), or 8½ lb.
to the gallon, there were 264 gallons to the ton, at a cost of £2 4s.
per ton. The sperm light from the ton of oil as gas being 3,443 lb.,
he reckoned that fully 6 lb. of sperm light were obtained from a
pennyworth of the crude oil as gas.

Then, taking the blue paraffin oil at 4d. per gallon, and there being
255 gallons to the ton, it was found that the cost of one ton was £4
5s., and as the sperm light of a ton of that oil as gas was 5,150 lb.,
it was calculated that 5 lb. of sperm light were yielded in the gas
from a pennyworth of the blue oil. The very rich character of the oil
gas rendered it unsuitable for consumption at ordinary gas jets,
though it burned readily and satisfactorily at small burners not
larger than No. 1 jets.

In practical use it would be advisable to reduce the quality by
admixture with thin and feeble gas, or to employ the oil gas simply
for enriching inferior gases derived from the more common coals. On
the question of dilution, he said that he preferred to use carbonic
oxide and hydrogen, and most of the remainder of his paper was devoted
to an explanation of the best mode of preparing those gases (water
gases).

He concluded by saying: The employment of paraffin oil for gas making
has advantages in its favor, in the readiness of charging the retorts,
as the oil can be run in continuously for days at a time, and may be
discontinued and commenced again without opening, clearing out
residual products, recharging and reclosing the retorts. There is
necessarily, therefore, less labor and cost in working, and as the gas
is cleaner or freer from impurities, purifying plant and material will
be correspondingly less. Oil gas is now employed for lighthouse
service in the illumination of the lanterns on Ailsa Craig and as
motive power in the gas engines connected with the fog horns at
Langness and Ailsa Craig lighthouse stations. It is also used largely
in the lighting of railway carriages. Various populous places are now
introducing oil gas for house service, and he felt sure that the
system is one which ought to commend itself for its future development
to the careful consideration and practical skill of the members of the
Gas Institute.

       *       *       *       *       *




THE MANUFACTURE OF SALT NEAR MIDDLESBROUGH.[1]

  [Footnote 1: Abstract of paper read before the Institution of
               Civil Engineers, May 17, 1887.]

By Sir LOWTHIAN BELL, Bart., F.R.S.


The geology of the Middlesbrough salt region was first referred to,
and it was stated that the development of the salt industry in that
district was the result of accident. In 1859, Messrs. Bolckow &
Vaughan sank a deep well at Middlesbrough, in the hope of obtaining
water for steam and other purposes in connection with their iron works
in that town, although they had previously been informed of the
probably unsuitable character of the water if found. The bore hole was
put down to a depth of 1,200 feet, when a bed of salt rock was struck,
which proved to have a thickness of about 100 feet. At that time
one-eighth of the total salt production of Cheshire was being brought
to the Tyne for the chemical works on that river, hence the discovery
of salt instead of water was regarded by some as the reverse of a
disappointment. The mode of reaching the salt rock by an ordinary
shaft, however, failed, from the influx of water being too great, and
nothing more was heard of Middlesbrough salt until a dozen years
later, when Messrs. Bell Brothers, of Port Clarence, decided to try
the practicability of raising the salt by a method detailed in the
paper. A site was selected 1,314 yards distant from the well of
Messrs. Bolckow & Vaughan, and the Diamond Rock Boring Company was
intrusted with the work of putting down a hole in order to ascertain
whether the bed of salt extended under their land. This occupied
nearly two years, when the salt, 65 feet in thickness, was reached at
a depth of 1,127 feet. Other reasons induced the owners of the
Clarence iron works to continue the bore hole for 150 feet below the
bed of salt; a depth of 1,342 feet from the surface was then reached.
During the process of boring, considerable quantities of inflammable
gas were met with, which, on the application of flame, took fire at
the surface of the water in the bore hole. The origin of this gas, in
connection with the coal measures underlying the magnesian limestone,
will probably hereafter be investigated.

For raising the salt, recourse was had to the method of solution, the
principle being that a column of descending water should raise the
brine nearly as far as the differences of specific gravity between the
two liquids permitted--in the present case about 997 feet. In other
words, a column of fresh water of 1,200 feet brought the brine to
within 203 feet of the surface. For the practical application of this
system a hole of say 12 inches in diameter at the surface was
commenced, and a succession of wrought iron tubes put down as the
boring proceeded, the pipes being of gradually decreasing diameter,
until the bottom of the salt bed was reached. The portion of this
outer or retaining tube, where it passed through the bed of salt, was
pierced with two sets of apertures, the upper edge of the higher set
coinciding with the top of the seam, and the other set occupying the
lower portion of the tube. Within the tube so arranged, and secured at
its lower extremity by means of a cavity sunk in the limestone, a
second tube was lowered, having an outer diameter from two to four
inches less than the interior diameter of the first tube. The latter
served for pumping the brine. The pump used was of the ordinary bucket
and clack type, but, in addition, at the surface, there was a plunger,
which served to force the brine into an air vessel for the purposes of
distribution. The bucket and clack were placed some feet below the
point to which the brine was raised by the column of fresh water
descending in the annulus formed between the two tubes. In commencing
work, water was let down the annulus until the cavity formed in the
salt became sufficiently large to admit of a few hours' pumping of
concentrated brine. On the machinery being set in motion, the stronger
brine was first drawn, which, from its greater specific gravity,
occupied the lower portion of the cavity. As the brine was raised,
fresh water flowed down. The solvent power of the newly admitted water
was of course greater than that of water partially saturated, and
being also lighter it occupied the upper portion of the excavated
space. The combined effect was to give the cavity the form of an
inverted cone. The mode of extraction thus possessed the disadvantage
of removing the greatest quantity of the mineral where it was most
wanted for supporting the roof, and had given rise to occasional
accidents to the pipes underground. These were referred to in detail,
and the question was started as to possible legal complications
arising hereafter from new bore holes put down in close proximity to
the dividing line of different properties, the pumping of brine formed
under the conditions described presenting an altogether different
aspect from the pumping of water or natural brine.

The second part of the paper referred to the uses to which the brine
was applied, the chief one being the manufacture of common salt. For
this purpose the brine, as delivered from the wells, was run into a
large reservoir, where any earthy matter held in suspension was
allowed to settle. The clear solution was then run into pans sixty
feet long by twenty feet wide by two feet deep. Heat was applied at
one end by the combustion of small coal, beyond which longitudinal
walls, serving to support the pan and to distribute the heat,
conducted the products of combustion to the further extremity, where
they escaped into the chimney at a temperature of from 500° to 700°
Fahr. On the surface of the heated brine, kept at 196° Fahr., minute
cubical crystals speedily formed. On the upper surface of these, other
small cubes of salt arranged themselves in such a way that, in course
of time, a hollow inverted pyramid of crystallized salt was formed.
This ultimately sank to the bottom, where other small crystals united
with it, so that the shape became frequently completely cubical. Every
second day the salt was "fished" out and laid on drainers to permit
the adhering brine to run back into the pans. For the production of
table salt the boiling was carried on much more rapidly, and at a
higher temperature than for salt intended for soda manufacture. The
crystals were very minute, and adhered together by the solidification
of the brine, effected by exposure on heated flues. For fishery
purposes the crystals were preferred very coarse in size. These were
obtained by evaporating the brine more slowly and at a still lower
temperature than when salt for soda makers was required. At the
Clarence works experiments had been made in utilizing surplus gas from
the adjacent blast furnaces, instead of fuel, under the evaporating
pans, the furnaces supplying more gas than was needed for heating air
and raising steam for iron making. By means of this waste heat, from
200 to 300 tons of salt per week were now obtained.

The paper concluded with some particulars of the soda industry. The
well-known sulphuric acid process of Leblanc had stood its ground for
three-quarters of a century in spite of several disadvantages, and
various modes of utilizing the by-products having been from time to
time introduced, it had until recent years seemed too firmly
established to fear any rivals. About seven years ago, however, Mr.
Solvay, of Brussels, revived in a practical form the ammonia process,
patented forty years ago by Messrs. Hemming & Dyar, but using brine
instead of salt, and thus avoiding the cost of evaporation. This
process consisted of forcing into the brine currents of carbonic acid
and ammoniacal gases in such proportions as to generate bicarbonate of
ammonia, which, reacting on the salt of the brine, gave bicarbonate of
soda and chloride of ammonium. The bicarbonate was placed in a
reverberatory furnace, where the heat drove off the water and one
equivalent of carbonic acid, leaving the alkali as monocarbonate. Near
Middlesbrough, the only branch of industry established in connection
with its salt trade was the manufacture of soda by an ammonia process,
invented by Mr. Schloesing, of Paris. The works were carried on in
connection with the Clarence salt works. It was believed that the
total quantity of dry soda produced by the two ammonia processes,
Solvay's and Schloesing's, in this country was something under 100,000
tons per annum, but this make was considerably exceeded on the
Continent.

       *       *       *       *       *




COTTON INDUSTRIES OF JAPAN.


The cotton plant principally cultivated in Japan is of the species
known as _Gossypium herbaceum_, resembling that of India, China, and
Egypt. The plant is of short stature, seldom attaining a growth of
over two feet; the flower is deciduous, with yellow petals and purple
center, and the staple is short, but fine. It is very widely
cultivated in Japan, and is produced in thirty-seven out of the
forty-four prefectures forming the empire, but the best qualities and
largest quantities are grown in the southern maritime provinces of the
mainland and on the islands of Kiusiu and Shikoku. Vice consul
Longford, in his last report, says that the plant is not indigenous to
Japan, the seed having been first imported from China in the year
1558. There are now many varieties of the original species, and the
cultivation of the plant varies in its details in different
localities. The variations are, however, mostly in dates, and the
general grinding principles of the several operations are nearly the
same throughout the whole country. The land best suited for cotton
growing is one of a sandy soil, the admixture of earth and sand being
in the proportion of two parts earth to one of sand. During the winter
and spring months, crops of wheat or barley are raised on it, and it
is when these crops have attained their full height during the month
of May that the cotton is sown. About fifty days prior to the sowing a
manure is prepared consisting of chopped straw, straw ashes, green
grass, rice, bran, and earth from the bottom of the stagnant pools.
These ingredients are all carefully mixed together in equal
proportions, and the manure thus made is allowed to stand till
required for use. Ten days before the time fixed for sowing, narrow
trenches, about one inch in depth, are dug in the furrows, between the
rows of standing wheat or barleys and the manure is liberally
sprinkled along them by hand. For one night before sowing the seed is
steeped in water. It is then taken out, slightly mixed with straw
ashes, and sown in the trenches at intervals of a few inches. When
sown, it is covered with earth to the depth of half an inch, and
gently trampled down by foot. Four or five days after sowing, the buds
begin to appear above the earth, and almost simultaneously the wheat
or barley between which they grow is ripe for the sickle. While the
latter is being harvested, the cotton may be left to itself, but not
for very long. The buds appear in much larger numbers than the soil
could support if they were allowed to grow. They have accordingly to
be carefully thinned out, so that not more than five or six plants are
left in each foot of length. The next process is the sprinkling of a
manure composed of one part night soil and three parts water, and
again, subsequent to this, there are two further manurings; one of a
mixture of dried sardines, lees of oil, and lees of rice beer, which
is applied about the middle of June, when the plant has attained a
height of four inches; and again early in July, when the plant has
grown to a height of six or seven inches, a further manuring of night
soil, mixed with a larger proportion of water than before. At this
stage the head of the plant is pinched off with the fingers, in order
to check the excessive growth of the stem, and direct the strength
into the branches, which usually number five or six. From these
branches minor ones spring, but the latter are carefully pruned off as
they appear. In the middle of August the flowers begin to appear
gradually. They fall soon after their appearance, leaving in their
place the pod or peach (_momo_), which, after ripening, opens in
October by three or four valves and exposes the cotton to view. The
cotton is gathered in baskets, in which it is allowed to remain till a
bright, sunshiny day, when it is spread out on mats to dry and swell
in the sun for two or three days. After drying, the cotton is packed
in bags made of straw matting, and either sold or put aside until such
time as the farmer's leisure from other agricultural operations
enables him to deal with it. The average yield of cotton in good
districts in Japan is about 120 lb. to the acre, but as cotton is only
a secondary crop, this does not therefore represent the whole profit
gained by the farmer from his land. The prefectures in which the
production is largest are Aichi on the east coast, Osaka, Hiogo,
Hiroshima, and Yamaguchi on the inland sea, and Fukui and Ishikawa on
the west coast. Vice-consul Longford says that the manufacture of
cotton in Japan is still in all its stages largely a domestic one.
Gin, spindle, and loom are all found in the house of the farmer on
whose land the cotton is grown, and not only what is required for the
wants of his own family is spun and woven by the female members
thereof, but a surplus is also produced for sale.

Several spinning factories with important English machinery have been
established during the last twenty years, but Consul Longford says
that he has only known of one similar cotton-weaving factory, and that
has not been a successful experiment. Other so called weaving
factories throughout the country consist only of a collection of the
ordinary hand looms, to the number of forty or fifty, scarcely ever
reaching to one hundred, in one building or shed, wherein individual
manufacturers have their own special piece goods made.

The first operation in the manufacture is that of ginning, which is
conducted by means of a small implement called the _rokuro_, or
windlass. This consists of two wooden rollers revolving in opposite
directions, fixed on a frame about 12 inches high and 6 inches in
width, standing on a small platform, the dimensions of which slightly
exceed that of the frame. The operator, usually a woman, kneels on one
side of the frame, holding it firm by her weight, works the roller
with one hand, and with the other presses the cotton, which she takes
from a heap at her side, between the rollers. The cotton passes
through, falling in small lumps on the other side of the frame, while
the seeds fall on that nearest the woman. The utmost weight of
unginned cotton that one woman working an entire day of ten hours can
give is from 8 lb. to 10 lb., which gives, in the end, only a little
over 3 lb. weight of ginned cotton, and her daily earnings amount to
less than 2d. A few saw gins have been introduced into Japan during
the last fifteen years, but no effort has been made to secure their
distribution throughout the country districts. After ginning, a
certain proportion of the seed is reserved for the agricultural
requirements of the following year, and the remainder is sent to oil
factories, where it is pressed, and yields about one-eighth of its
capacity in measurement in oil, the refuse, after pressing, being used
for manure. The ginning having been finished in the country districts,
the cotton is either packed in bales and sent to the dealers in the
cities, or else the next process, that of carding, is at once
proceeded with on the spot.

This process is almost as primitive as that of the ginning. A long
bamboo, sufficiently thin to be flexible, is fastened at its base to a
pillar or the corner of a small room. It slopes upward into the center
of the room, and from its upper end a hempen cord is suspended. To
this is fastened the "bow," an instrument made of oak, about five feet
in length, two inches in circumference, and shaped like a ladle. A
string of coarse catgut is tightly stretched from end to end of the
bow, and this is beaten with a small mallet made of willow, bound at
the end with a ring of iron or brass. The raw cotton, in its coarse
state, is piled on the floor just underneath the string of the bow.
The string is then rapidly beaten with the mallet, and as it rises and
falls it catches the rough cotton, cuts it to the required degree of
fineness, removes impurities from it, and flings it to the side of the
operator, where it falls on a hempen net stretched over a four-cornered
wooden frame. The spaces of the net are about one-quarter of an inch
square, and through these any particles of dust that may still have
adhered to the cotton fall to the floor, leaving piled on top of the
net the pure cotton wool in its finished state. This work is always
performed by a man, and by assiduous toil throughout a long day, one
man can card from ten to twenty pounds weight of raw cotton. Payment is
made in proportion to the work done, and in the less remote country
districts is at the rate of about one penny for each pound carded. As
regards spinning and weaving, in the first of these branches of cotton
manufacture the Japanese have largely had recourse to the aid of
foreign machinery, but it is still to a much greater extent a domestic
industry, or at best carried on like weaving in the establishments of
cotton traders, in which a number of workers, varying from 20 to 100 or
more, each with his own spinning wheel, are collected together. Consul
Longford says the spinning wheel used in Japan differs in no respect
from that used in the country 300 years ago or (except that bamboo
forms an integral part of the materials of which it is made) from that
used in England prior to the invention of the jenny. The cost of one of
the wheels is about 9d., it will last for five or six years, and with
it a woman of ordinary skill can spin about 1 lb. of yarn in a day of
ten hours, earning thereby about 2d. There are at present in various
parts of Japan, in all, 21 spinning factories worked by foreign
machinery. Of four of these there is no information, but of the
remainder, one has 120 spindles; eleven, 2,000 spindles; two, 3,000
spindles; two, 4,000 spindles; and one, 18,000 spindles.--_Journal Soc.
of Arts._

       *       *       *       *       *

[Continued from SUPPLEMENT, No. 612, page 9774.]




CENTRIFUGAL EXTRACTORS.

By ROBERT F. GIBSON.


SUGAR MACHINES.--Besides separating the crystalline sugar and the
sirup, secondary objects are to wash the crystals and to pack them in
cakes. The cleansing fluid or "white liquor" is introduced at the
center of the basket and is hurled against and passes through the sugar
wall left from draining. The basket may be divided into compartments
and the liquor guided into each. The compartments are removable boxes
and are shaped to give bars or cakes or any form desired of sugar in
mass. These boxes being removable cannot fit tightly against the liquor
guides, and the liquor is apt to escape. This difficulty is overcome by
giving the guides radial movement or by having rubber packing around
the edges.

Sugar machines proper are of two kinds--those which are loaded, drained
and then unloaded and those which are continuous in their working. The
various figures preceding are of the first kind, and what has been said
of vibrations applies directly to these.

The general advantages claimed for continuous working over intermittent
are--that saving is made of time and motive power incident to
introducing charge and developing velocity, in retarding and stopping,
and in discharging; that, as the power is brought into the machine
continuously, no shifting of belts or ungearing is necessary; and that
there are less of the dangers incident to variable motion, either in
the machine itself or the belting or gearing. The magma (the mixture of
crystalline sugar and sirup) is fed in gradually, by which means it is
more likely to assume a position of equilibrium in the basket.

There are two methods of discharging in continuous working--the sugar
is thrown out periodically as the basket fills, or continuously. In
neither case is the speed slackened. In the first either the upper
half of the basket has an upward motion, on the lower half a downward
motion (Pat. 252,483); and through the opening thus made the sugar is
thrown. Fig. 22 (R.B. Palmer & Sons) is a machine of this kind. The
bottom, B, with the cone distributor, _a_, have downward motion.

[Illustration: Fig. 22.]

Continuous discharge of the second kind may be brought about by having
a scoop fixed to the curb (or casing), extending down into the basket
and delivering the sugar over the side (Pat. 144,319). Another method
will be described under "Beet Machines."

BASKET.--The construction of the basket is exceedingly important. Hard
experience has taught this. When centrifugals were first introduced,
users were compelled by law to put them below ground; for they
frequently exploded, owing to the speed being suddenly augmented by
inequalities in the running of the engine or to the basket being too
weak to resist the centrifugal force of the overcharge. Increasing the
thickness merely adds to the centrifugal force, and hence to the
danger, as even a perfectly balanced basket may sever.

One plan for a better basket was to have more than one wall. For
example, there might be an inner wall of perforated copper, then one
of wire gauze, and then another of copper with larger perforations.
Another plan was to have an internal metallic cloth, bearing against
the internally projecting ridges of the corrugations of the basket
wall. A further complication is to give this internal gauze cylinder a
rotation relative to the basket.

The basket wall has been variously constructed. In one case it
consists of wire wound round and round and fastened to uprights,
commonly known as the "wire basket;" in another case of a periphery
without perforations, but spirally corrugated and having an opening at
the bottom for the escape of the extracted liquid; in still another of
a series of narrow bars or rings, placed edgewise, packed as close as
desired. An advantage of this last style is that it is easily cleaned.

The best basket consists of sheet metal with bored perforations and
having bands or flanges sprung on around the outside. The metal is
brass, if it is apt to be corroded; if not, sheet iron. The
perforations may be round, or horizontally much longer than wide
vertically. One method for the manufacture of the basket wall (Pat.
149,553) is to roll down a plate, having round perforations, to the
required thickness, causing narrowing and elongation of the holes and
at the same time hardening the plate by compacting its texture. Long
narrow slots are well adapted to catch sugar crystals, and this is not
an unimportant point. Round perforations are usually countersunk.
Instead of flanges, wire bands have been used, their lapping ends
secured by solder.

As to comparative wear, it maybe remarked that one perforated basket
will outlast three wire ones.

As to size, sugar baskets vary from 80 inches in diameter by 14 in.
depth to 54 by 24. They are made, however, in England as large as 6
feet in diameter--a size which can be run only at a comparatively slow
speed.

A peculiar complication of basket deserves notice (Pat. 275 874). It
had been noticed that when a charge of magma was put into a
centrifugal in one mass, the sugar wall on the side of the basket was
apt to form irregularly, too thick at base and of varied color. To
remedy this it was suggested to have within and concentric with the
basket a charger with flaring sides, into which the mixture was to be
put. When this charger reached a certain rotary velocity, the magma
would be hurled out over the edge by centrifugal force and evenly
distributed on the wall of the main basket.

SPINDLE.--The spindle as now made is solid cast steel, and the
considerations governing its size, form, material, etc., are identical
with those for any spindle. In order that the basket might be replaced
by another after draining, the shaft has been made telescopic, but at
the expense of stability and rigidity. In Fig. 16 is shown a device to
avoid crystallizations, which are apt to occur in large forgings, and
would prove fatal should they creep into the upper part of the spindle
proper in a hanging machine. It consists of the secondary spindle, _c_.

DISCHARGING.--The drained sugar may either be lifted over the top of
the basket (in machines which stop to be emptied), or be cast through
openings in the bottom provided with valves. A section of the best form
of valve may be seen in Figs. 15 and 17. Fig. 23 is a plan of the
openings. The valve turns on the basket bearing. It may be constructed
to open in the same direction in which the basket turns; so that when
the brake is put on, the inertia of the valve operates to open it and
while running to keep it closed. There are many other styles, but no
other need be mentioned.

[Illustration: Fig. 23.]

CASING.--The different styles of casing may be seen by reference to the
various drawings. In one machine (not described) the casing is rigidly
fixed to the basket, space enough being left between the bottom of the
basket and the bottom of the casing to hold all the molasses from a
charge. This arrangement merely adds to the bulk of the revolving
parts, and no real advantage is gained.

BEARINGS.--The various styles of bearings can be seen by reference to
the figures. One which deserves special attention is shown in Fig. 16
and Fig. 19. In one case it consists of loose disks, in the other of
loose washers, rotating on one another. They are alternately of steel
and hard bronze (copper and tin).

"There is probably no machine so little understood or so imperfectly
constructed by the common manufacturer of sugar supplies as the high
speed separator or centrifugal." Unless the product of experience and
good workmanship, it is a dangerous thing at high velocities. Besides,
its usual fate is to have an incompetent workman assigned to it, who
does not use judgment in charging and running. So that designers and
manufacturers have been forced not only to take into account the
disturbing forces inherent in revolving bodies, but also to make
allowance for poor management in running and neglect in cleaning.

CANE AND BEET MACHINES.--The first step in the process of sugar making
is the extraction of the juice from the beet or cane. This juice is
obtained by pressure. The operation is not usually, but may be,
performed in a special kind of centrifugal. One style (Pat. 239,222)
consists of a conical basket with a spiral flange within on the shaft,
and turning on the shaft, and having a slight rotary motion relative to
the basket. The material is fed in and moves downward under increased
pressure, the sirup released flying out through the perforations of the
basket, the whole revolving at high velocity. The solid portion falls
out at the bottom. Another plan suggested (Pat. 343,932) is to let a
loose cover of an ordinary cylindrical basket screw itself down into
the basket, by reason of its slower velocity (owing to inertia),
causing pressure on the charge.

Various other applications of the different styles of sugar machines
are the defibration of raw sugar juice, freeing beet crystals of
objectionable salts, freeing various crystals of the mother liquor,
drying saltpeter.

DRIERS.--Another important division of this first class of centrifugals
is that of driers or, as they are variously styled, whizzers, wringers,
hydro-extractors. The charge in these is never large in weight compared
to a sugar charge, and its initial distribution can be made more
symmetrical. The uses of driers are various, such as extracting water
from clothes, cloth, silk, yarns, etc. Water may be introduced at the
center of the basket from above or below to wash the material before
draining. A typical form of drier is shown in Fig. 24. (Pat. Aug. 22,
1876--W.P. Uhlinger.) Baskets have been made removable for use in
dyeing establishments, basket and load together going into dyeing vat.
Yarn and similar material can be drained by a method analogous to that
of hanging it upon sticks in a room and allowing the water to drip off.
It is suspended from short sticks, which are held in horizontal layers
around the shaft in the basket, and the action is such during the
operation as to cause the yarn to stand out in radial lines.

[Illustration: Fig. 24.]

Driers are not materially different from sugar machines. Any of the
devices before enumerated for meeting vibrations in the latter may be
applied to the former. There is one curious invention which has been
applied to driers only (Pat. 322,762--W.H. Tolhurst). See Fig. 25. A
convex shaft-supporting step resting on a concave supporting base,
with the center of its arc of concavity at the center of the upper
universal joint, has been employed, and its movements controlled by
springs, but the step was apt to be forced from its support. The
drawing shows the improvement on this, which is to give the
shaft-supporting step a less radius of curvature.

[Illustration: Fig. 25.]

An interesting form of drier has its own motor, a little steam engine,
attached to the frame of the machine. See Fig 24. This of course
demands fixed bearings. The engine is very small. One size used is 3"×4".
When a higher velocity of basket is required, we have the arrangement
in Fig. 26.

[Illustration: Fig. 26.]

MOTORS.--This naturally introduces the subject of motive power. We may
have the engine direct acting as above, or the power may be brought on
by belting. Fig. 27 shows a drier with pulley for belting. Fig. 28
(W.H. Tolhurst) shows a very common arrangement of belting and also the
fast and loose pulleys. When the heaviest part of the engine is so far
from the vertical shaft as to overhang the casing on one side, there is
apt to be an objectionable tremor. To remedy this, it is suggested to
put these heavy parts as near the shaft as possible. It has been
suggested also to use the Westinghouse type of engine, although the
type shown in Fig. 24 works faultlessly in practice.

[Illustration: Fig. 27.]

One plan (Pat. 346,030), designed to combine the advantages of a direct
acting motor and an oscillating shaft, mounts the whole machine, motor
and all, on a rocking frame. The spindle is of course in fixed bearings
in the frame. However, the plan is not practical.

[Illustration: Fig. 28.]

In driers the direct acting engine has many advantages over the belt.
The atmosphere is always very moist about a whizzer, and there are
frequently injurious fumes. The belt will be alternately dry and wet,
stretched and limp, and wears out rapidly and is liable to sever. In
all machines in which the shaft oscillates, if the center of
oscillation does not lie in the central plane of the belt, the tension
of the latter is not uniform. This affects badly both the belt and the
running. A reference to the various figures will show the best position
for the pulley.

The greatest difficulty experienced with belting is in getting up speed
and stopping. The basket must not be started with a sudden impulse. Its
inertia will resist and something must give way. A gradual starting can
be obtained by the slipping of the belt at first, but this is
expensive. The best plan is to conduct the power through a species of
friction clutch--an iron disk between two wooden ones. This has been
found to work admirably.

BRAKES.--The first centrifugals had no brakes. They ran until the
friction of the bearings was sufficient to stop them. This occasioned,
however, rapid wearing and too great a loss of time. The best material
for a brake consists of soft wood into which shoe pegs have been
driven, and which is thoroughly saturated with oil. The wooden disks
referred to just above are of the same construction. The center of
oscillation ought to be in the central plane of the brake as well as
that of the pulley, but the preference is given to the pulley.

Figs. 15 and 16 (I) give sectional views of a brake for hanging
machines. Figs. 19, 20, and 21 give two sections and a view of a brake
which can be used on both hanging and standing machines. A very simple
form of brake is shown in Figs. 24, 26, and 27 (A), a mere block
pressing on the rim of the basket.

OIL AND FAT.--A machine in most respects like a whizzer is used for the
"extraction of oil and fat and oily and fatty matters from woolen yarns
and fabrics, and such other fibrous material or mixtures of materials
as are from their nature affected in color or quality when hydrocarbons
are used for the purpose of extracting such oily or fatty matters, and
are subsequently removed from the material under treatment by the slow
process of admitting steam, or using other means of raising the
temperature to the respective boiling points of such hydrocarbons, and
so driving them off by evaporation." In the centrifugal method
carbon-bisulphide, or some other volatile agent, is admitted and is
driven through the material by centrifugal force, when the necessary
reactions take place, and is allowed to escape in the form of
hydrocarbons. A machine differing only in slight particulars from the
above is used for cleansing wool.

LOOSE FIBER.--Another application is the drying of loose fiber. Two
distinctive points deserve to be noticed in the centrifugal used for
this purpose. An endless chain or belt provided with blades moves the
material vertically in the basket, and discharges it over the edge.
During its upward course the material is subjected to a shower of water
to wash it.

OIL FROM METAL CHIPS.--Very material savings are made in many factories
by collecting the metal chips and turnings, coated and mixed with oil,
which fall from the various machines, and extracting the oil
centrifugally. The separator consists of a chip holder, having an
imperforate shell flaring upward and outward from the spindle (in fixed
bearings) to which it is attached. When filled, a cover is placed upon
it and keyed to the spindle. Between the cover and holder there is a
small annular opening through which oil, but not chips, can escape.
Fig. 29 (Pat. 225,949--C.F. Roper) is designed (like the greater part
of the drawings inserted) to show relative position of parts merely,
and not relative _size_. This style of machine can be used for sugar
separating (Pat. 345,994--F.P. Sherman) and many other purposes, to
which, however, there are other styles more especially adapted.

[Illustration: Fig. 29.]

FILTERERS.--There are two distinct kinds of centrifugal filterers,
working on different principles. Petroleum separators (Pat. 217,063)
are of the first kind. They are in form in all respects like a sugar
machine. The flakes of paraffine, stearine, etc., which are to be
extracted, when chilled are very brittle and would be disintegrated
upon being hurled against a plain wire gauze and would escape. Even a
woven fabric presents too harsh a surface. It is necessary to have a
very elastic basket lining of wool, cotton, or other fibrous material.
The basket itself may be either wire or perforated, but must have a
perfectly smooth bottom.

As the pressure of the liquor upon the filtering medium per unit of
surface depends entirely upon its radial depth, mere tubes, connecting
a central inlet with an annular compartment, will serve the purpose
quite as well as a whole basket. In this style of machine (Pat. 10,457)
the filtering material constitutes a wall between two annular
compartments. The outer one is connected with a vacuum apparatus.

Filterers of the second kind work on the following principle: If a
cylinder be rapidly revolved in a liquid in which solid particles are
suspended, the liquid will be drawn into a like rotation and the heavy
particles will be thrown to the outer part of the receptacle. If a
perforated cylinder is used as stirrer, the purified liquid will escape
into it through the perforations and may be conducted away. The
impurities, likewise, after falling down the sides of the receptacle,
are carried off. The advantages of this method are that no filtering
material is needed and the filtering surface is never in contact with
anything but pure liquor.

Very fine sawdust is, to a considerable extent, employed in sugar
refineries as a filtering medium. By such use the sawdust becomes mixed
with sand, fine particles of cane, etc. As sawdust of such fineness is
expensive, it is desirable to purify it in order to reuse it. A
centrifugal (Pat. 353,775--J.V.V. Booraem) built on the following
principle is used for this purpose. It has been observed that by
rotating rather _slowly_ small particles of various substances in
water, the finer particles will be thrown outward and deposit near the
circumference of the vessel, while the heavier and coarser particles
will deposit nearer to or at the center, their centrifugal force not
being sufficient to carry them out. A mere rod, extending radially in
both directions, serves by its rotation to set the water in motion.

Another form of filter of this second kind (Pat. 148,513) has a
rotating imperforate basket into which the impure liquor is run. Within
and concentric with it is another cylinder whose walls are of some
filtering medium. The liquid already partly purified by centrifugal
force passes through into the inner cylinder, thus becoming further
purified. Centrifugal filters are used also to cleanse gums for
varnishes.

HONEY.--The simplest form of honey extractor (Pat. 61,216) consists of
a square framework, symmetrical with respect to a vertical spindle.
This framework is surrounded by a wire gauze. The combs, after having
the heads of the cells cut off, are placed in comb-holders against the
wire netting on the four sides, the cells pointing outward. The machine
is turned by hand. The honey is hurled against the walls of a receiving
case and caught below. But few improvements have been made on this. The
latest machines are still hand-driven, as a sufficiently high velocity
can be obtained in this manner. In one style the combs are placed upon
a floor which rests upon springs. The rotating box is given a slight
vertical and horizontal reciprocatory motion, by which the combs are
made to grate on the wire gauze sides, breaking the cells and
liberating the honey. Thus the labor of cutting the cells is saved.
Every comb has two sides, and to present each side in succession to the
outside without removing from the basket, several devices have been
patented. In some the comb holders are hinged in the corners of the
basket, and have an angular motion of ninety degrees. Decreasing the
speed is sufficient to swing these. The other side is then emptied by
revolving in the opposite direction. In one case each holder has a
spindle of its own, connected with the main spindle by gearing and, to
present opposite side, turns through 180°. The usual number of sides
and hence of comb holders is four, but eight have been used. There are
minor differences in details of construction, looking to the most
convenient removal and insertion of comb, the reception of the
extracted honey in cups, buckets, etc., and the best method of giving
rapid rotation, which cannot be touched upon. The product of the
operation is white and opaque, but upon heating regains its golden
color and transparency.

STARCH.--A centrifugal to separate starch from triturated grain,
carried in suspension in water, is as follows. (Pat. 273,127--Müller &
Decastro.) The starch water is led to the bottom of a basket, and, as
starch is heavier than the gluten with which it is mixed, the former
will be immediately compacted against the periphery of the basket,
lodging first in the lower corner, the starch and gluten forming two
distinct strata. A tube with a cutting edge enters the compacted mass
so deeply as to peel off the gluten and part of the starch, which is
carried through the tube to another compartment of the basket, just
above, where the same operation is performed, and so on. There may be
only one compartment, the tube carrying the gluten directly out of the
machine. These machines are continuous working, and hence some way must
be devised to carry the water off. The inner surface of the water is,
as we have seen, a cylinder. When the diameter of this cylinder becomes
too small, overflow must be allowed. One plan is to have an overflow
opening made in the bottom of the basket in such a way that as the
starch wall thickens, the opening recedes toward the center. The starch
wall is either lifted out in cakes or put again in suspension by
spraying water on it and conducting the mixture off.

A centrifugal (Pat. 74,021) to separate liquids from paints depends on
building a wall of paint on the sides of the basket and carrying the
liquids off at the center.

A centrifugal (Pat. 310,469) for assorting wood pulp, paper pulp, etc.,
works by massing the constituents in two or three cylindrical strata,
and after action severing and removing these separately.

BREWING.--In brewing, centrifugals are quite useful. After the wort has
been boiled with hops, albuminous matters are precipitated by the
tannic acid, which must be extracted. Besides these the mixture
frequently contains husk, fiber, and gluten. The machine (Pat.
315,876), although quite unique in construction, has the same principle
of working as a sugar centrifugal, and need not be described. There is
one point, however, which might be noticed--that air is introduced at
about the same point as the material, and has an oxidizing and
refrigerating effect.

Class I. includes also centrifugals for the following purposes: The
removal of must from the grape after crushing, making butter,
extracting oils from solid fats, separating the liquid and solid parts
of sewerage, drying hides, skins, spent tan and the like, drying coils
of wire.

HORIZONTAL CENTRIFUGALS.--Only vertical machines have been and will be
dealt with. Horizontal centrifugals, that is, those whose spindles are
horizontal have been made, but the great inconvenience of charging and
discharging connected with them has occasioned their disuse; though in
other respects for liquids they are quite as good as vertical
separators. Their underlying theory is practically the same as that
hereinbefore discussed.

CLASS II., CREAMERS.--Centrifugals of the second class separate liquids
from liquids. There are two main applications in this class--to
separate cream from milk and fusel oil from alcoholic liquors. When a
liquid is to be separated from a liquid, the receptacle must be
imperforate. The components of different specific gravity become
arranged in distinct concentric cylindrical strata in the basket, and
must be conducted away separately. In creamers the particles of cream
must not be broken or subjected to any concussion, as partial churning
is caused and the cream will, in consequence, sour more rapidly.

The chief cause of oscillations in machines of this class, where the
charge is liquid, is the waves which form on the inner surface. They
may be met by allowing a slight overflow over the inner edge of the rim
of the basket; or by having either horizontal partitions, or vertical,
radial ones, special cases of which will be noticed. Oscillations may
also be met in the same manner as in sugar machines, by allowing the
revolving parts to revolve about an axis through their common center of
gravity. (Pat. 360,342--J. Evans.)

The crudest form of creamer contains a number of bottles, with their
necks all directed toward the spindle, filled with milk. The necks, in
which the cream collects, are graduated to tell when the operation is
complete.

Many methods for introducing the milk into creamers have been devised.
It may run in from the top at the center, or emerge from a pipe at the
bottom of the basket; or the spindle may be hollow and the milk sucked
up through it from a basin below. It is usual to let the milk enter
under hydrostatic pressure (Pat. 239,900--D. M. Weston) and let the
force of expulsion of the cream be dependent on this pressure. This
renders the escape quiet, and prevents churning. Gravity, too, is made
effective in carrying the constituents off.

The cream may escape through a passage in the bottom at the center, and
the skim milk at the lower outer corner; or by ingeniously managed
passages both may escape at or near center. The rate of discharge can
be managed by regulating the size of opening of exit passages.

A curious method consists in having discharge pipes provided with
valves and floats at their lower ends, dipping into the liquid (Pat.
240,175). "The valves are opened and closed, or partially opened or
closed, by the floats attached to them, these floats being so
constructed and arranged with reference to their specific gravity and
the specific gravity of the component parts of the liquids operated
upon, that they will permit only a liquid of a determinate specific
gravity to escape through the pipes to which they are respectively
attached."

We may have tubes directed into the different strata with cutting
edges. (Pat. 288,782.) A remarkable fact noticed in their use is that
these edges wear as rapidly as if solids were cut instead of liquids.

The separated fluids may be received into recessed rings, having
discharge pipes, the proportionate quantity discharged being regulated
by the proximity of the discharge lips to the surface of the ring, and
the centrifugal force being availed of to project the liquids through
the discharge pipes.

There is a very simple device by which a very rapid circulation of the
liquid is brought about. (Pat. 358,587--C.A. Backstrom.) The basket has
radial vertical partitions, all but one having communicating holes,
alternately in upper and lower corners. The milk is delivered into the
basket on one side of this imperforate partition and must travel the
whole circuit of the basket through these communicating holes, until it
reaches the partition again, and then passes into a discharge pipe.
Thus during this long course every particle of cream escapes to the
center. As the holes are close to the walls of the basket, the cream
has not the undulatory motion of the milk, which would injure it. The
greater the number of partitions, the longer is the travel of the milk,
and the more rapid the circulation. Blades have been devised similar to
the above, having communicating passages extending the whole width of
the blade, but we see that here the cream would circulate with the
milk; which must not be allowed. Curved blades have been used, and
paddles and stirrers, to set the milk in motion, but to them the same
objection may be made.

[Illustration: Fig. 30]

Fig. 30 (Pat. 355,048--C.A. Backstrom) illustrates one of the latest
and best styles of creamers. The milk enters at C. The skim milk passes
into tube, T, and the cream goes to the center and passes out of the
openings in the bottom, _k^{l}_, _k^{2}_, and _k^{3}_, out of the slit,
k, and thence out through D^{5}. The skim milk moves through T,
becoming more thoroughly separated all the while, and at each of the
radial branch tubes, T^{1}, T^{2}, T^{3}, and T^{4}, some cream leaves
it and goes to the center, while it passes down out of slit, t^{3}, and
thence out of D^{6}.

Fig. 31 (Pat. 355,050--C.A. Backstrom) shows another very late style of
creamer. A pipe delivers the milk into P^{4}. Passing out of the tube
separation takes place, and cream falls down the center to P^{2} and
out of O^{3}. When the compartment under the first shelf becomes full
of the skim milk, the latter passes up through the slot, S, strikes a
radial partition, R, and its course is reversed. Here more cream
separates and passes to center and falls directly, and so on through
the whole series of annular compartments, until the top one, when the
skim milk enters tube T^{2} and passes out of O^{2}. By this operation
there are substantially repeated subjections of specified quantities of
milk to the action of centrifugal force, bringing about a thorough
separation. By changing the course of the milk in direction, its path
is made longer. This machine can run at much lower speed than many
other styles, and yet do the same work.

[Illustration: Fig. 31]

CLASS III., SOLIDS FROM SOLIDS.--As for grain machines, which are in
this class, it may be said that in centrifugal flour bolters, bran
cleaners, and middlings purifiers, though theoretically centrifugal
force plays an important part in their action, yet practically the real
separation is brought about by other agencies: in some by brushes which
rub the finer particles through wire netting as they rotate against it.

The principle exhibited in a separator of grains and seeds is very
neat. (Pat. 167,297.) See Fig. 32. That part of the machine with which
we have to do consists essentially of a horizontal revolving disk. The
mixed grains are cast on this disk, pass to the edge, and are hurled
off at a tangent. Suppose at A. Each particle is immediately acted on
by three forces. For all particles of the same size and having the same
velocity the resistance of the air may be taken the same, that is,
proportional to the area presented. The acceleration of gravity is the
same; but the inertia of the heavier grain is greater. The resultant of
the two conspiring forces R and (M_v_^{2})/2 varies, and is greater for
a heavier grain. Therefore, the paths described in the air will vary,
especially in length; and how this is utilized the drawing illustrates.

[Illustration: Fig. 32.]

ORE.--In ore machines there is one for pulverizing and separating coal
(Pat. 306,544), in which there is a breaker provided with helical
blades or paddles, partaking of rapid rotary motion within a stationary
cylinder of wire netting. The dust, constituting the valuable part of
the product, is hurled out as fast as formed. In this style of machine,
beaters are necessary not only for pulverizing, but to get up rotary
motion for generating centrifugal force. In the classes preceding, the
friction of the basket sufficed for this latter purpose; but here there
is no rotating basket and no definite charge. As the material falls
through the machine, separation takes place. Various kinds of ore may
be treated in the same manner.

An "ore concentrator" (Pat. 254,123), as it is called, consists of a
pan having rotary and oscillatory motions. Crushed ore is delivered
over the edge in water. The heavy particles of the metal are thrown by
centrifugal force against the rim of the pan, overcoming the force of
the water, which carries the sand and other impurities in toward the
center and away.

AMALGAMATORS.--The best ore centrifugal or separator is what is called
an "amalgamator." The last invention (Pat. 355,958, White) consists
essentially of a pan, a meridian section of which would give a curve
whose normal at any point is in the direction of the resultant of the
centrifugal force at that point and gravity. There is a cover to this
pan whose convexity almost fits the concavity of the pan, leaving a
space of about an inch between. Crushed ore with water is admitted at
the center between the cover and the pan, and is driven by centrifugal
force through a mass of mercury (which occupies part of this space
between the two) and out over the edge of the pan. The particles of
metal coming in contact with the mercury amalgamate, and as the speed
is regulated so that it is never great enough to hurl the mercury out,
nothing but sand, water, etc., escape. There have been many different
constructions devised, but this general principle runs through all. By
having annular flanges running down from the cover with openings placed
alternately, the mixture is compelled to follow a tortuous course, thus
giving time for all the gold or other metal to become amalgamated.
There are ridges in the pan, too, against which the amalgam lodges. It
is claimed for this machine that not a particle of the precious metal
is lost, and experiments seem to uphold the claim.

A machine for separating fine from coarse clay for porcelain or for
separating the finer quality of plumbago from the coarser for lead
pencils uses an imperforate basket, against the wall of which the
coarser part banks and catches under the rim. The finer part forms an
inner cylindrical stratum, but is allowed to spill over the edge of the
rim. The mixture is introduced at the bottom of the basket at the
center.

CLASS IV., GASES AND SOLIDS.--There is a very simple contrivance
illustrating machines of this class used to free air from dust or other
heavy solid impurities which may be in suspension. See Fig. 33. The air
enters the passage, B (if it has no considerable velocity of itself, it
must be forced in), forms a whirlpool in the conically shaped
receptable, A, and passes up out of the passage, D. The heavy particles
are thrown on the sides and collect there and fall through opening, C,
into some closed receiver.

[Illustration: Fig. 33]

CLASS V., GASES AND LIQUIDS.--The occluded gases in steel and other
metal castings, if not separated, render the castings more or less
porous. This separation is effected by subjecting the molten metal to
the action of centrifugal force under exclusion of air, producing not
only the most minute division of the particles, but also a vacuum, both
favorable conditions for obtaining a dense metal casting.

Most of the devices for drying steam come under this head. Such are
those in which the steam with the water in suspension is forced to take
a circular path, by which the water is hurled by centrifugal force
against the concave side of the passage and passes back to the water in
the boiler.

SPEED.--The centrifugal force of a revolving particle varies, as we
have seen, as the square of the angular velocity, so that the effort
has been to obtain as high a number of revolutions per minute as was
consistent with safety and with the principle of the machine. For
example, creamers which are small and light make 4,000 revolutions per
minute, though the latest styles run much more slowly. Driers and sugar
machines vary from 600 to 2,000, while on the other hand the necessity
of keeping the mercury from hurling off in an amalgamator prevents its
turning more rapidly than sixty or eighty times a minute.

However, speed in another sense, the speed with which the operation is
performed, is what especially characterizes centrifugal extractors. In
this particular a contrast between the old methods and the new is
impressive. Under the action of gravity, cream rises to the milk's
surface, but compare the hours necessary for this to the almost
instantaneous separation in a centrifugal creamer. The sugar
manufacturer trusted to gravity to drain the sirup from his crystals,
but the operation was long and at best imperfect. An average sugar
centrifugal will separate 600 pounds of magma perfectly in three
minutes. Gold quartz which formerly could not pay for its mining is now
making its owners' fortunes. It is boasted by a Southern company that
whereas they were by old methods making twenty-five _cents_ per ton of
gold quartz, they now by the use of the latest amalgamator make
twenty-five _dollars_. Centrifugal force, as applied in extractors, has
opened up new industries and enlarged old ones, has lowered prices and
added to our comforts, and centrifugal extractors may well command, as
they do, the admiration of all as wonderful examples of the way in
which this busy age economizes time.

       *       *       *       *       *




A NEW TYPE OF RAILWAY CAR.


[Illustration: Fig. 1.--CAR WITH LATERAL PASSAGEWAYS.]

Figs. 1 and 2 give a perspective view and plan of a new style of car
recently adopted by the Bone-Guelma Railroad Company, and which has
isolated compartments opening upon a lateral passageway. In this
arrangement, which is due to Mr. Desgranges, the lateral passageway
does not extend all along one side of the car, but passes through the
center of the latter and then runs along the opposite side so as to
form a letter S. The car consists in reality of two boxes connected
beneath the transverse passageway, but having a continuous roof and
flooring. The two ends are provided with platforms that are reached by
means of steps, and that permit one to enter the corresponding half of
the car or to pass on to the next. The length from end to end is 33
feet in the mixed cars, comprising two first-class and four
second-class compartments, and 32 feet in cars of the third class,
with six compartments. The width of the compartments is 5.6 and 5
feet, according to the class. The passageway is 28 inches in width in
the mixed cars, and 24 in those of the third class. The roof is so
arranged as to afford a circulation of cool air in the interior.

[Illustration: Fig. 2.--PLAN.]

The application of the zigzag passageway has the inconvenience of
slightly elongating the car, but it is advantageous to the passengers,
who can thus enjoy a view of the landscape on both sides of the
train.--_La Nature._

       *       *       *       *       *




FOUNDATIONS OF THE CENTRAL VIADUCT OF CLEVELAND, O.


The Central viaduct, now under construction in the city of Cleveland,
is probably the longest structure of the kind devoted entirely to
street traffic. The superstructure is in two distinct portions,
separated by a point of high ground. The main portion, extending
across the river valley from Hill street to Jennings avenue, is 2,840
feet long on the floor line, including the river bridge, a swing 233
feet in length; the other portion, crossing Walworth run from Davidson
street to Abbey street, is 1,093 feet long. Add to these the earthwork
and masonry approaches, 1,415 feet long, and we have a total length of
5,348 feet. The width of roadway is 40 feet, sidewalks 8 feet each.
The elevation of the roadway above the water level at the river
crossing is 102 feet. The superstructure is of wrought iron, mainly
trapezoidal trusses, varying in length from 45 feet to 150 feet. The
river piers are of first-class masonry, on pile and timber foundations.
The other supports of the viaduct are wrought iron trestles on masonry
piers, resting on broad concrete foundations. The pressure on the
material beneath the concrete, which is plastic blue clay of varying
degrees of stiffness mixed with fine sand, is about one ton per square
foot.

The Cuyahoga valley, which the viaduct crosses from bluff to bluff, is
composed mainly of blue clay to a depth of over 150 feet below the
river level. No attempt is made to carry the foundation to the rock.
White oak piles from 50 to 60 feet in length and 10 inches in diameter
at small end are driven for the bridge piers either side of the river
bed, and these are cut off with a circular saw 18 feet below the
surface of the water. Excavation by dredging was made to a depth of 3
feet below where the piles are cut off to allow for the rising of the
clay during the driving of the piles. The piles are spaced about 2
feet 5 inches each way, center to center. The grillage or platform
covering the piles consists of 14 courses of white oak timber, 12
inches by 12 inches, having a few pine timbers interspersed so as to
allow the mass to float during construction. The lower half of the
platform was built on shore, care being taken to keep the lower
surface of the mass of timber out of wind. The upper and lower
surfaces of each timber were dressed in a Daniels planer, and all
pieces in the same course were brought to a uniform thickness. The
timbers in adjacent courses are at right angles to each other. The
lower course is about 58 feet by 22 feet, the top course about 50 by
24 feet, thus allowing four steps of one foot each all around. The
first course of masonry is 48 feet by 21 feet 8 inches; the first
course of battered work is 41 feet 8½ inches by 16 feet 3 inches. Thus
the area of the platform on the piles is 1,856 square feet, and of the
first batter course of masonry 777.6 square feet, or in the ratio of
2.4 to 1. The height of the masonry is 78 feet above the timber, or
73½ feet above the water. The number of piles in each foundation is
312. The average load per pile is about 11 tons, and the estimated
pressure per square inch of the timber on the heads of the piles is
about 200 pounds.

To prevent the submersion of the lower courses of masonry during
construction, temporary sides of timber were drift-bolted to the
margin of the upper course of the timber platform, and carried high
enough to be above the surface of the water when the platform was sunk
to the head of the piles by the increasing weight of masonry.

The center pier is octagonal, and is built in the same general manner
as to foundations as the shore piers, but the piles are cut off 22
feet below water, and there are eighteen courses of timber in the
grillage. The diameter of the platform between parallel sides is 53
feet, while that of the lower course of battered masonry is but 37
feet. The areas are as 2,332 to 1,147, or as 2 to 1 nearly. The
pressure per square inch of timber on the heads of the piles is about
the same as stated above for the shore piers. The number of piles
under the center pier is 483.

The risks and delays by this method of constructing the foundations
were much less, and the cost also, than if an ordinary coffer dam had
been used. Also the total weight of the piers is much less, as that
portion below a point about two feet below the water adds nothing to
their weight.

The piles were driven with a Cram steam hammer weighing two tons, in a
frame weighing also two tons. The iron frame rests directly upon the
head of the pile and goes down with it. The fall of the hammer is
about 40 inches before striking the pile. The total penetration of the
piles into the clay averaged 27 feet. The settlement of the pile
during the final strokes of the hammer varied from one quarter to
three quarters of an inch per blow.

There are 122 masonry pedestals, of which eight are large and heavy,
carrying spans of considerable length. They will all be built upon
concrete beds, except a few near the river on the north side, where
piles are required.

The four abutments with their retaining walls are of first-class
rock-faced masonry. The footing courses are stepped out liberally, so
as to present an unusually large bottom surface. They rest on beds of
concrete 4 feet thick. The foundation pits are about 50 feet below the
top of the bluffs, and are in a material common to the Cleveland
plateau, a mixture of blue sand and clay, with some water. The
estimated load of masonry on the earth at the bottom of the concrete
is one and seven tenths tons to the square foot. Two of the large
abutments were completed last season. They show an average settlement
of three eighths of an inch since the lower footing courses were laid.

The facts and figures here given regarding the viaduct were kindly
furnished by the city civil engineer, C.G. Force, who has the work in
charge.--_Jour. Asso. of Eng. Societies._

       *       *       *       *       *


For sticking paper to zinc, use starch paste with which a little
Venice turpentine has been incorporated, or else use a dilute solution
of white gelatine or isinglass.

       *       *       *       *       *




CENTRIFUGAL PUMPS AT MARE ISLAND NAVY YARD, CALIFORNIA.[1]

  [Footnote 1: Built by the Southwark Foundry and Machine Company,
               of Philadelphia.]

By H.R. CORNELIUS.


In December, 1883, bids were asked for by the United States government
on pumping machinery, to remove the water from a dry dock for vessels
of large size.

The dimensions of the dock, which is situated on San Pablo Bay,
directly opposite the city of Vallejo, are as follows:

Five hundred and twenty-nine feet wide at its widest part, 36 feet
deep, with a capacity at mean tide of 9,000,000 gallons.

After receiving the contract, several different sizes of pumps were
considered, but the following dimensions were finally chosen: Two 42
inch centrifugal pumps, with runner 66 inches in diameter and
discharge pipes 42 inches, each driven direct by a vertical engine
with 28 inch diameter cylinder and 24 inch stroke.

These were completed and shipped in June, 1885, on nine cars,
constituting a special train, which arrived safely at its destination
in the short space of two weeks, and the pumps were there erected on
foundations prepared by the government.

From the "Report of the Chief of Bureau of Yards and Docks" I quote
the following account of the official tests:

     "The board appointed to make the test resolved to fill the
     dock to about the level that would attain in actual service
     with a naval ship of second rate in the dock, and the tide at
     a stage which would give the minimum pumping necessary to
     free the dock. The level of the 20th altar was considered as
     the proper point, and the water was admitted through two of
     the gates of the caisson until this level was reached; they
     were then closed. The contents of the dock at this point is
     5,963,921 gallons.

     "The trial was commenced and continued to completion without
     any interruption in a very satisfactory manner.

     "In the separate trials had of each pump, the average
     discharge per minute was taken of the whole process, and
     there was a singular uniformity throughout with equal piston
     speed of the engine.

     "It was to be expected, and in a measure realized, that
     during the first moments of the operations, when the level of
     the water in the dock was above the center of the runner of
     the pumps, that the discharge would be proportioned to the
     work done, where no effort was necessary to maintain a free
     and full flow through the suction pipes; but as the level
     passed lower and farther away from the center there was no
     apparent diminution of the flow, and no noticeable addition
     to the load imposed on the engine. The variation in piston
     speed, noted during the trial, was probably due to the
     variation of the boiler pressure, as it was difficult to
     preserve an equal pressure, as it rose in spite of great
     care, owing to the powerful draught and easy steaming
     qualities of the boilers.

     "After the trial of the second pump had been completed the
     dock was again filled through the caisson, and as both pumps
     were to be tried, the water was admitted to a level with the
     23d altar, containing 7,317,779 gallons, which was seven feet
     above the center of the pumps; this was in favor of the pumps
     for the reasons before stated. In this case all the boilers
     were used.

     "Everything moved most admirably, and the performance of
     these immense machines was almost startling. By watching the
     water in the dock it could be seen to lower bodily, and so
     rapidly that it could be detected by the eye without
     reference to any fixed point.

     "The well which communicates with the suction tunnel was
     open, and the water would rise and fall, full of rapid swirls
     and eddies, though far above the entrance of these tunnels.
     Through the man hole in the discharge culvert the issuance
     from the pipes could be seen, and its volume was beyond
     conception. It flowed rapidly through the culvert, and its
     outfall was a solid prism of water, the full size of the
     tunnel, projecting far into the river.

     "During a pumping period of 55 minutes, the dock had been
     emptied from the twenty-third to two inches above the sixth
     altar, containing 6,210,698 gallons, an average throughout of
     112,922 gallons per minute. At one time, when the revolutions
     were increased to 160 per minute, the discharge was 137,797
     gallons per minute. This is almost a river, and is hardly
     conceivable. After the pumps were stopped, on this occasion,
     tests were made with each in succession as to the power of
     the ejectors with which each is fitted to recharge the pumps.

     "The valves in the discharge pipe were closed and steam
     admitted to the ejector, the pump being still and no water in
     the gauge glass on the pump casing, which must be full before
     the pumps will work. The suction pipe of the ejector is only
     two and a half inches in diameter, the steam pipe one inch in
     diameter. To fully charge the pumps at this point required
     filling the pump casing and the suction pipe containing about
     2,000 gallons; this was accomplished in four minutes, and
     when the gauge glass was full the pump operated instantly and
     with certainty, discharging its full volume of water.

     "I went on several occasions down in the valve pits on the
     ladder of the casing, and to all accessible parts while in
     motion at its highest speed, and there was no undue
     vibration, only a uniform murmur of well-balanced parts, and
     the peculiar clash of water against the sides of the casing
     as its velocity was checked by the blank spaces in the
     runner.

     "The pumps are noisy while at work, due to the clashing of
     the water just mentioned, but it affords a means of detecting
     any faulty arrangements of the runner or unequal discharge
     from any of its openings. While moving at a uniform speed,
     this clashing has a tone whose pitch corresponds with that
     velocity of discharge, and if this tone is lacking in
     quality, or at all confused, there is want of equality of
     discharge through the various openings of the runner. To this
     part I gave close attention, and there was nothing that the
     ear could detect to indicate aught but the nicest adjustment.
     The bearings of the runners worked with great smoothness, and
     did not become at all heated. Through a simple, novel
     arrangement, these bearings are lubricated and kept cool.
     There is a constant circulation of water from the pumps by
     means of a small pipe, which completes a circuit to an
     annular in the bearings back to the discharge pipe while the
     pump is in motion, requiring no oil and making it seemingly
     impossible to heat these bearings.

     "The large cast steel valves placed in the embouchement of
     the casing, it was thought, might act to check the free
     discharge, and arrangements were provided for raising and
     keeping them open by a long lever key attached to their axes
     of revolution, but, to our great surprise, at the first gush
     from the pumps these valves, weighing nearly 1,500 pounds,
     were lifted into their recessed chambers, giving an
     unobstructed opening to the flow, and they floated on its
     surface unsupported, save by the swiftly flowing water,
     without a movement, while the pump was in operation.

     "The steam-actuated valves in the suction and discharge pipes
     worked very well, and the water cushion gave a slow, uniform
     motion, and without shock, either in opening or closing them.

     "The engines worked noiselessly, without shock or labor. At
     no time during the trial was the throttle valve open more
     than three-eighths of an inch.

     "The indicator cards taken at various intervals gave 796
     horse power, and the revolutions did not exceed 160 at any
     time, though it was estimated that 900 horse power and 210
     revolutions would be necessary to attain the requisite
     delivery. So that there is a large reserve of power available
     at any time.

     "The erection of this massive machinery has been admirably
     done. The parts, as sent from the shops of the contractor,
     have matched in all cases without interference here; and,
     when lowered into place, its final adjustment was then made
     without the use of chisel or file, and has never been touched
     since.

     "The joints of the steam and water connections were perfect,
     and the method of concentrating all valves, waste pipes, and
     important movements at the post of the engineer in charge
     gives him complete control of the whole system of each engine
     and pump without leaving his place, and reduces to a minimum
     the necessary attendance. All the parts are strong and of
     excellent design and workmanship; simple, and without
     ornamentation.

     "Looking down upon them from a level of the pump house
     gallery, they are impressive and massive in their simplicity.

     "The government is well worth of congratulation in possessing
     the largest pumping machinery of this type and of the
     greatest capacity in the world, and the contractors have
     reason to be proud of their work."--_Proc. Eng. Club._

       *       *       *       *       *




THE PART THAT ELECTRICITY PLAYS IN CRYSTALLIZATION.


Since the discovery of the multiplying galvanometer, we know for an
absolute certainty that in every chemical action there is a production
of electricity in a more or less notable quantity, according to the
nature of the bodies in presence. Though, in the play of _affinity_,
there is a manifestation of electricity, is it the same with
_cohesion_, which also is a chemical force?

We know, on another hand, that, on causing electricity to intervene,
we bring about the crystallization of a large number of substances.
But is the converse true? Is spontaneous crystallization accompanied
with an appreciable manifestation of electricity? If we consult the
annals of science and works treating on electricity in regard to this
subject, we find very few examples and experiments proper to elucidate
the question.

Mr. Mascart is content to say: "Some experiments seem to indicate that
the solidification of a body produces electricity." Mr. Becquerel does
more than doubt--he denies: "As regards the disengagement of
electricity in the changing of the state of bodies, we find none."
This assertion is too sweeping, for further along we shall cite facts
that prove, on the contrary, that in the phenomena of crystallization
(to speak of this change of state only) there is an unequivocal
production of electricity. Let us remark, in the first place, that
when a number of phenomena of physical and chemical order
incontestably testify to the very intimate correlation that exists
between the molecular motions of bodies and their electrical state, it
would not be very logical to grant that electricity is absent in
crystallization.

Thus, to select an example from among physical effects, the vibratory
phenomena that occur in telephone transmissions, under the influence
of a very feeble electric current, show us that the molecular
constitution of a solid body is extremely variable, although within
slight limits. The feeblest modification in the electric current may
be shown by molecular motions capable of propagating themselves to
considerable distances in the conducting wire. Conversely, it is
logical to suppose that a modification in the molecular state of a
body must bring electricity into play. If, in the phenomena of
solidification, and particularly of crystallization, we collect but
small quantities of electricity, that may be due to the fact that,
under the experimental conditions involved, the electricity is more or
less completely absorbed by the work of crystal building.

On another hand, the behavior of electricity shows in advance the
multiple role that this agent may play in the various physical,
chemical, and mechanical phenomena.

There is no doubt that electricity exists immovable or in circulation
everywhere, latent or imperceptible, around us, and within ourselves,
and that it enters as a cause into the majority of the chemical,
physical, and mechanical phenomena that are constantly taking place
before our eyes. A body cannot change state, nature, temperature,
form, or place, even, without electricity being brought into play, and
without its accompanying such modifications, if it presides therein.
Like heat, it is _the_ natural agent _par excellence_; it is the
invisible and ever present force which, in the ultimate particles of
matter, causes those motions, vibrations, and rotations that have the
effect of changing the properties of bodies. Upon entering their
intimate structure, it orients or groups their atoms, and separates
their molecules or brings them together. From this, would it not be
surprising if it did not intervene in the wonderful phenomenon of
crystallization? Crystallization, in fact, depends upon _cohesion_,
and, in the thermic theory, this force is not distinct from affinity,
just as solution and dissociation are not distinct from combination.

On this occasion, it is necessary to say that, between affinity, heat,
and electricity there is such a correlation, such a dependency, that
physicists have endeavored to reduce to one single principle all the
causes that are now distinct. The mechanical theory of heat has made a
great stride in this direction.

The equivalence of the thermic, mechanical and chemical forces has
been demonstrated; the only question hereafter will be to select from
among such forces the one that must be adopted as the sole principle,
in order to account for all the phenomena that depend upon these
causes of various orders. But in the present state of science, it is
not yet possible to explain completely by heat or electricity, taken
isolatedly, all the effects dependent upon the causes just mentioned.
We must confine ourselves for the present to a study of the relations
that exist between the principal natural forces--affinity, molecular
forces, heat, electricity, and light. But from the mutual dependence
of such forces, it is admitted that, in every natural phenomenon,
there is a more or less apparent simultaneous concurrence of these
causes.

In order to explain electric or magnetic phenomena, and also those of
crystallization, it is admitted that the atoms of which bodies are
composed are surrounded, each of them, with a sort of atmosphere
formed of electric currents, owing to which these atoms are attracted
or repelled on certain sides, and produce those varied effects that we
observe under different circumstances. According to this theory, then,
atoms would be small electro-magnets behaving like genuine magnets.
Entirely free in gases, but less so in liquids and still less so in
solids, they are nevertheless capable of arranging themselves and of
becoming polarized in a regular order, special to each kind of atom,
in order to produce crystals of geometrical form characteristic of
each species. Thus, as Mr. Saigey remarks in "Physique Moderne" (p.
181): "So long as the atmospheres of the molecules do not touch each
other, no trace of cohesion manifests itself; but as soon as they come
together force is born. We understand why the temperatures of fusion
and solidification are fixed for the same body. Such effects occur at
the precise moment at which these atmospheres, which are variable with
the temperature, have reached the desired diameter."

[Illustration: Figs. 1., 2., and 3.]

Although the phenomenon of crystallization does not essentially depend
upon temperature, but rather upon the relative quantity of liquid that
holds the substance in solution, it will be conceived that a moment
will arrive when, the liquid having evaporated, the atmospheres will
be close enough to each other to attract each other and become
polarized and symmetrically juxtaposed, and, in a word, to
crystallize.

Before giving examples of the production of electricity in the
phenomenon of crystallization, it will be well to examine, beforehand,
the different circumstances under which electricity acts as the
determining cause of crystallization or intervenes among the causes
that bring about the phenomenon. In the first place, two words
concerning crystallization itself: We know that crystallization is the
passage, or rather the result of the passage, of a body from a liquid
or gaseous state to a solid one. It occurs when the substance has lost
its cohesion through any cause whatever, and when, such cause ceasing
to act, the body slowly returns to a solid state.

Under such circumstances, it may take on regular, geometrical forms
called crystalline. Such conditions are brought about by different
processes--fusion, volatilization, solution, the dry way, wet way, and
electric way. Further along, we shall give some examples of the last
named means.

Let us add that crystallization may be regarded as a general property
of bodies, for the majority of substances are capable of
crystallizing. Although certain bodies seem to be amorphous at first
sight, it is only necessary to examine their fracture with a lens or
microscope to see that they are formed of a large number of small
juxtaposed crystals. Many amorphous precipitates become crystalline in
the long run.

In the examination of the various crystallizations that occupy us, we
shall distinguish the following: (1) Those that are produced through
the direct intervention of the electric current; (2) those in which
electricity is manifestly produced by small voltaic couples resulting
from the presence of two different metals in the solution experimented
with; (3) those in which there are no voltaic couples, but in which it
is proved that electricity is one of the causes that concur in the
production of the phenomenon; (4) finally, those in which it is
rational, through analogy with the preceding, to infer that
electricity is not absent from the phenomenon.

I. We know that, by means of voltaic electricity or induction, we can
crystallize a large number of substances.

Despretz tried this means for months at a time upon carbon, either by
using the electricity from a Ruhmkorff coil or the current from a weak
Daniell's battery. In both cases, he obtained on the platinum wires a
black powder, in which were found very small octohedral crystals,
having the property of polishing rubies rapidly and perfectly--a
property characteristic of diamonds.

The use of voltaic apparatus of high tension has allowed Mr. Cross to
form a large number of mineral substances artificially, and among
these we may mention carbonate of lime, arragonite, quartz, arseniate
of copper, crystalline sulphur, etc.

As regards products formed with the concurrence of electricity
(oxides, sulphides, chlorides, iodides, etc.), see "Des Forces
Physico-Chimiques," by Becquerel (p. 231).

There is no doubt as to the part played by electricity in the chemical
effects of electro-metallurgy, but it will not prove useless for our
subject to remark that when, in this operation, the current has become
too weak, the deposit of metal, instead of forming in a thin,
adherent, and uniform layer, sometimes occurs under the form of
protuberances and crystalline, brittle nodules. When, on the contrary,
the current is very strong, the deposit is pulverulent, that is, in a
confused crystallization or in an amorphous state.

Further along, we shall find an application of this remark. We obtain,
moreover, all the intermediate effects of cohesion, form, and color of
galvanic deposits.

When, into a solution of acetate of lead, we pass a current through
two platinum electrodes, we observe the formation, at the negative
pole, of numerous arborizations of metallic lead that grow under the
observer's eye (Fig. 1). The phenomenon is of a most interesting
character when, by means of solar or electric light, we project these
brilliant vegetations on a screen. One might believe that he was
witness of the rapid growth of a plant (Fig. 2). The same phenomenon
occurs none the less brilliantly with a solution of nitrate of silver.
A large number of saline solutions are adapted to these
decompositions, in which the metal is laid bare under a crystalline
form. Further along we shall see another means of producing analogous
ramifications, without the direct use of the electric current.--_C.
Decharme, in La Lumiere Electrique._

       *       *       *       *       *




ELECTRIC TIME.

By M. LIPPMANN.


The unit of time universally adopted, the second, undergoes only very
slow secular variations, and can be determined with a precision and an
ease which compel its employment. Still it is true that the second is
an arbitrary and a variable unit--arbitrary, in as far as it has no
relation with the properties of matter, with physical constants;
variable, since the duration of the diurnal movement undergoes causes
of secular perturbation, some of which, such as the friction of the
tides, are not as yet calculable.

We may ask if it is possible to define an absolutely invariable unit
of time; it would be desirable to determine with sufficient precision,
if only once in a century, the relation of the second to such a unit,
so that we might verify the variations of the second indirectly and
independently of any astronomical hypothesis.

Now, the study of certain electrical phenomena furnishes a unit of
time which is absolutely invariable, as this magnitude is a specific
constant. Let us consider a conductive substance which may always be
found identical with itself, and to fix our ideas let us choose
mercury, taken at the temperature of 0° C., which completely fulfills
this condition. We may determine by several methods the specific
electric resistance, [rho], of mercury in absolute electrostatic
units; [rho] is a specific property of mercury, and is consequently a
magnitude absolutely invariable. Moreover, [rho] is _an interval of
time_. We might, therefore, take [rho] as a unit of time, unless we
prefer to consider this value as an imperishable standard of time.

In fact, [rho] is not simply a quantity the measure of which is found
to be in relation with the measure of time. It is a concrete interval
of time, disregarding every convention established with reference to
measures and every selection of unit. It may at first sight, appear
singular that an interval of time is found in a manner hidden under
the designation _electric resistance_. But we need merely call to mind
that in the electrostatic system the intensities of the current are
speeds of efflux and that the resistances are times, i.e., the times
necessary for the efflux of the electricity under given conditions. We
must, in particular, remember what is meant by the specific
resistance, [rho] of mercury in the electrostatic system. If we
consider a circuit having a resistance equal to that of a cube of
mercury, the side of which = the unit of length, the circuit being
submitted to an electromotive force equal to unity, this circuit will
take a given time to be traversed by the unit quantity of electricity,
and this time is precisely [rho]. It must be remarked that the
selection of the unit of length, like that of the unit of mass, is
indifferent, for the different units brought here into play depend on
it in such a manner that [rho] is not affected.

It is now required to bring this definition experimentally into
action, i.e., to realize an interval of time which may be a known
multiple of [rho]. This problem may be solved in various ways,[1] and
especially by means of the following apparatus.

   [Footnote 1: In this system the measurement of time is not
    effected, as ordinarily, by observing the movements of a
    material system, but by experiments of equilibrium. All the
    parts of the apparatus remain immovable, the electricity alone
    being in motion. Such appliances are in a manner clepsydræ. This
    analogy with the clepsydræ will be perceived if we consider the
    form of the following experiment: Two immovable metallic plates
    constitute the armatures of a charged condenser, and attract
    each other with a force, F. If the plates are insulated, these
    charges remain constant, as well as the force, F. If, on the
    contrary, we connect the armatures of resistance, R, their
    charges diminish and the force, F, becomes a function of the
    time, _t_; the time, _t_, inversely becomes a function of P. We
    find _t_ by the following formula:

        t = [rho] × (lS / S[pi]es) × log hyp(F0/F)

    F0 and F being the values of the force at the beginning and
    at the end of the time, _t_. The above formula is independent of
    the choice of units. If we wish _t_ to be expressed in seconds,
    we must give [rho] the corresponding value ([rho] = 1.058 X
    10^-16). If we take [rho] as a unit we make [rho] = 1, and we
    find the absolute value of the time by the expression:

        (lS) / (8[pi]es) log hyp(F0/F)

    We remark that this expression of time contains only abstract
    numbers, being independent of the choice of the units of length
    and force. S and _e_ denote surface and the thickness of the
    condenser; _s_ and _l_ the section and the length of a column of
    mercury of the resistance, R. This form of apparatus enables us
    practically to measure the notable values of _t_ only if the
    value of the resistance, R, is enormous, the arrangement
    described in the text has not the same inconvenience.]

A battery of an arbitrary electromotive force, E, actuates at the same
time the two antagonistic circuits of a differential galvanometer. In
the first circuit, which has a resistance, R, the battery sends a
continuous current of the intensity, I; in the second circuit the
battery sends a discontinuous series of discharges, obtained by
charging periodically by means of the battery a condenser of the
capacity, C, which is then discharged through this second circuit. The
needle of the galvanometer remains in equilibrium if the two currents
yield equal quantities of electricity during one and the same time,
[tau].

Let us suppose this condition of equilibrium realized and the needle
remaining motionless at zero; it is easy to write the conditions of
equilibrium. During the time, [tau], the continuous current yields a
                           E
quantity of electricity = -- [tau]; on the other hand, each charge of
                           R
the condenser = CE, and during the time, [tau], the number of
             [tau]
discharges = -----, t being the fixed time between two discharges;
               t
[tau] and t are here supposed to be expressed by the aid of an
arbitrary unit of time; the second circuit yields, therefore, a
                                      [tau]
quantity of electricity equal to CE × -----. The condition of
                                        t
                      E              [tau]
equilibrium is then  ---[tau] = CE × ----- ; or, more simply, t = CR.
                      R                t
C and R are known in absolute values, i.e., we know that C is equal to
_p_ times the capacity of a sphere of the radius, _l_; we have,
therefore, C = _pl_; in the same manner we know that R is equal to _q_
times the resistance of a cube of mercury having l for its side. We
                             l      [rho]
have, therefore, R = q[rho] --- = q ----- ; and consequently t = pq[rho].
                             l²       l

Such is the value of _t_ obtained on leaving all the units
undetermined. If we express [rho] as a function of the second, we have
_t_ in seconds. If we take [rho] = 1, we have the absolute value
[Theta] of the same interval of time as a function of this unit; we
have simply [Theta] = _pq_.

If we suppose that the commutator which produces the successive
charges and discharges of the condenser consists of a vibrating tuning
fork, we see that the duration of a vibration is equal to the product
of the two abstract numbers, _pq_.

It remains for us to ascertain to what degree of approximation we can
determine _p_ and _q_. To find _q_ we must first construct a column of
mercury of known dimensions; this problem was solved by the
International Bureau of Weights and Measures for the construction of
the legal ohm. The legal ohm is supposed to have a resistance equal to
106.00 times that of a cube of mercury of 0.01 meter, side
measurement. The approximation obtained is comprised between 1/50000
and 1/200000. To obtain _p_, we must be able to construct a plane
condenser of known capacity. The difficulty here consists in knowing
with a sufficient approximation the thickness of the stratum of air.
We may employ as armatures two surfaces of glass, ground optically,
silvered to render them conductive, but so slightly as to obtain by
transparence Fizeau's interference rings. Fizeau's method will then
permit us to arrive at a close approximation. In fine, then, we may,
_a priori_, hope to reach an approximation of one hundred-thousandth
of the value of _pq_.

Independently of the use which may be made of it for measuring time in
absolute value, the apparatus described possesses peculiar properties.
It constitutes a kind of clock which indicates, registers, and, if
needful, corrects automatically its own variations of speed. The
apparatus being regulated so that the magnetic needle may be at zero,
if the speed of the commutator is slightly increased, the equilibrium
is disturbed and the magnetic needle deviates in the corresponding
direction; if on the contrary the speed diminishes, the action of the
antagonistic circuit predominates, and the needle deviates in the
contrary direction. These deviations, when small, are proportional to
the variations of speed. They may be, in the first place, observed.
They may, further, be registered, either photographically or by
employing a Redier apparatus, like that which M. Mascart has adapted
to his quadrant electrometer; finally, we may arrange the Redier to
react upon the speed so as to reduce its variations to zero. If these
variations are not completely annulled, they will still be registered
and can be taken into account.

As an indicator of variations this apparatus can be of remarkable
sensitiveness, which may be increased indefinitely by enlarging its
dimensions.

With a battery of 10 volts, a condenser of a microfarad, 10 discharges
per second, and a Thomson's differential galvanometer sensitive to
10^{-10} amperes, we obtain already a sensitiveness of 1/1000000,
i.e., a variation of 1/1000000 in the speed is shown after some
seconds of a deviation of one millimeter. Even the stroboscopic method
does not admit of such sensitiveness.

We may therefore find, with a very close approximation, a speed always
the same on condition that the solid parts of the apparatus (the
condenser and the resistance) are protected from causes of variation
and used always at the same temperature. Doubtless, a well-constructed
astronomical clock maintains a very uniform movement; but the electric
clock is placed in better conditions for invariability, for all the
parts are massive and immovable; they are merely required to remain
unchanged, and there is no question of the wear and tear of
wheel-work, the oxidation of oils, or the variations of weight. In
other words, the system formed by a condenser and a resistance
constitutes a standard of time easy of preservation.

       *       *       *       *       *




NEW METHOD OF MAINTAINING THE VIBRATION OF A PENDULUM.


A recent number of the _Comptes Rendus_ contains a note by M.J.
Carpentier describing a method of maintaining the vibrations of a
pendulum by means of electricity, which differs from previous devices
of the same character in that the impulse given to the pendulum at
each vibration is independent of the strength of the current employed,
and that the pendulum itself is entirely free, save at the point of
suspension. The vibrations are maintained, not by direct impulsion,
but by a slight horizontal displacement of the point of suspension in
alternate directions.

This, as M. Carpentier observes, is the method which we naturally
adopt in order to maintain the amplitude of swing of a heavy body
suspended from a cord held in the hand. The required movement of the
point of suspension is effected by means of a polarized relay, through
the coils of which the current is periodically reversed by the action
of the pendulum, in a manner which will presently be explained. The
armature of the relay oscillates between two stops whose distance
apart is capable of fine adjustment.

It is clear, therefore, that the impulse is independent of the
strength of the current in the relay, provided that the armature is
brought up to the stop on either side. The reversal of the current is
effected by means of a small magnet carried by the bob of the
pendulum, and which as it passes underneath the point of suspension is
brought close to a soft iron armature, which has the form of an arc of
a circle described about the point of suspension. This armature is
pivoted at its center, and thus executes vibrations synchronously with
those of the pendulum. These vibrations are adjusted to a very narrow
range, but are sufficient to close the contacts of a commutator which
reverses the current at each semi-vibration of the pendulum.

The beauty and ingenuity of this device will readily be appreciated.

       *       *       *       *       *




DR. MORELL MACKENZIE.


The name of the great English laryngologist, which has long been
honored by scientists of England and the Continent, has lately become
familar to everyone, even in unprofessional circles, in Germany
because of his operations on the Crown Prince's throat. If his wide
experience and great skill enable him to permanently remove the growth
from the throat of his royal patient, if his diagnosis and prognosis
are confirmed, so that no fear need be entertained for the life and
health of the Crown Prince, the English specialist will certainly
deserve the most sincere thanks of the German nation. Every phase of
this treatment, every new development, is watched with suspense and
hope.

Many have been unable to suppress the expression of regret that this
important case was not under the care of a German, and part of the
press look upon it as unjust treatment of the German specialists. But
science is international, it knows no political boundaries, and the
choice of Dr. Mackenzie by the family of the Crown Prince, whose
sympathy with England is natural, cannot be considered a slight to
German physicians when it is taken into consideration that the German
authorities pronounced the growth suspicious and advised a difficult
and doubtful operation, and that Prof. v. Bergman recommended that a
foreign authority be consulted. As Dr. Mackenzie removed the
obstruction, which had already become threatening and, in fact,
dangerous, causing a loss of voice, and promised to remove any new
growth from the inside without danger to the patient, the Crown Prince
naturally trusted him. Since Virchow has made a microscopic examination
of the part which was cut away, and has declared the new growth to be
benign, all Germans should watch the results of Dr. Mackenzie's
operations with sympathy, trusting that all further growth will be
prevented, and that the Crown Prince will be restored to the German
people in his former state of health.

[Illustration: DR. MORELL MACKENZIE.]

Dr. Morell Mackenzie has lately reached his fiftieth year, and has
attained the height of his fame as an author and practitioner. He was
born at Leytonston in 1837, and studied first in London. At the age
of twenty-two he passed his examination, then practiced as physician
in the London Hospital, and obtained his degree in 1862. A year later
he received the Jackson prize from the Royal Society of Surgeons for
his treatment of a laryngeal case.

He completed his studies in Paris, Vienna (with Siegmund), and
Budapest. In the latter place he worked with Czermak, making a special
study of the laryngoscope. Later he published an excellent work on
"Diseases of the Throat and Nose," which was the fruit of twelve
years' work. The evening before the day on which this work was to have
been issued, the whole edition was destroyed by a fire which occurred
in the printing establishment, and had to be reprinted from the proof
sheets, which were saved. In 1870 his work "On Growths in the Throat"
appeared, and he has also published many articles in the _British
Medical Journal_, the _Lancet_, _Medical Times and Gazette_, etc.,
which have been translated into different languages, making his name
renowned all over Europe.

Since he founded the first English hospital for diseases of the throat
and chest, in London in 1863, and held the position of lecturer on
diseases of the throat in the London Medical College, his career has
been watched with interest by the public, and his practice in England
is remarkable. Therefore it is no wonder that his lately published
work "On the Hygiene of the Vocal Organs" has reached its fourth
edition already. This work is read not only by physicians, but also by
singers and lecturers.

As a learned man in his profession, as an experienced diagnostician,
and as a skillful and fortunate practitioner, he is surpassed by none;
and his ability will be well known far beyond the borders of Great
Britain if fortune favors him and he restores the future Emperor of
Germany to his former strength and vigor, without which we cannot
imagine this knightly form. The certainty with which Dr. Mackenzie
speaks of permanent cures which he has effected in similar cases,
together with the clear and satisfactory report of the great
pathologist Virchow, lead us to look to the future with
confidence.--_Illustrirte Zeitung._

       *       *       *       *       *




HYPNOTISM IN FRANCE.[1]

  [Footnote 1: Translated for _Science_ from _Der Spinx_.]


The voluntary production of those abnormal conditions of the nerves
which to-day are denoted by the term "hypnotic researches" has
manifested itself in all ages and among most of the nations that are
known to us. Within modern times these phenomena were first reduced to
a system by Mesmer, and, on this account, for the future deserve the
attention of the scientific world. The historical description of this
department, if one intends to give a connected account of its
development, and not a series of isolated facts, must begin with a
notice of Mesmer's personality, and we must not confound the more
recent development of our subject with its past history.

The period of mesmerism is sufficiently understood from the numerous
writings on the subject, but it would be a mistake to suppose that in
Braid's "Exposition of Hypnotism" the end of this subject had been
reached. In a later work I hope to show that the fundamental ideas of
biomagnetism have not only had in all periods of this century capable
and enthusiastic advocates, but that even in our day they have been
subjected to tests by French and English investigators from which they
have issued triumphant.

The second division of this historical development is carried on by
Braid, whose most important service was emphasizing the subjectivity
of the phenomena. Without any connection with him, and yet by
following out almost exactly the same experiments, Professor
Heidenhain reached his physiological explanations. A third division is
based upon the discovery of the hypnotic condition in animals, and
connects itself to the _experimentum mirabile_. In 1872 the first
writings on this subject appear from the pen of the physiologist
Czermak; and since then the investigations have been continued,
particularly by Professor Preyer.

While England and Germany were led quite independently to the study of
the same phenomena, France experienced a strange development, which
shows, as nothing else could, how truth everywhere comes to the
surface, and from small beginnings swells to a flood which carries
irresistibly all opposition with it. This fourth division of the
history of hypnotism is the more important, because it forms the
foundation of a transcendental psychology, and will exert a great
influence upon our future culture; and it is this division to which we
wish to turn our attention. We have intentionally limited ourselves to
a chronological arrangement, since a systematic account would
necessarily fall into the study of single phenomena, and would far
exceed the space offered to us.

James Braid's writings, although they were discussed in detail in
Littré and Robin's "Lexicon," were not at all the cause of Dr.
Philips' first books, who therefore came more independently to the
study of the same phenomena. Braid's theories became known to him
later by the observations made upon them in Béraud's "Elements of
Physiology" and in Littré's notes in the translation of Müller's
"Handbook of Physiology;" and he then wrote a second brochure, in
which he gave in his allegiance to braidism. His principal effort was
directed to withdrawing the veil of mystery from the occurrences, and
by a natural explanation relegating them to the realm of the known.
The trance caused by regarding fixedly a gleaming point produces in
the brain, in his opinion, an accumulation of a peculiar nervous
power, which he calls "electrodynamism." If this is directed in a
skillful manner by the operator upon certain points, it manifests
itself in certain situations and actions that we call hypnotic. Beyond
this somewhat questionable theory, both books contained a detailed
description of some of the most important phenomena; but with the
practical meaning of the phenomena, and especially with their
therapeutic value, the author concerned himself but slightly. Just on
account of this pathological side, however, a certain attention has
been paid to hypnotism up to the present time.

In the year 1847 two surgeons in Poictiers, Drs. Ribaut and Kiaros,
employed hypnotism with great success in order to make an operation
painless. "This long and horrible work," says a journal of the day,
"was much more like a demonstration in a dissecting room than an
operation performed upon a living being." Although this operation
produced such an excitement, yet it was twelve years later before
decisive and positive official intelligence was given of these facts
by Broca, Follin, Velpeau, and Guérinau. But these accounts, as well
as the excellent little book by Dr. Azam, shared the fate of their
predecessors. They were looked upon by students with distrust, and by
the disciples of Mesmer with scornful contempt.

The work of Demarquay and Giraud Teulon showed considerable advance in
this direction. The authors, indeed, fell back upon the theory of
James Braid, which they called stillborn, and of which they said,
"_Elle est restée accrochée en route_;" but they did not satisfy
themselves with a simple statement of facts, as did Gigot Suard in his
work that appeared about the same time. Through systematic experiments
they tried to find out where the line of hypnotic phenomena intersected
the line of the realm of the known. They justly recognized that
hypnotism and hysteria have many points of likeness, and in this way
were the precursors of the present Parisian school. They say that from
magnetic sleep to the hypnotic condition an iron chain can be easily
formed from the very same organic elements that we find in historical
conditions.

At the same time, as if to bring an experimental proof of this
assertion, Lasigue published a report on catalepsy in persons of
hysterical tendencies, which be afterward incorporated into his larger
work. Among his patients, those who were of a quiet and lethargic
temperament, by simply pressing down the eyelids, were made to enter
into a peculiar state of languor, in which cataleptic contractions
were easily produced, and which forcibly recalled hypnotic phenomena.
"One can scarcely imagine," says the author, "a more remarkable
spectacle than that of a sick person sunk in deep sleep, and
insensible to all efforts to arouse him, who retains every position in
which he is placed, and in it preserves the immobility and rigidity of
a statue." But this impulse also was in vain, and in only a few cases
were the practical tests followed up with theoretical explanations.

Unbounded enthusiasm and unjust blame alike subsided into a silence
that was not broken for ten years. Then Charles Richet, a renowned
scientist, came forward in 1875, impelled by the duty he felt he owed
as a priest of truth, and made some announcements concerning the
phenomena of somnambulism; and in countless books, all of which are
worthy of attention, he has since then considered the problem from its
various sides.

He separates somnambulism into three periods. The word here is used
for this whole class of subjects as Richet himself uses it, viz.,
_torpeur_, _excitation_, and _stupeur_. In the first, which is
produced by the so-called magnetic passes and the fixing of the eyes,
silence and languor come over the subject. The second period, usually
produced by constant repetition of the experiment, is characterized
chiefly by sensibility to hallucination and suggestion. The third
period has as its principal characteristics supersensibility of the
muscles and lack of sensation. Yet let it be noticed that these
divisions were not expressed in their present clearness until 1880;
while in the years between 1872 and 1880, from an entirely different
quarter, a similar hypothesis was made out for hypnotic phenomena.

Jean Martin Charcot, the renowned neurologist of the Parisian
Salpetriere, without exactly desiring it, was led into the study of
artificial somnambulism by his careful experiments in reference to
hysteria, and especially by the question of _metallotherapie_, and in
the year 1879 had prepared suitable demonstrations, which were given
in public lectures at the Salpetriere. In the following years he
devoted himself to closer investigation of this subject, and was
happily and skillfully assisted by Dr. Paul Richer, with whom were
associated many other physicians, such as Bourneville, Regnard, Fere,
and Binet. The investigations of these men present the peculiarity
that they observe hypnotism from its clinical and nosographical side,
which side had until now been entirely neglected, and that they
observe patients of the strongest hysterical temperaments. "If we can
reasonably assert that the hypnotic phenomena which depend upon the
disturbance of a regular function of the organism demand for their
development a peculiar temperament, then we shall find the most marked
phenomena when we turn to an hysterical person."

The inferences of the Parisian school up to this time are somewhat the
following, but their results, belonging almost entirely to the medical
side of the question, can have no place in this discussion. They
divide the phenomena of hystero-hypnotism, which they also call
_grande hysterie_, into three plainly separable classes, which Charcot
designates catalepsy, lethargy, and somnambulism.

Catalepsy is produced by a sudden sharp noise, or by the sight of a
brightly gleaming object. It also produces itself in a person who is
in a state of lethargy, and whose eyes are opened. The most striking
characteristic of the cataleptic condition is immobility. The subject
retains every position in which he is placed, even if it is an
unnatural one, and is only aroused by the action of suggestion from
the rigor of a statue to the half life of an automaton. The face is
expressionless and the eyes wide open. If they are closed, the patient
falls into a lethargy.

In this second condition, behind the tightly closed lids, the pupils
of the eyes are convulsively turned upward. The body is almost
entirely without sensation or power of thought. Especially
characteristic of lethargy is the hyper-excitability of the nerves and
muscles (_hyperexcitabilite neuromusculaire_), which manifests itself
at the slightest touch of any object. For instance, if the extensor
muscles of the arm are lightly touched, the arm stiffens immediately,
and is only made flexible again by a hard rubbing of the same muscles.
The nerves also react in a similar manner. The irritation of a nerve
trunk not only contracts all the small nerves into which it branches,
but also all those muscles through which it runs.

Finally, the somnambulistic condition proceeds from catalepsy or from
lethargy by means of a slight pressure upon the _vertex_, and is
particularly sensitive to every psychical influence. In some subjects
the eyes are open, in others closed. Here, also, a slight irritation
produces a certain amount of rigor in the muscle that has been
touched, but it does not weaken the antagonistic muscle, as in
lethargy, nor does it vanish under the influence of the same
excitement that has produced it. In order to put an end to the
somnambulistic condition, one must press softly upon the pupil of the
eye, upon which the subject becomes lethargic, and is easily roused by
breathing upon him. In this early stage, somnambulism appears very
infrequently.

Charcot's school also recognize the existence of compound conditions,
the history of whose symptoms we must not follow here. These slightly
sketched results, as well as a number of other facts, were only
obtained in the course of several years; yet in 1882 the fundamental
investigations of this school were considered virtually concluded.
Then Dumont-Pallier, the head of the Parisian Hospital Pitié, came
forward with a number of observations, drawn also exclusively from the
study of hystero-hypnotism, and yet differing widely from those
reached by the physicians of the Salpetriere. In a long series of
communications, he has given his views, which have in their turn been
violently attacked, especially by Magnin and Bérillon. I give only the
most important points.

According to these men, the hyper-excitability of the nerves and
muscles is present not only in the lethargic condition, but in all
three periods; and in order to prove this, we need only apply the
suitable remedy, which must be changed for each period and every
subject. Slight irritations of the skin prove this most powerfully. A
drop of warm water or a ray of sunshine produces contractions of a
muscle whose skin covering they touch.

Dumont-Pallier and Magnin accede to the theory of intermediate stages,
and have tried to lay down rules for them with as great exactness as
Charcot's school. They also are very decided about the three periods,
whose succession does not appear to them as fixed; but they discovered
a new fundamental law which regulates the production as well as the
cessation of the condition--_La cause qui fait, defait_; that is, the
stimulus which produces one of the three periods needs only to be
repeated in order to do away with that condition. From this the
following diagram of hypnotic conditions is evolved:

[Illustration]

And, furthermore, Dumont-Pallier should be considered as the founder
of a series of experiments, for he was the first one to show in a
decisive manner that the duality of the cerebral system was proved by
these hypnotic phenomena; and his works, as well as those of Messrs.
Bérillon and Descourtis, have brought to light the following facts:
Under hypnotic conditions, the psychical activity of a brain
hemisphere may be suppressed without nullifying the intellectual
activity or consciousness. Both hemispheres may be started at the same
time in different degrees of activity; and also, when the grade is the
same, they may be independently the seat of psychical manifestations
which are in their natures entirely different. In close connection
with this and with the whole doctrine of hemi-hypnotism, which is
founded upon these facts, stand the phenomena of thought transference,
which we must consider later.

As an addition to the investigations of Charcot and Dumont-Pallier,
Brémaud, in 1884, made the discovery that there was a fourth hypnotic
state, "fascination," which preceded the three others, and manifested
itself by a tendency to muscular contractions, as well as through
sensitiveness to hallucination and suggestion, but at the same time
left to the subject a full consciousness of his surroundings and
remembrance of what had taken place. Descourtis, in addition,
perceived a similar condition in the transition from hypnotic sleep to
waking, which he called _delire posthypnotique_, and, instead of using
the word "fascination" to express the opening stage, he substituted
"captation." According to him, the diagram would be the following:

[Illustration]

This whole movement, which I have tried to sketch, and whose chief
peculiarity is that it considers hypnotism a nervous malady, and one
that must be treated clinically and nosographically, was opposed in
1880 in two directions--one source of opposition producing great
results, while the other fell to the ground. The latter joined itself
to the theory of the mesmerists, and tried, by means of exact
experiments, to measure the fluid emanating from the human body--an
undertaking which gave slight promise of any satisfactory result.

Baillif in his thesis (1878) and Chevillard in his (for spiritualists)
very interesting books, tried, by means of various arguments, to
uphold the fluidic explanation. Despine also thought that by its help
he had been able to explain the phenomena; but it was Baréty who, in
the year 1881, first turned general attention in this direction.
According to him, mankind possesses a nerve force which emanates from
him in different kinds of streams. Those coming from the eyes and
fingers produce insensibility to pain, while those generated by the
breath cause hypnotic conditions. This nerve force goes out into the
ether, and there obeys the laws that govern light, being broken into
spectra, etc.

Claude Perronnet has more lately advanced similar views, and his
greatest work is now in press. Frederick W.H. Myers and Edmund Gurney
sympathize with these views, and try to unite them with the mesmerist
doctrine of personal influence and their theory of telepathy. The
third champion in England of hypnotism, Prof. Hack Tuke, on the
contrary, sympathizes entirely with the Parisian school, only
differing from them in that he has experimented with satisfactory
results upon healthy subjects. In France this view has lately been
accepted by Dr. Bottey, who recognizes the three hypnotic stages in
healthy persons, but has observed other phenomena in them, and
vehemently opposes the conception of hypnotism as a malady. His
excellently written book is particularly commended to those who wish
to experiment in the same manner as the French investigator, without
using hysterical subjects.

The second counter current that opposed itself to the French
neuropathologists, and produced the most lasting impression, is
expressed by the magic word "suggestion." A generation ago, Dr.
Liebault, the patient investigator and skillful physician, had
endeavored to make a remedial use of suggestion in his clinic at
Nancy. Charles Richet and others have since referred to it, but
Professor Bernheim was the first one to demonstrate its full
significance in the realm of hypnotism. According to him,
suggestion--that is, the influence of any idea, whether received
through the senses or in a hypersensible manner (_suggestion
mentale_)--is the key to all hypnotic phenomena. He has not been able
in a single case to verify the bodily phenomena of _grandehypnotisme_
without finding suggestion the primary cause, and on this account
denies the truth of the asserted physical causes. Bernheim says that
when the intense expectance of the subject has produced a compliant
condition, a peculiar capacity is developed to change the idea that
has been received into an action as well as a great acuteness of
acceptation, which together will produce all those phenomena that we
should call by the name of "pathological sleep," since they are only
separable in a gradual way from the ordinary sleep and dream
conditions. Bernheim is particularly strenuous that psychology should
appear in the foreground of hypnotism, and on this point has been
strongly upheld by men like Professors Beaunis and Richet.

The possibility of suggestion in waking conditions, and also a long
time after the sleep has passed off (_suggestions posthypnotiques ou
suggestions a (longue) echeance_), as well as the remarkable capacity
of subjects to change their personality (_changement de la
personnalite objectivation des types_), have been made the subject of
careful investigation. The voluntary production of bleeding and
stigmata through spiritual influence has been asserted, particularly
by Messrs. Tocachon, Bourru, and Burot. The judicial significance of
suggestion has been discussed by Professor Liegeois and Dr. Ladame.
Professor Pitres in Bordeaux is one of the suggestionists, though
differing in many points from the Nancy school.

This whole tendency brings into prominence the psychical influence,
while it denies the production of these results from purely physical
phenomena, endeavoring to explain them in a different manner. These
explanations carry us into two realms, the first of which has been
lately opened, and at present seems to abound more in enigmas than in
solutions.

_Metallotherapie_, which was called into existence by Dr. Burg, and
further extended by Dr. Gellé, contains a special point of
interest--the so-called transference in the case of hysterically or
hypnotically affected persons. Transference is caused by
electro-magnetism, which has this peculiarity--that in the case of
specially sensitive persons it can transfer the bodily affection from
left to right, and _vice versa_. The transference of paralysis, the
cures attempted on this plan, and the so-called "psychical
transference," which contains special interest for graphologists, are
at the present time still open questions, as well as the closely
connected theory of human polarity; and the odic experiments of Dr.
Chazarain are yet waiting for their confirmation. At present the
problem of the connection between magnetism and hypnotism is under
investigation, and in such a manner that we may hope for a speedy
solution.

Still stranger than these reports are the accounts of the distant
operation of certain bodies; at least, they seem strange to those
unacquainted with psychometry and the literature of the past century
relating to this subject. Two physicians in Rochefort, Professors
Bourru and Burot, in treating a hystero-epileptic person, found that
gold, even when at a distance of fifteen centimeters, produced in him
a feeling of unbearable heat. They continued these experiments with
great care, and, after a number of trials, came to this
conclusion--that in some persons certain substances, even when
carefully separated from them by long distance, exercise exactly the
same physiological influence as if introduced into their organism. In
order to explain these phenomena, they refer to the radiating force of
Baréty, an explanation neither satisfactory to themselves nor to
others. Lately the distinguished Parisian physician, Dr. Luys, has
confirmed by his experiments the existence of these phenomena, but he
thinks the explanation referable to hyper-sensitiveness of the
"_regions emotives et intellectuelles de l'encephale_" yet even he has
not reached the kernel of the difficulty.

In close connection with action at a distance is the question of
distant production of hypnotic sleep. For an answer to this problem,
they are experimenting in both France and England; and Frederick W.H.
Myers has thrown an entirely new light upon the subject by the
investigations he is making upon a purely experimental basis. In Italy
they have limited themselves to the study of isolated cases of
hystero-hypnotism, except as the phenomena of magnetic fascination
investigated by Donato have given rise to further research; but all
the books I have seen upon this subject, as well as many by French
authors, suffer from ignorance of the latest English discoveries.

With this I think that I have given a slight outline of the history of
hypnotic investigation to the end of the year 1886. I shall attempt a
criticism of this whole movement at some other time, as space is not
afforded to me here; but I should like to make this statement now,
that two of the characteristic indications of this period are of the
gravest import--first the method ("Our work," says Richet, "is that of
strictly scientific _testing_, _observation_, and _arrangement_");
and, secondly, the result. Hypnotism has been received into the realm
of scientific investigation, and with this the foundation of a true
experimental psychology has been laid.

MAX DESSOIR.

       *       *       *       *       *




THE DUODENUM: A SIPHON TRAP.

By MAYO COLLIER, M.S. Lond., F.R.C.S. Eng.; Senior
Assistant Surgeon, North-West London Hospital; Assistant Demonstrator
of Anatomy, London Hospital Medical College.


We may take it for granted that all gases generated in the jejunum,
ileum, and large intestines pass onward toward the anus, and there
sooner or later escape. Fetid gases--except those generated in the
stomach and duodenum--never pass upward, not even during vomiting due
to hernia, obstruction, and other causes. Physiologists, it would
appear, have never busied themselves to find an explanation for this
apparent breach of the laws of gravity. The intestinal canal is a tube
with various dilatations and constrictions, but at no spot except the
pylorus does the constriction completely obliterate the lumen of the
tube, and here only periodically. It is perfectly evident, then, that,
unless some system of trap exists in the canal, gases are free to
travel from below upward in obedience to the laws of gravity, and
would, as a matter of fact, sooner or later do so. From the straight,
course and vertical position of the oesophagus, a very slight
pressure of gas in the stomach easily overcomes the closure of its
cardiac sphincter and allows of escape. When the stomach has digested
its contents and the pylorus is relaxed, gases generated in the
duodenum can and do ascend into the stomach and so escape. Normally,
no fetid gases are generated in the stomach or duodenum. If we follow
the course of the intestines down, we find that the duodenum presents
a remarkable curve.

Now, there are some points of great interest in connection with this
remarkable, almost circular, curve of the duodenum. In the first
place, this curve is a constant feature in all mammalians. Mr. Treves
says it is one of the most constant features in the anatomy of the
intestines in man, and, speaking of mammalians in general, that the
curve of the duodenum varies in shape, but is never absent, becoming
more complex in some of the higher primates, but seldom less distinct
than in man. In birds the duodenum always forms a long loop embracing
the pancreas.

A second point of great interest is the absolute constancy and
fixation of its terminal portion at the point of junction with the
jejunum, more correctly termed second ascending or fourth portion. Mr.
Treves says that this fourth portion is never less than an inch, and
is practically constant. It extends along the side of the left crus of
the diaphragm opposite the second lumbar vertebra, and is there firmly
fixed to the front of the aorta and crus of the diaphragm by a strong
fibro-muscular band, slinging it up and absolutely retaining it in
position. This band has been termed the "musculus suspensorius
duodeni," but is chiefly composed of white fibrous tissue, and is more
of the native of a ligament than a muscle. This ligament is always
present, and its position is never altered. The curve of the duodenum
may descend as far as the iliac fossa, but the terminal portion is
always maintained by this band in its normal position.

Another point of great constancy is the position of the pancreas and
its relation to the curve of the duodenum. The duodenum always curves
round the head of the pancreas and is, as it were, moulded on it and
retained in position by it. In birds the duodenum always forms a long
loop embracing the pancreas. Further, the ducts of the liver and
pancreas always open into the center Of the duodenum, either
separately or by a common opening.

[Illustration]

Now, the absolute constancy of the curve of the duodenum, the complete
fixation of its fourth portion, the position of the pancreas, and the
place of entry of the ducts of the pancreas and liver, are all
component parts of a siphon trap, whereby gases generated below the
duodenum are prevented from passing upward. A reference to the
accompanying diagrams will make this quite clear. A is a diagram of a
siphon trap copied from Parkes' hygiene. B is a very diagrammatic
outline of the stomach and duodenum, _a_ is intended to mark the
position of the fibrous band, or musculus suspensorius duodeni; and
_b_ the position of entry of the ducts of the liver and pancreas. The
duodenum, then, is a siphon trap, and a most efficient one. Now, the
efficiency of a siphon trap depends not only on its shape, but what is
absolutely essential is that the curve must be kept constantly full of
fluid, without which it ceases to be a trap, and would allow gases to
ascend freely. The position of the place of entry of the ducts of the
pancreas and liver assures that this _sine qua non_ shall be present.
The discharge of the secretions of the pancreas and liver, although
more active during and after feeding, is practically constant, and so
insures in an admirable manner that the curve on which the efficiency
of the trap depends shall be constantly kept full not only with fluid,
but, as I would suggest, antiseptic fluid. There is no other trap in
the intestinal canal, but the peculiar position of the colon would no
doubt have more or less effect in preventing gases ascending through
the ileo-cæcal valve.--_Lancet._

       *       *       *       *       *




WISCONSIN CRANBERRY CULTURE.


Among the many thousands of well informed persons with whom the
cranberry is a staple article of food throughout the autumn and
winter, and who especially derive from its pungent flavor sharp relish
for their Thanksgiving and Christmas turkey, not one in ten has any
definite idea as to where the delicious fruit comes from, or of the
method of growing and harvesting it. Most people are, however, aware
that it is raised on little "truck patches" somewhere down in New
Jersey or about Cape Cod, and some have heard that it is gleaned from
the swamps in the Far West by Indians and shipped to market by white
traders. But to the great majority its real history is unknown.

Yet the cranberry culture is an industry in which millions of dollars
are invested in this country, and it gives employment, for at least a
portion of each year, to many thousands of people. In the East, where
the value of an acre of even swamp land may run up into the thousands
of dollars, a cranberry marsh of five or ten acres is considered a
large one, and, cultivated in the careful, frugal style in vogue
there, may yield its owner a handsome yearly income. But in the great,
boundless West, where land, and more especially swamp land, may be had
for from $1 to $5 an acre, we do these things differently, if not
better.

The State of Wisconsin produces nearly one-half of the cranberries
annually grown in the United States. There are marshes there covering
thousands of acres, whereon this fruit grows wild, having done so even
as far back as the oldest tradition of the native red man extends. In
many cases the land on which the berries grow has been bought from the
government by individuals or firms, in vast tracts, and the growth of
the fruit promoted and encouraged by a system of dikes and dams
whereby the effects of droughts, frost, and heavy rainfalls are
counteracted to almost any extent desired. Some of these holdings
aggregate many thousands of acres under a single ownership; and after
a marsh of this vast extent has been thoroughly ditched and good
buildings, water works, etc., are erected on it, its value may reach
many thousands of dollars, while the original cost of the land may
have been merely nominal.

Large portions of Jackson, Wood, Monroe, Marinette, Juneau, and Green
counties are natural cranberry marshes. The Wisconsin Valley division
of the Chicago, Milwaukee & St. Paul Railway runs through a closely
continuous marsh, forty miles long and nearly as wide, as level as a
floor, which is an almost unbroken series of cranberry farms. The
Indians, who inhabited this country before the white man came, used to
congregate here every fall, many of them traveling several hundred
miles, to lay in their winter supply of berries. Many thousands of
barrels are now annually shipped from this region; and thus this vast
area, which to the stranger looking upon it would appear utterly
worthless, is as valuable as the richest farming lands in the State.

In a few instances, however, this fruit is cultivated in Wisconsin in
a style similar to that practiced in the East; that is, by paring the
natural sod from the bog, covering the earth to a depth of two or
three inches with sand, and then transplanting the vines into soil
thus prepared. The weeds are then kept down for a year or two, when
the vines take full possession of the soil, and further attention is
unnecessary. The natural "stand" of the vines in the sod is so
productive, however, and the extent of country over which bountiful
nature has distributed them so vast, that few operators have thought
it necessary to incur the expense of special culture.

One of the best and most perfectly equipped marshes in Wisconsin is
owned by Mr. G.B. Sackett, of Berlin. It is situated four miles north
of that village, and comprises 1,600 acres, nearly all of which is a
veritable bog, and is covered with a natural and luxuriant growth of
cranberry vines. A canal has been cut from the Fox River to the
southern limit of the marsh, a distance of 4,400 ft. It is 45 ft.
wide, and the water stands in it to a depth of nine feet, sufficient
to float fair sized steamboats. At the intersection of the canal with
the marsh steam water works have been erected, with flood gates and
dams by means of which the entire marsh may be flooded to a depth of a
foot or more when desired. There are two engines of 150 horse power
each, and two pumps that are capable of raising 80,000 gallons per
minute.

When, in early autumn, the meteorological conditions indicate the
approach of frost, the pumps may he put to work in the afternoon and
the berries be effectually covered by water and thus protected before
nightfall. At sunrise the gates are opened and the water allowed to
run off again, so that the pickers may proceed with their work. The
marsh is flooded to a depth of about two feet at the beginning of each
winter and allowed to remain so until spring, the heavy body of ice
that forms preventing the upheaval that would result from freezing and
thawing--a natural process which, if permitted, works injury to the
vines.

There is a three-story warehouse on the marsh, with a capacity of
20,000 barrels of berries, and four large two-story houses capable of
furnishing shelter for 1,500 pickers. The superintendent's residence
is a comfortable cottage house, surrounded by giant oaks and elms, and
stands near the warehouse on an "island," or small tract of high, dry
land near the center of the great marsh. The pickers' quarters stand
on another island about 200 yards away.

A plank roadway, built on piles, about two feet above the level of the
ground, leads from the mainland to the warehouse and other buildings,
a distance of more than half a mile. Several wooden railways diverge
from the warehouse to all parts of the marsh, and on them flat cars,
propelled by hand, are sent out at intervals during the picking season
to bring in the berries from the hands of the pickers. Each picker is
provided with a crate, holding just a bushel, which is kept close at
hand. The berries are first picked into tin pans and pails, and from
these emptied into the crates, in which they are carried to the
warehouse, where an empty crate is given the picker in exchange for a
full one. Thus equipped and improved, the Sackett marsh is valued at
$150,000. Thirteen thousand barrels have been harvested from this
great farm in a single season. The selling price in the Chicago market
varies, in different seasons, from $8 to $16 per barrel. There are
several other marshes of various sizes in the vicinity.

The picking season usually begins about Sept. 1, and from that time
until Oct. 1 the marshes swarm with men, women, and children, ranging
in age from six to eight years, made up from almost every nationality
under the sun. Bohemians and Poles furnish the majority of the working
force, while Germans, Irish, Swedes, Norwegians, Danes, negroes,
Indians, and Americans contribute to the motley contingent. They come
from every direction and from various distances, some of them
traveling a hundred miles or more to secure a few days' or weeks'
work. Almost every farmer or woodsman living anywhere in the region of
the marshes turns out with his entire family; and the families of all
the laboring men and mechanics of the surrounding towns and cities
join in the general hegira to the bogs, and help to harvest the fruit.
Those living within a few miles go out in the morning and return home
at night, taking their noon-day meal with them, while those from a
distance take provisions and bedding with them and camp in the
buildings provided for that purpose by the marsh owners, doing their
own cooking on the stoves and with the fuel furnished them.

The wages vary from fifty cents to a dollar a bushel, owing to the
abundance or scarcity of the fruit. A good picker will gather from
three to four bushels a day where the yield is light, and five to six
bushels where it is good. The most money is made by families numbering
from half a dozen to a dozen members. Every chick and child in such
families over six years old is required to turn out and help swell the
revenue of the little household, and the frugal father often pockets
ten to twenty dollars a day as the fruits of the combined labors. The
pickers wade into the grass, weeds, and vines, however wet with dew or
rain, or however deeply flooded underneath, making not the slightest
effort to keep even their feet dry, and after an hour's work in the
morning are almost as wet as if they had swum a river. Many of them
wade in barefooted, others wearing low cowhide shoes, and their feet,
at least, are necessarily wet all day long. In many cases their bodies
are thinly clad, and they must inevitably suffer in frosty mornings
and evenings and on the raw, cold, rainy days that are frequent in the
autumn months in this latitude; yet they go about their work singing,
shouting, and jabbering as merrily as a party of comfortably clad
school children at play. How any of them avoid colds, rheumatism, and
a dozen other diseases is a mystery; and yet it is rarely that one of
them is ill from the effects of this exposure. As many as 3000 or 4000
pickers are sometimes employed on a single marsh when there is a heavy
crop, and an army of such ragamuffins as get together for this
purpose, scattered over a bog in confusion and disorder, presents a
strange and picturesque appearance.

Indians are not usually as good pickers as white people, but in the
sparsely settled districts, where many of the berry farms are
situated, it is impossible to get white help enough to take care of
the crop in the short time available for the work, and owners are
compelled to employ the aborigines. A rake, with the prongs shaped
like the letter V, is used for picking in some cases, but owing to the
large amount of grass and weeds that grow among the vines on these
wild marshes, this instrument is rarely available. After being picked
the berries are stored in warehouses for a period varying from one to
three weeks. They are washed and dried by being passed through a
fanning mill made for the purpose, and are then allowed to cure and
ripen thoroughly before they are shipped to market.

From statistics gathered by the American Cranberry Growers'
Association it is learned that in 1883 Wisconsin produced 135,507
bushels, in 1884 24,738 bushels, in 1885 264,432 bushels, and in 1886
70,686 bushels of this fruit. By these figures it will be seen that
the yield is very irregular. This is owing, principally, to the fact
that many of the marshes are not yet provided with the means of
flooding, and of course suffer from worms, droughts, late spring or
early autumn frosts, and extensive fires started by sparks from the
engines on railroads running through the marshes. These and various
other evils are averted on the more improved farms. So that, while
handsome fortunes have in many cases been made in cranberry growing,
many thousands of dollars have, on the other hand, been sunk in the
same industry. Only the wealthier owners, who have expended vast sums
of money in improving and equipping their property, can calculate with
any degree of certainty on a paying crop of fruit every year.

Chicago is the great distributing point for the berries produced in
Wisconsin, shipments being made thence to nearly every State and
Territory in the Union, to Canada, to Mexico, and to several European
countries. Berries sent to the Southern markets are put up in
watertight packages, and the casks are then filled with water, this
being the only means by which they can be kept in hot weather. Even in
this condition they can only be kept a few days after reaching hot
climates.--_American Magazine._

       *       *       *       *       *




SOUDAN COFFEE.

(_Parkia biglobosa._)


There are valuable plants on every continent. Civilized Europe no
longer counts them. Mysterious Africa is no less largely and
spontaneously favored with them than young America and the ancient
territory of Asia.

The latter has given us the majority of the best fruits of our
gardens. We have already shown how useful the butter tree
(_Butyrospermum Parkii_) is in tropical Africa, and we also know how
the _gourou_ (_Sterculia acuminata_) is cultivated in the same
regions. But that is not all, for the great family of Leguminosæ,
whose numerous representatives encumber this continent, likewise
furnishes the negro natives a food that is nearly as indispensable to
them as the _gourou_ or the products of the baobab--another valuable
tree and certainly the most widely distributed one in torrid Africa.
This leguminous tree, which is as yet but little known in the
civilized world, has been named scientifically _Parkia biglobosa_ by
Bentham. The negroes give it various names, according to the tribe;
among the Ouloffs, it is the _houlle_; among the Mandigues, _naytay_;
in Cazamance (Nalon language), it is _nayray_; in Bornou, _rounuo_; in
Haoussa, _doroa_; in Hant-fleure (Senegal), _nayraytou_. On the old
mysterious continent it plays the same role that the algarobas do in
young America. However, it is quite a common rule to find in the order
Leguminosæ, and especially in the section Mimosæ, plants whose pods
are edible. Examples of this fact are numerous. As regards the
Mediterranean region, it suffices to cite the classic carob tree
(_Ceratonia siliqua_), which also is of African nationality, but which
is wanting in the warm region of this continent.

Throughout the tropical region of Africa, the aborigines love to
consume the saccharine pulp and the seed contained in the pod of the
_houlle_. Prepared in different ways, according to tribe and latitude,
these two products constitute a valuable aliment. The pulp is consumed
either just as it is or as a fermented beverage. As for the seeds,
they serve, raw or roasted, for the production of a tea-like infusion
(whence the name "Soudan coffee"), or, after fermentation in water,
for making a national condiment, which in certain places is called
_kinda_, and which is mixed with boiled rice or prepared meats. This
preparation has in most cases a pasty form or the consistency of
cohesive flour; but in order to render its carriage easier in certain
of the African centers where the trade in it is brisk, it is
compressed into tablets similar to those of our chocolate. As these
two products are very little known in Europe, it has seemed to us that
it would be of interest to give a description and chemical analysis of
them. We shall say but little of the plant, which has sufficiently
occupied botanists.

[Illustration: Figs. 1 TO 6.--PODS OF THE HOULLE AND MICROSCOPIC
DETAILS.]

The houlle (_Parkia biglobosa_) is a large tree from 35 to 50 feet in
height, with a gray bark, many branches, and large, elegant leaves.
The latter are compound, bipinnate (Fig. 7), and have fifty pairs of
leaflets, which are linear and obtuse and of a grayish green. The
inflorescence is very pleasing to the eye. The flowers, say the
authors of the _Floræ Senegambiæ Tentamen_, form balls of a dazzling
red, contracted at the base, and resembling the pompons of our
grenadiers (Fig. 8). The support of this latter consists only of male
flowers. The fruit that succeeds these flowers is supported by a
club-shaped receptacle. It consists of a large pod, which at maturity
is 13 inches in length by 10 in width (Fig. 1). This pod is chocolate
brown, quite smooth or slightly tubercular, and is swollen at the
points where the seeds are situated. The pods are straight or slightly
curved. The aborigines of Rio Nunez use the pods for poisoning the
fishes that abound in the watercourses. We do not know what the nature
of the toxic principle is that is contained in these hard pods, but we
well know the nature of the yellowish pulp and of the seeds that
entirely fill the pods.

[Illustration: Fig. 7.--PARKIA BIGLOBOSA.]

Although the pulp forms a continuous whole, each seed easily separates
from the following and carries with it a part of the pulp that
surrounds it and that constitutes an independent mass (Fig. 2). This
pulpy substance, formed entirely of oval cells filled with aleurone,
consists of two distinct layers. The first, an external one of a
beautiful yellow, is from 10 to 15 times bulkier than the internal
one, which likewise is of a beautiful yellow.

[Illustration: Fig. 8--FLOWERS OF PARKIA.]

It detaches itself easily from the seed, while the internal layer,
which adheres firmly to the exterior of the seed, can be detached only
by maceration in water. This fresh pulp has a sweet and agreeable
although slightly insipid taste. Upon growing old and becoming dry, it
takes on a still more agreeable taste, for it preserves its sweetness
and gets a perfume like that of the violet.

As for the seed, which is of a brown color and provided with a hard,
shining skin, that is 0.4 inch long, 0.3 inch wide, and 0.2 inch
thick. It is oval in form, with quite a prominent beak at the hilum
(Fig. 4). The margin is blunt and the two convex sides are provided in
the center with a gibbosity limited by a line parallel with the
margin, and this has given the plant its specific name of _biglobosa_.
The mean weight of each seed is 4½ grains. The skin, though thick, is
not very strong. It consists, anatomically, of four layers (Fig. 5) of
a thick cuticle, _c_; of a zone of palissade cells, _z p_; of a zone
of cells with thick tangential walls arranged in a single row; and of
a zone tougher than the others, formed of numerous cells with thick
walls, without definite form, and filled with a blackish red coloring
matter, _cs_. This perisperm covers an exalbuminous embryo formed
almost entirely of two thick, greenish yellow cotyledons having a
strong taste of legumine.

When examined under the microscope, these cotyledons, the alimentary
part of the seed, have the appearance represented in Fig. 6, where
_ep_ is the epidermic layer and _cp_ constitutes the uniform
parenchyma of the cotyledonary leaf. This parenchymatous mass consists
of oval cells filled with fatty matter and granules of aleurone.

According to some chemical researches made by Professor
Schlagdenhauffen, the pulp has the following composition per 100
parts:

    Fatty matter                     2.407
    Glucose                         33.92
    Inverted sugar                   7.825
    Coloring matter and free acids   1.300
    Albuminous matter                5.240
    Gummy matter                    19.109
    Cellulose                        8.921
    Lignose                         17.195
    Salts                            4.080
                                   -------
    Total                          100.000

The salient point of these analytical results is the enormous quantity
of matter (nearly 60 per cent.) formed almost exclusively by sugar. It
is not surprising, from this that this product constitutes a food both
agreeable and useful.

An analysis of the entire seed, made by the same chemist, has given
the following results:

    Solid fatty matter                     21.145
    Unreduced sugar                         6.183
    Undetermined matters                    5.510
    Gummy          "                       10.272
    Albuminoid     "                       24.626
    Cellulosic     "                        5.752
    Lignose and losses                     20.978
    Salts                                   5.534
                                          -------
    Total                                 100.000

The presence in these seeds of a large quantity of fatty matters and
sugar, and especially of albuminoid matters (very nutritive), largely
justifies the use made of them as a food. The innate instinct of the
savage peoples of Africa has thus anticipated the data of
science.--_La Nature._

       *       *       *       *       *




THE HEIGHT OF SUMMER CLOUDS.


A knowledge of the heights and movements of the clouds is of much
interest to science, and of especial importance in the prediction of
weather. The subject has therefore received much attention during
recent years from meteorologists, chiefly in this country and in
Sweden. In the last published report of the Meteorological Council for
1885-86 will be found an account of the steps taken by that body to
obtain cloud photographs; and in the _Meteorologische Zeitschrift_ for
March last, M.M. Ekholm and Hagstrom have published an interesting
summary of the results of observations made at Upsala during the
summers of 1884-85. They determined the parallax of the clouds by
angular measurements made from two stations at the extremities of a
base of convenient length and having telephonic connection. The
instruments used were altazimuths, constructed under the direction of
Prof. Mohn, specially for measuring the parallax of the aurora
borealis. A full description of these instruments and of the
calculations will be found in the _Acta Reg Soc. Sc. Ups._, 1884. The
results now in question are based upon nearly 1,500 measurements of
_heights_; the _motions_ will form the subject of a future paper. It
was found that clouds are formed at all levels, but that they occur
most frequently at certain elevations or stages. The following are,
approximately, the mean heights, in feet, of the principal forms:
Stratus, 2,000; nimbus, 5,000; cumulus (base) 4,500, (summit) 6,000;
cumulo-stratus (base), 4,600; "false-cirrus" (a form which often
accompanies the cumulo-stratus), 12,800; cirro cumulus, 21,000;
cirrus, 29,000 (the highest being 41,000). The maximum of cloud
frequency was found to be at levels of 2,300 and 5,500 feet.

Generally speaking, all the forms of cloud have a tendency to rise
during the course of the day; the change, excepting for the cumulus
form, amounting to nearly 6,500 feet. In the morning, when the cirrus
clouds are at their lowest level, the frequency of their lowest
forms--the cirro-cumulus--is greatest; and in the evening, when the
height of the cirrus is greatest, the frequency of its highest
forms--the cirro-stratus--is also greatest. With regard to the
connection between the character of the weather and the height of the
clouds, the heights of the bases of the cumulus are nearly constant in
all conditions. The summits, however, are lowest in the vicinity of a
barometric maximum. They increase in the region of a depression, and
attain their greatest height in thunderstorms, the thickness of the
cumulo stratus stretching sometimes for several miles. The highest
forms of clouds appear to float at their lowest levels in the region
of a depression. The forms of clouds are identical in all parts of the
world, as has been shown in papers lately read by the Hon. R.
Abercromby before the English and Scottish Meteorological
Societies.--_Nature_.

       *       *       *       *       *




ON THE CAUSE OF IRIDESCENCE IN CLOUDS.

By G. JOHNSTONE STONEY.


When the sky is occupied by light cirro-cumulus cloud, an optical
phenomenon of the most delicate beauty sometimes presents itself, in
which the borders of the clouds and their lighter portions are
suffused with soft shades of color like those of mother-of-pearl,
among which lovely pinks and greens are the most conspicuous. Usually
these colors are distributed in irregular patches, just as in
mother-of-pearl; but occasionally they are seen to form round the
denser patches of cloud a regular colored fringe, in which the several
tints are arranged in stripes following the sinuosities of the outline
of the cloud.

I cannot find in any of the books an explanation of this beautiful
spectacle, all the more pleasing because it generally presents itself
in delightful summer weather. It is not mentioned in the part of
Moigno's great _Repertoire d'Optique_ which treats of meteorological
optics, nor in any other work which I have consulted. It seems
desirable, therefore, to make an attempt to search out what appears to
be its explanation.

At the elevation in our atmosphere at which these delicate clouds are
formed the temperature is too low, even in midsummer, for water to
exist in the liquid state; and accordingly, the attenuated vapor from
which they were condensed passed at once into a solid form. They
consist, in fact, of tiny crystals of ice, not of little drops of
water. If the precipitation has been hasty, the crystals will, though
all small, be of many sizes jumbled together, and in that case the
beautiful optical phenomenon with which we are now dealing will not
occur. But if the opposite conditions prevail (which they do on rare
occasions), if the vapor had been evenly distributed, and if the
precipitation took place slowly, then will the crystals in any one
neighborhood be little ice crystals of nearly the same form and size,
and from one neighborhood to another they will differ chiefly in
number and size, owing to the process having gone on longer or taken
place somewhat faster, or through a greater depth, in some
neighborhoods than others. This will give rise to the patched
appearance of the clouds which prevails when this phenomenon presents
itself. It also causes the tiny crystals, of which the cloud consists,
to grow larger in some places than others.

Captain Scoresby, in his "Account of the Arctic Regions," gives the
best description of snow crystals formed at low temperatures with
which I am acquainted. From his observations it appears--(a) that
when formed at temperatures several degrees below the freezing point,
the crystals, whether simple or compound, are nearly all of
symmetrical forms; (b) that thin tabular crystals are extremely
numerous, consisting either of simple transverse slices of the
fundamental hexagon or, more frequently, of aggregations of these
attached edgewise and lying in one plane; and (c) that, according as
atmospheric conditions vary, one form of crystal or another largely
preponderates. A fuller account of these most significant observations
is given in the appendix to this paper.

Let us then consider the crystals in any one neighborhood in the sky,
where the conditions that prevail are such as to produce lamellar
crystals of nearly the same thickness. The tabular plates are
subsiding through the atmosphere--in fact, falling toward the earth.
And although their descent is very slow, owing to their minute size,
the resistance of the air will act upon them as it does upon a falling
feather. It will cause them, if disturbed, to oscillate before they
settle into that horizontal position which flat plates finally assume
when falling through quiescent air. We shall presently consider what
the conditions must be, in order that the crystals may be liable to be
now and then disturbed from the horizontal position. If this
occasionally happens, the crystals will keep fluttering, and at any
one moment some of them will be turned so as to reflect a ray from the
sun to the eye of the observer from the flat surface of the crystal
which is next him. Now, if the conditions are such as to produce
crystals which are plates with parallel faces, and as they are also
transparent, part only of the sun's ray that reaches the front face of
the crystal will be reflected from it; the rest will enter the
crystal, and, falling on the parallel surface behind, a portion will
be there reflected, and passing out through the front face, will also
reach the eye of the observer.

These two portions of the ray--that reflected from the front face and
that reflected from the back--are precisely in the condition in which
they can interfere with one another, so as to produce the splendid
colors with which we are familiar in soap bubbles. If the crystals are
of diverse thicknesses, the colors from the individual crystals will
be different, and the mixture of them all will produce merely white
light; but if all are nearly of the same thickness, they will transmit
the same color toward the observer, who will accordingly see this
color in the part of the cloud occupied by these crystals. The color
will, of course, not be undiluted; for other crystals will send
forward white light, and this, blended with the colored light, will
produce delicate shades in cases where the corresponding colors of a
soap bubble would be vivid.

We have now only to explain how it happens that on very rare occasions
the colors, instead of lying in irregular patches, form definite
fringes round the borders of the cloudlets. The circumstances that
give rise to this special form of the phenomenon appear to be the
following: While the cloud is in the process of growth (that is, so
long as the precipitation of vapor into the crystalline state
continues to take place), so long will the crystals keep augmenting.
If, then, a cloudlet is in the process of formation, not only by the
springing up of fresh crystals around, but also by the continued
growth of the crystals within it, then will that patch of cloud
consist of crystals which are largest in its central part, and
gradually smaller as their situation approaches the outside. Here,
then, are conditions which will produce one color round the margin of
the cloud, and that color mixed with others, and so giving rise to
other tints, farther in. In this way there comes into existence that
iris-like border which is now and then seen.

The occasional upsetting of the crystals, which is required to keep
them fluttering, may be produced in any of three ways. The cloudlets
may have been formed from the blending together of two layers of air
saturated at different temperatures, and moving with different
velocities or in different directions. Where these currents intermix,
a certain amount of disturbance will prevail, which, if sufficiently
slight, would not much interfere with the regularity of the crystals,
and might yet be sufficient to occasion little draughts, which would
blow them about when formed. Or, if the cold layer is above, and if it
is in a sufficient degree colder, there need not be any previous
relative motion of the two layers; the inevitable convection currents
will suffice. Another, and probably the most frequent, cause for
little breezes in the neighborhood of the cloudlets is that when the
cloudlets are formed they immediately absorb the heat of the sun in a
way that the previously clear air had not done. If they absorb enough,
they will rise like feeble balloons, and slight return currents will
travel downward round their margins, throwing all crystals in that
situation into disorder.

I do not include among the causes which may agitate the crystals
another cause which must produce excessively slight currents of air,
namely, that arising from the subsidence of the cloudlets owing to
their weight. The crystals will fall faster wherein cloud masses than
in the intervening portions where the cloud is thinner. But the
subsidence itself is so slow that any relative motions to which
differences in the rate of subsidence can give rise are probably too
feeble to produce an appreciable effect. Of course, in general, more
than one of the above causes will concur; and it is the resultant of
the effects which they would have separately produced that will be
felt by the crystals.

If the precipitation had taken place so very evenly over the sky that
there were no cloudlets formed, but only one uniform veil of haze,
then the currents which would flutter the crystals may be so entirely
absent that the little plates of crystals can fixedly assume the
horizontal position which is natural to them. In this event the cloud
will exhibit no iridescence, but, instead of it, a vertical circle
through the sun will present itself. This, on some rare occasions, is
a feature of the phenomenon of parhelia.

It thus appears that the occasional iridescence of cirrus clouds is
satisfactorily accounted for by the concurrence of conditions, each of
which is known to have a real existence in nature....--_Phil. Mag.,
July 1887._

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