[Illustration]

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. 

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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

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THE BRITISH ASSOCIATION. 

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

The fifty-seventh annual meeting of the British Association was openedon Wednesday evening, Aug. 31, 1887, at Manchester, by an address fromthe president, Sir H. E. Roscoe, M. P. This was delivered in the FreeTrade Hall. The chair was occupied by Professor Williamson, who wassupported by the Bishop of Manchester, Sir F. Bramwell, ProfessorGamgee, Professor Milnes Marshall, Professor Wilkins, Professor BoydDawkins, Professor Ward, and many other distinguished men. A telegramwas 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 theaudience, was heartily applauded. 

The president, in his inaugural address, said Manchester, distinguishedas the birthplace of two of the greatest discoveries of modern science, welcomed the visit of the British Association for the third time. Thosediscoveries 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 aboutthe year 1842 by Dr. Joule. While the place suggested these reminders, the time, the year of the Queen's jubilee, excited a feeling ofthankfulness that they had lived in an age which had witnessed anadvance in our knowledge of nature and a consequent improvement in thephysical, moral, and intellectual well-being of the people hithertounknown. 

PROGRESS OF CHEMISTRY. 

A sketch of that progress in the science of chemistry alone would bethe subject of his address. The initial point was the views of Daltonand his contemporaries compared with the ideas which now prevail; andhe (the president) examined this comparison by the light which theresearch of the last fifty years had thrown on the subject of theDaltonian 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 theconclusion that the diameter of an atom of oxygen or nitrogen was theten-millionth part of a centimeter. With the highest known magnifyingpower 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 ahundred millions of atoms of oxygen and nitrogen. As to theindivisibility of the atom, the space of fifty years had completelychanged the face of the inquiry. Not only had the number of distinct, well-established elementary bodies increased from fifty-three in 1837to seventy in 1887, but the properties of these elements had beenstudied, and were now known with a degree of precision then undreamtof. Had the atoms of our present elements been made to yield? To thisa negative answer must undoubtedly be given, for even the highest ofterrestrial temperatures, that of the electric spark, had failed toshake any one of these atoms in two. This was shown by the resultswith which spectrum analysis had enriched our knowledge. Terrestrialanalysis had failed to furnish favorable evidence; and, turning to thechemistry of the stars, the spectra of the white, which werepresumably the hottest stars, furnished no direct evidence that adecomposition of any terrestrial atom had taken place; indeed, welearned that the hydrogen atom, as we know it here, can endureunscathed the inconceivably fierce temperature of stars presumablymany times more fervent than our sun, as Sirius and Vega. It wastherefore no matter for surprise if the earth-bound chemist should forthe present continue to regard the elements as the unalterablefoundation stones upon which his science is based. 

ATOMIC MOTION. 

Passing to the consideration of atoms in motion, while Dalton andGraham indicated that they were in a continual state of motion, wewere indebted to Joule for the first accurate determination of therate of that motion. Clerk-Maxwell had calculated that a hydrogenmolecule, moving at the rate of seventy miles per minute, must, in onesecond of time, knock against others no fewer than eighteen thousandmillion times. This led to the reflection that in nature there is nosuch thing as great or small, and that the structure of the smallestparticle, invisible even to our most searching vision, may be ascomplicated as that of any one of the heavenly bodies which circleround our sun. How did this wonderful atomic motion affect theirchemistry?

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 modernscience, namely, the determination of the mechanical equivalent ofheat. Every change in the arrangement of the particles he found wasaccompanied by a definite evolution or an absorption of heat. Heat wasevolved by the clashing of the atoms, and this amount was fixed anddefinite. Thus to Joule we owe the foundation of chemical dynamics andthe basis of thermal chemistry. It was upon a knowledge of the mode ofarrangement of atoms, and on a recognition of their distinctiveproperties, that the superstructure of modern organic chemistryrested. We now assumed on good grounds that the atom of each elementpossessed distinct capabilities of combination. The knowledge of themode in which the atoms in the molecule are arranged had given toorganic chemistry an impetus which had overcome many experimentalobstacles, and organic chemistry had now become synthetic. 

Liebig and Wohler, in 1837, foresaw the artificial production in thelaboratories of all organic substances so far as they did notconstitute a living organism. And after fifty years their prophecy hadbeen fulfilled, for at the present time we could prepare an artificialsweetening principle, an artificial alkaloid, and salacine. 

SYNTHESIS. 

We know now that the same laws regulate the formation of chemicalcompounds in both animate and inanimate nature, and the chemist onlyasked for a knowledge of the constitution of any definite chemicalcompounds found in the organic world in order to be able to promise toprepare it artificially. Seventeen years elapsed between Wohler'sdiscovery of the artificial production of urea and the next realsynthesis, which was accomplished by Kolbe, when in 1845 he preparedacetic acid from its elements. Since then a splendid harvest ofresults had been gathered in by chemists of all nations. In 1834 Dumasmade known the law of substitution, and showed that an exchange couldtake place between the constituent atoms in a molecule, and upon thislaw depended in great measure the astounding progress made in the widefield of organic synthesis. 

Perhaps the most remarkable result had been the production of anartificial sweetening agent, termed saccharin, 250 times sweeter thansugar, prepared by a complicated series of reactions from coal tar. These discoveries were not only of scientific interest, for they hadgiven rise to the industry of coal tar colors, founded by ourcountryman Perkin, the value of which was measured by millionssterling annually. Another interesting application of syntheticchemistry to the needs of everyday life was the discovery of a seriesof valuable febrifuges, of which antipyrin might be named as the mostuseful. 

An important aspect in connection with the study of these bodies wasthe physiological value which had been found to attach to theintroduction of certain organic radicals, so that an indication wasgiven of the possibility of preparing a compound which will possesscertain desired physiological properties, or even to foretell the kindof action which such bodies may exert on the animal economy. But nowthe question might well be put, Was any limit set to this syntheticpower of the chemist? Although the danger of dogmatizing as to theprogress of science had already been shown in too many instances, yetone could not help feeling that the barrier between the organized andunorganized worlds was one which the chemist at present saw no chanceof breaking down. True, there were those who professed to foresee thatthe day would arrive when the chemist, by a succession of constructiveefforts, might pass beyond albumen, and gather the elements oflifeless matter into a living structure. Whatever might be saidregarding this from other standpoints, the chemist could only say thatat present no such problem lay within his province. 

Protoplasm, with which the simplest manifestations of life areassociated, was not a compound, but a structure built up of compounds. The chemist might successfully synthesize any of its componentmolecules, but he had no more reason to look forward to the syntheticproduction of the structure than to imagine that the synthesis ofgallic acid led to the artificial production of gall nuts. Althoughthere was thus no prospect of effecting a synthesis of organizedmaterial, yet the progress made in our knowledge of the chemistry oflife during the last fifty years had been very great, so much soindeed that the sciences of physiological and of pathologicalchemistry 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 hadmarked the recent study of the relations between the vital phenomenaand those of the inorganic world. No portion of the science ofchemistry was of greater interest or greater complexity than thatwhich, bearing on the vital functions both of plants and of animals, endeavored to unravel the tangled skein of the chemistry of life, andto explain the principles according to which our bodies live, andmove, and have their being. If, therefore, in the less complicatedproblems with which other portions of our science have to deal, wefound ourselves often far from possessing satisfactory solutions, wecould not be surprised to learn that with regard to the chemistry ofthe living body--whether vegetable or animal--in health or disease, wewere still farther from a complete knowledge of phenomena, even thoseof fundamental importance. 

Liebig asked if we could distinguish, on the one hand, between thekind of food which goes to create warmth and, on the other, that bythe oxidation of which the motions and mechanical energy of the bodyare kept up. He thought he was able to do this, and he divided foodinto two categories. The starchy or carbo-hydrate food was that, saidhe, which by its combustion provided the warmth necessary for theexistence and life of the body. The albuminous or nitrogenousconstituents of our food, the flesh meat, the gluten, the casein outof which our muscles are built up, were not available for the purposeof creating warmth, but it was by the waste of those muscles that themechanical energy, the activity, the motions of the animal aresupplied. 

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

What did modern research say to this question? Could it be brought tothe 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; wecould measure this work in terms of our mechanical standard, inkilogramme-meters or foot-pounds. We could next determine what was thedestruction of nitrogenous tissue at rest and under exercise by theamount of nitrogenous material thrown off by the body. And here wemust remember that these tissues were never completely burned, so thatfree nitrogen was never eliminated. If now we knew the heat value ofthe burned muscle, it was easy to convert this into its mechanicalequivalent and thus measure the energy generated. What was the result?

Was the weight of muscle destroyed by ascending the Faulhorn or byworking on the treadmill sufficient to produce on combustion heatenough when transformed into mechanical exercise to lift the body upto 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 casethat the actual energy developed was twice as great as that whichcould possibly be produced by the oxidation of the nitrogenousconstituents eliminated from the body during twenty-four hours. Thatwas to say, taking the amount of nitrogenous substance cast off fromthe body, not only while the work was being done, but duringtwenty-four hours, the mechanical effect capable of being produced bythe muscular tissue from which this cast-off material was derivedwould only raise the body half way up the Faulhorn, or enable theprisoner to work half his time on the treadmill. Hence it was clearthat Liebig's proposition was not true. 

The nitrogenous constituents of the food did doubtless go to repairthe waste of muscle, which, like every other portion of the body, needed renewal, while the function of the non-nitrogenous food was notonly to supply the animal heat, but also to furnish, by its oxidation, the muscular energy of the body. We thus came to the conclusion thatit was the potential energy of the food which furnished the actualenergy of the body, expressed in terms either of heat or of mechanicalwork. 

But there was one other factor which came into play in this questionof mechanical energy, and must be taken into account; and this factorwe were as yet unable to estimate in our usual terms. It concerned theaction of the mind on the body, and although incapable of exactexpression, exerted none the less an important influence on thephysics and chemistry of the body, so that a connection undoubtedlyexisted between intellectual activity or mental work and bodilynutrition. What was the expenditure of mechanical energy whichaccompanied mental effort was a question which science was probablyfar from answering; but that the body experienced exhaustion as theresult 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 chemiston an entirely new basis. 

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

It was to our English agricultural chemists, Lawes and Gilbert, thatwe owed the complete experimental proof required, and this experimentwas long and tedious, for it had taken forty-four years to give adefinite reply. 

At Rothamsted a plot was set apart for the growth of wheat. Forforty-four successive years that field had grown wheat without theaddition of any carbonized manure, so that the only possible sourcefrom which the plant could obtain the carbon for its growth was theatmospheric carbonic acid. The quantity of carbon which on an averagewas removed in the form of wheat and straw from a plot manured onlywith mineral matter was 1, 000 lb. , while on another plot, for which anitrogenous manure was employed, 1, 500 lb. More carbon was annuallyremoved, or 2, 500 lb. Of carbon were removed by this crop annuallywithout the addition of any carbonaceous manure. So that Liebig'sprevision had received a complete experimental verification. 

CHEMICAL PATHOLOGY. 

Touching us as human beings even still more closely than the foregoingwas the influence which chemistry had exerted on the science ofpathology, and in no direction had greater progress been made than inthe study of micro-organisms in relation to health and disease. In thecomplicated chemical changes to which we gave the names offermentation and putrefaction, Pasteur had established the fundamentalprinciple that these processes were inseparately connected with thelife of certain low forms of organisms. Thus was founded the scienceof bacteriology, which in Lister's hands had yielded such splendidresults in the treatment of surgical cases, and in those of Klebs, Koch, and others, had been the means of detecting the cause of manydiseases both in man and animals, the latest and not the leastimportant of which was the remarkable series of successful researchesby Pasteur into the nature and mode of cure of that most dreadful ofmaladies, hydrophobia. The value of his discovery was greater thancould be estimated by its present utility, for it showed that it mightbe possible to avert other diseases besides hydrophobia by theadoption of a somewhat similar method of investigation and oftreatment. 

Here it might seem as if we had outstepped the boundaries ofchemistry, and had to do with phenomena purely vital. But recentresearch indicated that this was not the case, and pointed to theconclusion that the microscopist must again give way to the chemist, and that it was by chemical rather than biological investigation thatthe causes of diseases would be discovered, and the power of removingthem obtained. For we learned that the symptoms of infective diseaseswere no more due to the microbes which constituted the infection thanalcoholic intoxication was produced by the yeast cell, but that thesesymptoms were due to the presence of definite chemical compounds, theresult of the life of these microscopic organisms. So it was to theaction of these poisonous substances formed during the life of theorganism, rather than to that of the organism itself, that the specialcharacteristics of the disease were to be traced, for it had beenshown that the disease could be communicated by such poisons in theentire absence of living organisms. 

Had time permitted, he would have wished to have illustrated thedependence of industrial success upon original investigation, and tohave pointed out the prodigious strides which chemical industry inthis 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, bothin its artistic and useful aspects, owed to chemistry, and thereforehow essential a knowledge of the principles of the science was to allwho had the industrial progress of the country at heart. The countrywas now beginning to see that if she was to maintain her commercialand industrial supremacy, the education of her people from top tobottom must be carried out on new lines. The question how this couldbe most safely and surely accomplished was one of transcendentnational importance, and the statesman who solved this educationalproblem would earn the gratitude of generations yet to come. 

In welcoming the unprecedentedly large number of foreign men ofscience who had on this occasion honored the British Association bytheir presence, he hoped that that meeting might be the commencementof an international scientific organization, the only means nowadaysexisting of establishing that fraternity among nations from whichpolitics appeared to remove them further and further, by absorbinghuman powers and human work, and directing them to purposes ofdestruction. It would indeed be well if Great Britain, which hadhitherto taken the lead in so many things that are great and good, should now direct her attention to the furthering of internationalorganizations of a scientific nature. A more appropriate occasion thanthe present meeting could perhaps hardly be found for the inaugurationof such a movement. But whether this hope were realized or not, theyall united in that one great object, the search after truth for itsown sake, and they all, therefore, might join in re-echoing the wordsof Lessing: "The worth of man lies not in the truth which hepossesses, or believes that he possesses, but in the honest endeavorwhich he puts forth to secure that truth; for not by the possession oftruth, but by the search after it, are the faculties of man enlarged, and in this alone consists his ever-growing perfection. Possessionfosters content, indolence, and pride. If God should hold in his righthand all truth, and in his left hand the ever-active desire to seektruth, though with the condition of perpetual error, I would humblyask 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 thepresident, on the motion of the Mayor of Manchester, seconded byProfessor Asa Gray, of Harvard College. The president mentioned thatthe number of members is already larger than at any previous annualmeeting, namely, 3, 568, including eighty foreigners. 

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THE CRIMSON LINE OF PHOSPHORESCENT ALUMINA. 

Crookes has presented to the Royal Society a paper on the coloremitted by pure alumina when submitted to the electric discharge _invacuo_, in answer to the statements of De Boisbaudran. In 1879 he hadstated that "next to the diamond, alumina, in the form of ruby, isperhaps the most strikingly phosphorescent stone I have examined. Itglows with a rich, full red; and a remarkable feature is that it is oflittle consequence what degree of color the earth or stone possessesnaturally, the color of the phosphorescence is nearly the same in allcases; chemically precipitated amorphous alumina, rubies of a palereddish yellow, and gems of the prized 'pigeon's blood' color glowingalike in the vacuum. " These results, as well as the spectra obtained, he stated further, corroborated Becquerel's observations. Inconsequence of the opposite results obtained by De Boisbaudran, Crookes has now re-examined this question with a view to clear up themystery. On examining a specimen of alumina prepared from tolerablypure aluminum sulphate, shown by the ordinary tests to be free fromchromium, the bright crimson line, to which the red phosphorescentlight is due, was brightly visible in its spectrum. The aluminumsulphate was then, in separate portions, purified by various processesespecially adapted to separate from it any chromium that might bepresent; the best of these being that given by Wohler, solution inexcess of potassium hydrate and precipitation of the alumina by acurrent of chlorine. The alumina filtered off, ignited, and tested ina radiant matter tube gave as good a crimson line spectrum as did thatfrom 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 beingsuppressed by an accompanying earth which concentrates toward one endof the fractionations; (2) the crimson line is not due to alumina, butis due to the presence of an accompanying earth concentrating towardthe other end of the fractionations; (3) the crimson line belongs toalumina, but its full development requires certain precautions to beobserved in the time and intensity of ignition, degree of exhaustion, or its absolute freedom from alkaline and other bodies carried down byprecipitated alumina and difficult to remove by washing; experiencenot having yet shown which of these precautions are essential to thefull development of the crimson line and which are unessential; and(4) the earth alumina is a compound molecule, one of its constituentmolecules giving the crimson line. According to this hypothesis, alumina would be analogous to yttria. "--_Nature. _

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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 ofcarbonic acid in the air, employing Van Nuys' apparatus, [1] recentlydescribed in this journal. These estimations were made in theUniversity Park, one-half mile from the town of Bloomington. The parkis hilly, thinly shaded, and higher than the surrounding country. Theformation is sub-carboniferous and altitude 228 meters. There are nolowlands 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 100meters from any of the university buildings. The number of volumes ofcarbonic 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 ofair is 28. 16, the maximum number is 28. 98, and the minimum 27. 34. These results agree with estimations made within the last ten orfifteen years. Reiset[2] made a great number of estimations fromSeptember 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, theaverage of which is 29. 78. The average of Schultze's[4] estimations is29 2. The results of estimations of carbonic acid in the air, madeunder the supervision of Munz and Aubin[5] in October, November, andDecember, 1882, at the stations where observations were made of thetransit of Venus by astronomers sent out by the French government, yield the average, for all stations north of the equator to latitude29° 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 ofClaesson'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 ofestimations of carbonic acid of the air of various parts of the globe, by the employment of apparatus with which errors are avoided, that thequantity of carbonic acid is subject to slight variation, and not, asstated in nearly all text books of science, from 4 to 6 volumes in10, 000 volumes of air; and it is further apparent that the law ofSchloesing[7] holds good. By this law the carbonic acid of anatmosphere in contact with water containing calcium or magnesiumcarbonate in solution is dissolved according to the tension of thecarbonic acid; that is, by an increased quantity its tensionincreases, and more would pass in solution in the form ofbicarbonates. On the other hand, by diminishing the quantity ofcarbonic acid in the atmosphere, some of the bicarbonates woulddecompose 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 ofthe English Channel lead Schloesing[9] to conclude that the carbonicacid combined with normal carbonates, forming bicarbonates, dissolvedin the water of the globe is ten times greater in quantity than thatof the atmosphere, and on account of this available carbonic acid, ifthe atmosphere should be deprived of some of its carbonic acid, theloss would soon be supplied. 

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

As, in nearly all of the methods which were employed for estimatingcarbonic acid in the air, provision is not made for the exclusion ofair not measured containing carbonic acid from the alkaline fluidbefore titrating or weighing, the results are generally too high andshow a far greater variation than is found by more exact methods. Forexample, Gilm[10] found from 36 to 48 volumes; Levy's[11] average is34 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 tovariation, yet the results of Reiset's and Schultze's estimations goto 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. _

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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 theirmilitary dietaries, and in England several large contract orderscannot yet be filled, owing to insufficiency of supply, while awell-known cocoa manufacturing firm has taken up the preparation ofkola 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' Clubof Cleveland, O. 

Notwithstanding the wonderful development of our steel industries inthe last decade, the improvements in the modes of manufacture, and theundoubted strength of the metal under certain circumstances, nevertheless we find that steel has not altogether met therequirements of engineers as a structural material. Although itsbreaking strain and elastic limit are higher than those of wroughtiron, the latter metal is frequently preferred and selected fortensile members, even when steel is used under compression in the samestructure. The Niagara cantilever bridge is a notable instance of thispractice. When steel is used in tension its working strains are notallowed to be over fifty per cent. Above those adopted for wroughtiron. 

The reasons for the suspicion with which steel is regarded are wellunderstood. Not only is there a lack of uniformity in the product, butapparently the same steel will manifest very different results underslight provocation. Steel is very sensitive, not only to slightchanges 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 wouldseriously affect the efficiency of the metal in service. 

Among the steels, those that are softer are more serviceable andreliable than the harder ones, especially whereever shocks andconcussions or rapidly alternating strains are to be endured. In otherwords, the more nearly steel resembles good wrought iron, the morecertain it is to render lasting service when used within appropriatelimits of strain. Indeed, a wrought iron of fine quality is bettercalculated to endure fatigue than any steel. This is particularlynoticeable in steam hammer pistons, propeller shafts, and railroadaxles. A better quality of wrought iron, therefore, has long been adesideratum, and it appears now that it has at last been found. 

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

The process of manufacture is briefly as follows: The pig metal, afterbeing melted in a cupola and tapped into a discharging ladle, isdelivered into a Bessemer converter, in which the metal is largelyrelieved of its silicon, sulphur, carbon, etc. , by the ordinarypneumatic process. At the end of the blow the converter is turned downand its contents discharged into a traveling ladle, and quicklydelivered to machines called ballers, which are rotary reverberatoryfurnaces, each revolving on a horizontal axis. In the baller the ironis very soon made into a ball without manual aid. It is then liftedout by means of a suspended fork and carried to a Winslow squeezer, where the ball is reduced to a roll twelve inches in diameter. Thenceit is taken to a furnace for a wash heat, and finally to the mucktrain. 

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

The baller is a bulging cylinder having hollow trunnions through whichthe flame passes. The cylinder is lined with fire brick, and this inturn is covered with a suitable refractory iron ore, from eight to teninches thick, grouted with pulverized iron ore, forming a bottom, asin the common puddling furnace. The phosphorus of the iron, whichcannot be eliminated in the intense heat of the converter, is, however, reduced to a minimum in the baller at a much lowertemperature and on the basic lining. The process wastes the liningvery slightly indeed. As many as sixty heats have been taken off insuccession without giving the lining any attention. The absence of anyreagent leaves the iron simply pure and homogeneous to a degree neverrealized in muck bars made by the old puddling process. Thus theexpense of a reheating and rerolling to refine the iron is obviated. It was such iron as here results that Bessemer, in his earlyexperiments, was seeking to obtain when he was diverted from hispurpose by his splendid discoveries in the art of making steel. Soeffective is the new process, that even from the poorest grades of pigmay be obtained economically an iron equal in quality to the refinedirons made from the best pig by the ordinary process of puddling. 

Numerous tests of the Chapin irons have been made by competent anddisinterested parties, and the results published. The samples herenoted 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 andhalf. 

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 beabout 38, 000, 40, 000, and 42, 000 respectively, or the gain of the ironin tensile strength by the Chapin process is about fifty per cent. Notonly so, but these irons made in this manner from inferior pig show ahigher elastic limit and breaking strain than are commonly specifiedfor refined iron of best quality. The usual specifications are forrefined 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. Abovethose 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 ofthe pig iron from which it can be made. When made from the best pigmetal its breaking and elastic limits will probably reach 70, 000 and40, 000 pounds respectively. If so, it will be a safer material thansteel under the same working strains, owing to its greater resilience. 

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

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

 * * * * *

CELLULOID. 

Professor Sadler, of the University of Pennsylvania, has lately givenan account of the development and method of the manufacture ofcelluloid. Alexander Parkes, an Englishman, invented this remarkablesubstance in 1855, but after twelve years quit making it because ofdifficulties in manipulation, although he made a fine display at theParis Exposition of 1867. Daniel Spill, also of England, beganexperiments two years after Parkes, but a patent of his for dissolvingthe nitrated wood fiber, or "pyroxyline, " in alcohol and camphor wasdecided by Judge Blatchford in a suit brought against the CelluloidManufacturing Company to be valueless. No further progress was madeuntil the Hyatt Brothers, of Albany, N. Y. , discovered that gumcamphor, when finely divided, mixed with the nitrated fiber and thenheated, is a perfect solvent, giving a homogeneous and plastic mass. American patents of 1870 and 1874 are substantially identical withthose now in use in England. In France there is only one factory, andthere is none elsewhere on the Continent, one in Hanover having beengiven up on account of the explosive nature of the stuff. In thiscountry pure cellulose is commonly obtained from paper makers, in theform of tissue paper, in wide rolls; this, after being nitrated by abath of mixed nitric and sulphuric acids, is thoroughly washed andpartially dried. Camphor is then added, and the whole is groundtogether and thoroughly mixed. At this stage coloring matter may beput in. A little alcohol increases the plasticity of the mass, whichis then treated for some time to powerful hydraulic pressure. Thencomes breaking up the cakes and feeding the fragments between heatedrolls, by which the amalgamation of the whole is completed. Itsperfect plasticity allows it to be rolled into sheets, drawn intotubes, 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 torender valuable service in the champagne industry. The apparentlysimple operation of confining the carbonic acid due to fermentation ina bottle in order to blow the cork from the latter with force at agiven moment is not always successful, notwithstanding the skill andexperience of the manipulator. How could it be otherwise?

Everything connected with the production of champagne wine was butrecently unknown and unexplained. The proportioning of the sugaraccurately dates, as it were, from but yesterday, and the measurementof the absorbing power of wine for carbonic acid has but just enteredinto practice, thanks to Mr. Salleron's absorptiometer. The realstrength of the bottles, and the laws of the elasticity of glass andits variation with the temperature, are but little known. Finally, thephysical constitution of cork, its chemical composition, itsresistance to compression and the dissolving action of the wine, mustbe taken into consideration. In fact, all the elements of thedifficult problem of the manufacture of sparkling wine show that thereis an urgent necessity of introducing scientific methods into thisindustry, as without them work can now no longer be done. 

No one has had a better opportunity to show how easy it is to convertthe juice of the grape into sparkling wine through a series of simpleoperations whose details are known and accurately determined, so webelieve it our duty to recommend those of our readers who areparticularly interested in this subject to read Mr. Salleron's book onsparkling wine. We shall confine ourselves in this article to adescription of two of the apparatus invented by the author for testingthe resistance of bottles and cork stoppers. 

It is well, in the first place, to say that one of the importantelements in the treatment of sparkling wine is the normal pressurethat it is to produce in the bottles. After judicious deductions andnumerous experiments, Mr. Salleron has adopted for the normal pressureof highly sparkling wines five atmospheres at the temperature of thecellar, which does not exceed 10 degrees. But, in a defective cellar, the bottles may be exposed to frost in winter and to a temperature of25° in summer, corresponding to a tension of ten atmospheres. It maynaturally be asked whether bottles will withstand such an ordeal. Mr. Salleron has determined their resistance through the process by whichwe estimate that of building materials, viz. , by measuring the limitof their elasticity, or, in other words, the pressure under which theytake on a new permanent volume. In fact, glass must be assimilated toa perfectly elastic body; and bottles expand under the internalpressure that they support. If their resistance is insufficient, theycontinue to increase in measure as the pressure is further prolonged, and at every increase in permanent capacity, their resistancediminishes. 

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

The apparatus shown in Fig. 1 is called an elasticimeter, and permitsof a preliminary testing of bottles. The bottle to be tested is putinto the receptacle, A B, which is kept full of water, and when it hasbecome full, its neck is played between the jaws of the clamp, _p_. Upon turning the hand wheel, L, the bottle and the receptacle thatholds it are lifted, and the mouth of the bottle presses against arubber disk fixed under the support, C D. The pressure of the neck ofthe bottle against this disk is such that the closing is absolutelyhermetical. The support, C D, contains an aperture which allows theinterior of the bottle to communicate with a glass tube, _a b_, whichthus forms a prolongation of the neck of the bottle. This tube is verynarrow and is divided into fiftieths of a cubic centimeter. Amicroscope, _m_, fixed in front of the tube, magnifies the divisions, and allows the position of the level of the water to be ascertained towithin about a millionth of a cubic centimeter. 

A force and suction pump, P, sucks in air through the tube, _t_, andcompresses it through the tube, _t'_, in the copper tube, T, whichcommunicates with the glass tube, _a b_, after passing through thepressure 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 underthe support, C D, the cock, _s_, is opened and the liquid with whichthe small reservoir, R, has been filled flows through an aperture abovethe mouth of the bottle and rises in the tube, _a b_. When its levelreaches the division, O, the cock, _s_, is closed. The bottle and itsprolongation, _a b_, are now exactly full of water without any airbubbles. 

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

If the glass of the bottle has undergone no permanent deformation, thelevel will rise exactly to the zero mark, and denote that the bottlehas supported the test without any modification of its structure. Butif, on the contrary, the level does not return to the zero mark, thelimit of the glass's elasticity has been extended, its molecules havetaken on a new state of equilibrium, and its resistance hasdiminished, and, even if it has not broken, it is absolutely certainthat it has lost its former resistance and that it presents noparticular guarantee of strength. 

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

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

In addition, the elasticimeter is capable of giving other and no lessuseful data. It permits of comparing the resistance of bottles and ofclassifying them according to the degree of such resistance. Afternumerous experiments, it has been found that first class bottleseasily 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 formerexclusively. 

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

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

In order to explain wherein resides the quality of cork, it isnecessary to refer to a chemical analysis of it. In cork bark there is70 per cent. Of suberine, which is soluble in alcohol and ether, andis plastic, ductile, and malleable under the action of humid heat. Mixed with suberine, cerine and resin give cork its insolubility andinalterability. These substances are soluble in alcohol and ether, butinsoluble in water. 

According to the origin of cork, the wax and resin exist in it in veryvariable proportion. The more resinous kinds resist the dissolvingaction of wine better than those that are but slightly resinous. Thelatter soon become corroded and spoiled by wine. An attempt has oftenbeen made, but without success, to improve poor corks by impregnatingthem with the resinous principle that they lack. 

Various other processes have been tried without success, and so itfinally became necessary simply to separate the good from the badcorks by a practical and rapid operation. A simple examination doesnot suffice. Mr. Bouché has found that corks immersed in water finallybecame covered with brown spots, and, by analogy, in order to testcorks, he immersed them in water for a fortnight or a month. All thosethat came out spotted were rejected. Under the prolonged action ofmoisture, the suberine becomes soft, and, if it is not resinousenough, the cells of the external layer of the cork burst, the waterenters, 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 waterunder a pressure of from four to five atmospheres. By this means, thebut slightly resinous cork is quickly dissolved, so that, after a fewhours' immersion, the bad corks come out spotted and channeled as ifthey 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 aswhite 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 fortesting corks. A reservoir, A B, of tinned copper, capable of holding100 corks, is provided with a cover firmly held in place by a clamp. Into the cover is screwed a pressure gauge, M, which measures theinternal pressure of the apparatus. 

A pump, P, sucks water from a vessel through the tubulure, _t'_, andforces it through the tubulure, _t_, into the reservoir full of corks. After being submitted to a pressure of five atmospheres in thisapparatus for a few hours, the corks are verified and then sorted out. In addition to the apparatus here illustrated, there is one of largerdimensions for industrial applications. This differs from the otheronly in the arrangement of its details, and will hold as many as10, 000 corks. --_Revue Industrielle. _

 * * * * *

IMPROVED BISCUIT MACHINE. 

The accompanying illustration represents a combined biscuit cutting, scrapping, and panning machine, specially designed for running at highspeeds, and so arranged as to allow of the relative movements of thevarious parts being adjusted while in motion. The cutters or dies, mounted on a cross head working in a vertical guide frame, areoperated from the main shaft by eccentrics and vertical connectingrods, as shown. These rods are connected to the lower strap of theeccentric by long guide bolts, on which intermediate spiral springsare mounted, and by this means, although the dies are brought quicklydown to the dough, they are suffered to remain in contact therewith, under a gradually increasing pressure, for a sufficient length of timeto insure the dough being effectually stamped and completely cutthrough. 

[Illustration: IMPROVED BISCUIT MACHINE. ]

Further, the springs tend to counteract any tendency to vibration thatmight 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 apair of reversed cone drums. These, with their accompanying belt andits adjusting gear, worked by a hand wheel and traversing screw, asshown, serve to adjust the speed of the feed rollers, so as to suitthe different lengths of the intermediate travel or "skip" of thedough-carrying web. 

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

The webs for carrying forward the dough between the differentoperations pass round rollers, which are each operated by anadjustable silent clutch feed, in place of the usual ratchet and pawlmechanism. Movement is given to each feed by the connecting linksshown, to each of which motion is in turn imparted by the bell cranklever placed beside the eccentric. This lever is actuated by a crankpin on the main shaft, working into a block sliding in a slot in theshorter or horizontal arm of the lever, while a similar but adjustableblock, sliding in the vertical arm, serves to impart the motion of thelever to the system of connecting links, the adjustable block allowingof a longer or shorter stroke being given to the different feeds, asdesired. 

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

The makers, H. Edwards & Co. , Liverpool, have run one of thesemachines easily and smoothly at a hundred revolutions per minute, atwhich speed, and when absorbing about 3. 5 horse power, the outputwould equal 4, 000 small biscuits per minute. --_Industries. _

 * * * * *

IMPROVED CREAM SEPARATOR. 

A hand separator of this type was exhibited at the Royal Show atNewcastle 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 verticalsection. The drums of these machines, which make 2, 700 revolutions perminute for the large and 4, 000 for the small one, have a diameter of27 in. And 15½ in. Respectively, and are capable of extracting thecream from 220 and 115 gallons of milk per hour. These drums areformed by hydraulic pressure from one piece of sheet steel. To avoidthe possibility of the machines being overdriven, which might happenthrough the negligence of the attendant or through the governing gearon the engine failing to act, an ingenious controlling apparatus isfixed to the intermediate motion of the separator as shown in Fig. 3. This apparatus consists of a pair of governor balls pivoted near thecenter of the arms and attached to the main shaft of the intermediategear by means of a collar fixed on it. The main shaft is bored outsufficiently deep to admit a steel rod, against which bear the threeends of the governor arms. The steel rod presses against thecounterbalance, which is made exactly the right weight to withstandthe force tending to raise it, when the intermediate motion is runningat its designed speed. The forks between which the belt runs are alsoprovided with a balance weight. This brings them to the loose pulley, unless they are fixed by means of the ratchet. Should the number ofrevolutions of the intermediate increase beyond the correct amount, the extra centrifugal force imparted to the governor balls enablesthem to overcome the balance weight, and in raising this they raisethe arm. This arm striking against the ratchet detent releases thebalance weight, and the belt is at once brought on to the loosepulley. 

[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, bythree apertures, to the periphery of the drum, thus preventing themilk from striking against the cone of the drum, and from mixing withthe cream which has already been separated. The upper part of the drumis fitted with an annular flange, about 1½ in. From the top, reachingto within one-sixteenth of an inch of the periphery. After theseparation of the skim milk from the cream, the former passes behindand above this flange through the aperture, B, and is removed by meansof the tube, D, furnished with a steel tip projecting from the coverof the machine into the space between the top of the drum and theannular flange, a similar tube, F, reaching below this flange, removing the cream which collects there. The skim milk tube isprovided with a screw regulator, the function of which is to enablecream of any desired consistency to be obtained, varying with thedistance between the skim milk and cream points from the center of thedrum. Another point about these tubes is their use as elevating tubesfor the skim, milk and cream, as, owing to the velocity at which thedrum is rotating, the products can be delivered by these tubes at aheight of 8 or 10 feet above the machine if required, thus enablingscalding and cooling of either to be carried on while the separator isat work, and saving hand labor. --_Iron. _

 * * * * *

GAS FROM OIL. 

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

He said that during the last seventeen years he had devoted muchattention to the photogenic or illuminating values of differentqualities of paraffin oils in various lamps, and to the production ofpermanent illuminating gas from such oils. The earlier experimentswere directed to the employment of paraffin oils as oils, and theresults proved the great superiority of the paraffin oils asilluminating agents over vegetable and animal oils, alike forlighthouse and ordinary house service. 

The later trials were mainly concerned with the breaking up of theparaffin oils into permanent illuminating gas. Experiments were madeat low heats, medium heats, and high heats, which proved that, according to the respective qualities of the paraffin oils employed inthe trials, there was more or less tendency at the lower heats todistill oil instead of permanent gas, while at the high heats therewas a liability to decarbonize the oil and gas, and to obtain a thingas of comparatively small illuminating power. When, however, a goodcherry red heat was maintained, the oils split up in large proportioninto permanent gas of high illuminating quality, accompanied by littletarry matter, and with only a slight amount of separated carbon ordeposited soot. 

The best mode of splitting up the paraffin oils, and the specialarrangements of the retort or distilling apparatus, also formed, hesaid, an extensive inquiry by itself. In one set of trials the oil wasdistilled into gaseous vapor, and then passed through the retort. Inanother set of experiments, the oil was run into or allowed to trickleinto the retorts, while both modes of introducing the oil were triedin retorts charged with red hot coke and in retorts free from coke. 

Ultimately, it was found that the best results were obtained by themore simple arrangement of employing iron retorts at a good cherry redheat, 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 theintervention of any coke or other matter in the retorts. The paraffinoils employed in the investigations were principally: (1) Crudeparaffin oil, being the oil obtained direct from the destructivedistillation of shale in retorts; (2) green paraffin oil, which isyielded by distilling or re-running the crude paraffin oil, andremoving the lighter or more inflammable portion by fractionaldistillation; and (3) blue paraffin oil, which is obtained byrectifying the twice run oil with sulphuric acid and soda, anddistilling off the paraffin spirit, burning oil, and intermediate oil, and freezing out the solid paraffin as paraffin scale. The bestpractical trials were obtained in Pintsch's apparatus and in Keith'sapparatus. 

After describing both of these, Dr. Macadam went on to give in greatdetail the results obtained in splitting up blue paraffin oil into gasin each apparatus. He then said that these experimental resultsdemonstrated that Pintsch's apparatus yielded from the gallon of oilin one case 90. 70 cubic feet of gas of 62. 50 candle power, and in thesecond case 103. 36 cubic feet of 59. 15 candle gas, or an average of97. 03 cubic feet of 60. 82 candle power gas. 

In both cases, the firing of the retorts was moderate, though in thesecond trial greater care was taken to secure uniformity of heat, andthe oil was run in more slowly, so that there was more thoroughsplitting up of the oil into permanent gas. The gas obtained in thetwo trials was of high quality, owing to its containing a largepercentage of heavy hydrocarbons, of which there were, respectively, 39. 25 and 37. 15 per cent. , or an average of 38. 2 per cent. , while thesulphureted hydrogen was nothing, and the carbonic acid a mere trace. Besides testing the gas on the occasion of the actual trials, he hadalso examined samples of the gas which he had taken from variouscylinders in which the gas had been stored for several months under apressure of ten atmospheres, and in all cases the gas was found to bepractically equal to the quantity mentioned, and hence of a permanentcharacter. 

By using Keith's apparatus the results obtained were generally thesame, with the exception that an average of 0. 27 per cent. Of carbonicacid gas and decided proportions of sulphureted hydrogen were found tobe present in the gas. Dr. Macadam devoted some remarks to theconsideration of the question as to how far the gas obtained from theparaffin oil represented the light power of the oil itself, and thenhe proceeded to say that, taking the crude paraffin oil at 2d. Agallon, 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 apennyworth of the crude oil as gas. 

Then, taking the blue paraffin oil at 4d. Per gallon, and there being255 gallons to the ton, it was found that the cost of one ton was £45s. , 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 gasfrom a pennyworth of the blue oil. The very rich character of the oilgas rendered it unsuitable for consumption at ordinary gas jets, though it burned readily and satisfactorily at small burners notlarger than No. 1 jets. 

In practical use it would be advisable to reduce the quality byadmixture with thin and feeble gas, or to employ the oil gas simplyfor enriching inferior gases derived from the more common coals. Onthe question of dilution, he said that he preferred to use carbonicoxide and hydrogen, and most of the remainder of his paper was devotedto an explanation of the best mode of preparing those gases (watergases). 

He concluded by saying: The employment of paraffin oil for gas makinghas 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 bediscontinued and commenced again without opening, clearing outresidual products, recharging and reclosing the retorts. There isnecessarily, therefore, less labor and cost in working, and as the gasis cleaner or freer from impurities, purifying plant and material willbe correspondingly less. Oil gas is now employed for lighthouseservice in the illumination of the lanterns on Ailsa Craig and asmotive power in the gas engines connected with the fog horns atLangness and Ailsa Craig lighthouse stations. It is also used largelyin the lighting of railway carriages. Various populous places are nowintroducing oil gas for house service, and he felt sure that thesystem is one which ought to commend itself for its future developmentto the careful consideration and practical skill of the members of theGas 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 thatdistrict was the result of accident. In 1859, Messrs. Bolckow &Vaughan sank a deep well at Middlesbrough, in the hope of obtainingwater for steam and other purposes in connection with their iron worksin that town, although they had previously been informed of theprobably unsuitable character of the water if found. The bore hole wasput 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 timeone-eighth of the total salt production of Cheshire was being broughtto the Tyne for the chemical works on that river, hence the discoveryof salt instead of water was regarded by some as the reverse of adisappointment. The mode of reaching the salt rock by an ordinaryshaft, however, failed, from the influx of water being too great, andnothing more was heard of Middlesbrough salt until a dozen yearslater, when Messrs. Bell Brothers, of Port Clarence, decided to trythe practicability of raising the salt by a method detailed in thepaper. A site was selected 1, 314 yards distant from the well ofMessrs. Bolckow & Vaughan, and the Diamond Rock Boring Company wasintrusted with the work of putting down a hole in order to ascertainwhether the bed of salt extended under their land. This occupiednearly two years, when the salt, 65 feet in thickness, was reached ata depth of 1, 127 feet. Other reasons induced the owners of theClarence iron works to continue the bore hole for 150 feet below thebed of salt; a depth of 1, 342 feet from the surface was then reached. During the process of boring, considerable quantities of inflammablegas were met with, which, on the application of flame, took fire atthe surface of the water in the bore hole. The origin of this gas, inconnection 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, theprinciple being that a column of descending water should raise thebrine nearly as far as the differences of specific gravity between thetwo liquids permitted--in the present case about 997 feet. In otherwords, a column of fresh water of 1, 200 feet brought the brine towithin 203 feet of the surface. For the practical application of thissystem a hole of say 12 inches in diameter at the surface wascommenced, and a succession of wrought iron tubes put down as theboring proceeded, the pipes being of gradually decreasing diameter, until the bottom of the salt bed was reached. The portion of thisouter or retaining tube, where it passed through the bed of salt, waspierced with two sets of apertures, the upper edge of the higher setcoinciding with the top of the seam, and the other set occupying thelower portion of the tube. Within the tube so arranged, and secured atits lower extremity by means of a cavity sunk in the limestone, asecond tube was lowered, having an outer diameter from two to fourinches less than the interior diameter of the first tube. The latterserved for pumping the brine. The pump used was of the ordinary bucketand 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 ofdistribution. The bucket and clack were placed some feet below thepoint to which the brine was raised by the column of fresh waterdescending in the annulus formed between the two tubes. In commencingwork, water was let down the annulus until the cavity formed in thesalt became sufficiently large to admit of a few hours' pumping ofconcentrated brine. On the machinery being set in motion, the strongerbrine 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 waterwas of course greater than that of water partially saturated, andbeing also lighter it occupied the upper portion of the excavatedspace. The combined effect was to give the cavity the form of aninverted cone. The mode of extraction thus possessed the disadvantageof removing the greatest quantity of the mineral where it was mostwanted for supporting the roof, and had given rise to occasionalaccidents to the pipes underground. These were referred to in detail, and the question was started as to possible legal complicationsarising hereafter from new bore holes put down in close proximity tothe dividing line of different properties, the pumping of brine formedunder the conditions described presenting an altogether differentaspect from the pumping of water or natural brine. 

The second part of the paper referred to the uses to which the brinewas applied, the chief one being the manufacture of common salt. Forthis purpose the brine, as delivered from the wells, was run into alarge reservoir, where any earthy matter held in suspension wasallowed to settle. The clear solution was then run into pans sixtyfeet long by twenty feet wide by two feet deep. Heat was applied atone end by the combustion of small coal, beyond which longitudinalwalls, serving to support the pan and to distribute the heat, conducted the products of combustion to the further extremity, wherethey escaped into the chimney at a temperature of from 500° to 700°Fahr. On the surface of the heated brine, kept at 196° Fahr. , minutecubical crystals speedily formed. On the upper surface of these, othersmall cubes of salt arranged themselves in such a way that, in courseof time, a hollow inverted pyramid of crystallized salt was formed. This ultimately sank to the bottom, where other small crystals unitedwith it, so that the shape became frequently completely cubical. Everysecond day the salt was "fished" out and laid on drainers to permitthe adhering brine to run back into the pans. For the production oftable salt the boiling was carried on much more rapidly, and at ahigher temperature than for salt intended for soda manufacture. Thecrystals were very minute, and adhered together by the solidificationof the brine, effected by exposure on heated flues. For fisherypurposes the crystals were preferred very coarse in size. These wereobtained by evaporating the brine more slowly and at a still lowertemperature than when salt for soda makers was required. At theClarence works experiments had been made in utilizing surplus gas fromthe adjacent blast furnaces, instead of fuel, under the evaporatingpans, the furnaces supplying more gas than was needed for heating airand raising steam for iron making. By means of this waste heat, from200 to 300 tons of salt per week were now obtained. 

The paper concluded with some particulars of the soda industry. Thewell-known sulphuric acid process of Leblanc had stood its ground forthree-quarters of a century in spite of several disadvantages, andvarious modes of utilizing the by-products having been from time totime introduced, it had until recent years seemed too firmlyestablished 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 brineinstead of salt, and thus avoiding the cost of evaporation. Thisprocess consisted of forcing into the brine currents of carbonic acidand ammoniacal gases in such proportions as to generate bicarbonate ofammonia, which, reacting on the salt of the brine, gave bicarbonate ofsoda and chloride of ammonium. The bicarbonate was placed in areverberatory furnace, where the heat drove off the water and oneequivalent of carbonic acid, leaving the alkali as monocarbonate. NearMiddlesbrough, the only branch of industry established in connectionwith its salt trade was the manufacture of soda by an ammonia process, invented by Mr. Schloesing, of Paris. The works were carried on inconnection with the Clarence salt works. It was believed that thetotal quantity of dry soda produced by the two ammonia processes, Solvay's and Schloesing's, in this country was something under 100, 000tons per annum, but this make was considerably exceeded on theContinent. 

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COTTON INDUSTRIES OF JAPAN. 

The cotton plant principally cultivated in Japan is of the speciesknown as _Gossypium herbaceum_, resembling that of India, China, andEgypt. The plant is of short stature, seldom attaining a growth ofover two feet; the flower is deciduous, with yellow petals and purplecenter, and the staple is short, but fine. It is very widelycultivated in Japan, and is produced in thirty-seven out of theforty-four prefectures forming the empire, but the best qualities andlargest quantities are grown in the southern maritime provinces of themainland and on the islands of Kiusiu and Shikoku. Vice consulLongford, in his last report, says that the plant is not indigenous toJapan, the seed having been first imported from China in the year1558. There are now many varieties of the original species, and thecultivation of the plant varies in its details in differentlocalities. The variations are, however, mostly in dates, and thegeneral grinding principles of the several operations are nearly thesame throughout the whole country. The land best suited for cottongrowing is one of a sandy soil, the admixture of earth and sand beingin the proportion of two parts earth to one of sand. During the winterand spring months, crops of wheat or barley are raised on it, and itis when these crops have attained their full height during the monthof May that the cotton is sown. About fifty days prior to the sowing amanure is prepared consisting of chopped straw, straw ashes, greengrass, rice, bran, and earth from the bottom of the stagnant pools. These ingredients are all carefully mixed together in equalproportions, and the manure thus made is allowed to stand tillrequired for use. Ten days before the time fixed for sowing, narrowtrenches, about one inch in depth, are dug in the furrows, between therows of standing wheat or barleys and the manure is liberallysprinkled along them by hand. For one night before sowing the seed issteeped in water. It is then taken out, slightly mixed with strawashes, and sown in the trenches at intervals of a few inches. Whensown, it is covered with earth to the depth of half an inch, andgently trampled down by foot. Four or five days after sowing, the budsbegin to appear above the earth, and almost simultaneously the wheator barley between which they grow is ripe for the sickle. While thelatter is being harvested, the cotton may be left to itself, but notfor very long. The buds appear in much larger numbers than the soilcould support if they were allowed to grow. They have accordingly tobe carefully thinned out, so that not more than five or six plants areleft in each foot of length. The next process is the sprinkling of amanure composed of one part night soil and three parts water, andagain, subsequent to this, there are two further manurings; one of amixture of dried sardines, lees of oil, and lees of rice beer, whichis applied about the middle of June, when the plant has attained aheight of four inches; and again early in July, when the plant hasgrown to a height of six or seven inches, a further manuring of nightsoil, mixed with a larger proportion of water than before. At thisstage the head of the plant is pinched off with the fingers, in orderto check the excessive growth of the stem, and direct the strengthinto the branches, which usually number five or six. From thesebranches minor ones spring, but the latter are carefully pruned off asthey appear. In the middle of August the flowers begin to appeargradually. They fall soon after their appearance, leaving in theirplace the pod or peach (_momo_), which, after ripening, opens inOctober by three or four valves and exposes the cotton to view. Thecotton is gathered in baskets, in which it is allowed to remain till abright, sunshiny day, when it is spread out on mats to dry and swellin the sun for two or three days. After drying, the cotton is packedin bags made of straw matting, and either sold or put aside until suchtime as the farmer's leisure from other agricultural operationsenables him to deal with it. The average yield of cotton in gooddistricts in Japan is about 120 lb. To the acre, but as cotton is onlya secondary crop, this does not therefore represent the whole profitgained by the farmer from his land. The prefectures in which theproduction is largest are Aichi on the east coast, Osaka, Hiogo, Hiroshima, and Yamaguchi on the inland sea, and Fukui and Ishikawa onthe west coast. Vice-consul Longford says that the manufacture ofcotton 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 onwhose land the cotton is grown, and not only what is required for thewants of his own family is spun and woven by the female membersthereof, but a surplus is also produced for sale. 

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

The first operation in the manufacture is that of ginning, which isconducted by means of a small implement called the _rokuro_, orwindlass. This consists of two wooden rollers revolving in oppositedirections, fixed on a frame about 12 inches high and 6 inches inwidth, standing on a small platform, the dimensions of which slightlyexceed that of the frame. The operator, usually a woman, kneels on oneside of the frame, holding it firm by her weight, works the rollerwith one hand, and with the other presses the cotton, which she takesfrom a heap at her side, between the rollers. The cotton passesthrough, falling in small lumps on the other side of the frame, whilethe seeds fall on that nearest the woman. The utmost weight ofunginned cotton that one woman working an entire day of ten hours cangive is from 8 lb. To 10 lb. , which gives, in the end, only a littleover 3 lb. Weight of ginned cotton, and her daily earnings amount toless than 2d. A few saw gins have been introduced into Japan duringthe last fifteen years, but no effort has been made to secure theirdistribution throughout the country districts. After ginning, acertain proportion of the seed is reserved for the agriculturalrequirements of the following year, and the remainder is sent to oilfactories, where it is pressed, and yields about one-eighth of itscapacity in measurement in oil, the refuse, after pressing, being usedfor manure. The ginning having been finished in the country districts, the cotton is either packed in bales and sent to the dealers in thecities, or else the next process, that of carding, is at onceproceeded with on the spot. 

This process is almost as primitive as that of the ginning. A longbamboo, sufficiently thin to be flexible, is fastened at its base to apillar or the corner of a small room. It slopes upward into the centerof the room, and from its upper end a hempen cord is suspended. Tothis is fastened the "bow, " an instrument made of oak, about five feetin length, two inches in circumference, and shaped like a ladle. Astring of coarse catgut is tightly stretched from end to end of thebow, and this is beaten with a small mallet made of willow, bound atthe end with a ring of iron or brass. The raw cotton, in its coarsestate, 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 andfalls it catches the rough cotton, cuts it to the required degree offineness, removes impurities from it, and flings it to the side of theoperator, where it falls on a hempen net stretched over a four-corneredwooden frame. The spaces of the net are about one-quarter of an inchsquare, and through these any particles of dust that may still haveadhered to the cotton fall to the floor, leaving piled on top of thenet the pure cotton wool in its finished state. This work is alwaysperformed by a man, and by assiduous toil throughout a long day, oneman can card from ten to twenty pounds weight of raw cotton. Payment ismade in proportion to the work done, and in the less remote countrydistricts is at the rate of about one penny for each pound carded. Asregards spinning and weaving, in the first of these branches of cottonmanufacture the Japanese have largely had recourse to the aid offoreign machinery, but it is still to a much greater extent a domesticindustry, or at best carried on like weaving in the establishments ofcotton traders, in which a number of workers, varying from 20 to 100 ormore, each with his own spinning wheel, are collected together. ConsulLongford says the spinning wheel used in Japan differs in no respectfrom that used in the country 300 years ago or (except that bambooforms an integral part of the materials of which it is made) from thatused in England prior to the invention of the jenny. The cost of one ofthe wheels is about 9d. , it will last for five or six years, and withit a woman of ordinary skill can spin about 1 lb. Of yarn in a day often hours, earning thereby about 2d. There are at present in variousparts of Japan, in all, 21 spinning factories worked by foreignmachinery. Of four of these there is no information, but of theremainder, one has 120 spindles; eleven, 2, 000 spindles; two, 3, 000spindles; two, 4, 000 spindles; and one, 18, 000 spindles. --_Journal Soc. Of Arts. _

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

CENTRIFUGAL EXTRACTORS. 

By ROBERT F. GIBSON. 

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

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

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

There are two methods of discharging in continuous working--the sugaris thrown out periodically as the basket fills, or continuously. Inneither case is the speed slackened. In the first either the upperhalf of the basket has an upward motion, on the lower half a downwardmotion (Pat. 252, 483); and through the opening thus made the sugar isthrown. Fig. 22 (R. B. Palmer & Sons) is a machine of this kind. Thebottom, B, with the cone distributor, _a_, have downward motion. 

[Illustration: Fig. 22. ]

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

BASKET. --The construction of the basket is exceedingly important. Hardexperience has taught this. When centrifugals were first introduced, users were compelled by law to put them below ground; for theyfrequently exploded, owing to the speed being suddenly augmented byinequalities in the running of the engine or to the basket being tooweak to resist the centrifugal force of the overcharge. Increasing thethickness merely adds to the centrifugal force, and hence to thedanger, as even a perfectly balanced basket may sever. 

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

The basket wall has been variously constructed. In one case itconsists of wire wound round and round and fastened to uprights, commonly known as the "wire basket;" in another case of a peripherywithout perforations, but spirally corrugated and having an opening atthe bottom for the escape of the extracted liquid; in still another ofa series of narrow bars or rings, placed edgewise, packed as close asdesired. An advantage of this last style is that it is easily cleaned. 

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

As to comparative wear, it maybe remarked that one perforated basketwill 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 6feet in diameter--a size which can be run only at a comparatively slowspeed. 

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

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

DISCHARGING. --The drained sugar may either be lifted over the top ofthe basket (in machines which stop to be emptied), or be cast throughopenings in the bottom provided with valves. A section of the best formof valve may be seen in Figs. 15 and 17. Fig. 23 is a plan of theopenings. The valve turns on the basket bearing. It may be constructedto open in the same direction in which the basket turns; so that whenthe brake is put on, the inertia of the valve operates to open it andwhile running to keep it closed. There are many other styles, but noother need be mentioned. 

[Illustration: Fig. 23. ]

CASING. --The different styles of casing may be seen by reference to thevarious drawings. In one machine (not described) the casing is rigidlyfixed to the basket, space enough being left between the bottom of thebasket and the bottom of the casing to hold all the molasses from acharge. This arrangement merely adds to the bulk of the revolvingparts, and no real advantage is gained. 

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

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

CANE AND BEET MACHINES. --The first step in the process of sugar makingis the extraction of the juice from the beet or cane. This juice isobtained 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 tothe basket. The material is fed in and moves downward under increasedpressure, the sirup released flying out through the perforations of thebasket, the whole revolving at high velocity. The solid portion fallsout at the bottom. Another plan suggested (Pat. 343, 932) is to let aloose cover of an ordinary cylindrical basket screw itself down intothe basket, by reason of its slower velocity (owing to inertia), causing pressure on the charge. 

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

DRIERS. --Another important division of this first class of centrifugalsis that of driers or, as they are variously styled, whizzers, wringers, hydro-extractors. The charge in these is never large in weight comparedto a sugar charge, and its initial distribution can be made moresymmetrical. The uses of driers are various, such as extracting waterfrom clothes, cloth, silk, yarns, etc. Water may be introduced at thecenter of the basket from above or below to wash the material beforedraining. A typical form of drier is shown in Fig. 24. (Pat. Aug. 22, 1876--W. P. Uhlinger. ) Baskets have been made removable for use indyeing establishments, basket and load together going into dyeing vat. Yarn and similar material can be drained by a method analogous to thatof 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 layersaround the shaft in the basket, and the action is such during theoperation as to cause the yarn to stand out in radial lines. 

[Illustration: Fig. 24. ]

Driers are not materially different from sugar machines. Any of thedevices before enumerated for meeting vibrations in the latter may beapplied to the former. There is one curious invention which has beenapplied to driers only (Pat. 322, 762--W. H. Tolhurst). See Fig. 25. Aconvex shaft-supporting step resting on a concave supporting base, with the center of its arc of concavity at the center of the upperuniversal joint, has been employed, and its movements controlled bysprings, but the step was apt to be forced from its support. Thedrawing shows the improvement on this, which is to give theshaft-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 coursedemands fixed bearings. The engine is very small. One size used is 3"×4". When a higher velocity of basket is required, we have the arrangementin Fig. 26. 

[Illustration: Fig. 26. ]

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

[Illustration: Fig. 27. ]

One plan (Pat. 346, 030), designed to combine the advantages of a directacting motor and an oscillating shaft, mounts the whole machine, motorand all, on a rocking frame. The spindle is of course in fixed bearingsin 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 arefrequently injurious fumes. The belt will be alternately dry and wet, stretched and limp, and wears out rapidly and is liable to sever. Inall machines in which the shaft oscillates, if the center ofoscillation does not lie in the central plane of the belt, the tensionof the latter is not uniform. This affects badly both the belt and therunning. A reference to the various figures will show the best positionfor the pulley. 

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

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

Figs. 15 and 16 (I) give sectional views of a brake for hangingmachines. Figs. 19, 20, and 21 give two sections and a view of a brakewhich can be used on both hanging and standing machines. A very simpleform of brake is shown in Figs. 24, 26, and 27 (A), a mere blockpressing 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 yarnsand fabrics, and such other fibrous material or mixtures of materialsas are from their nature affected in color or quality when hydrocarbonsare used for the purpose of extracting such oily or fatty matters, andare subsequently removed from the material under treatment by the slowprocess of admitting steam, or using other means of raising thetemperature to the respective boiling points of such hydrocarbons, andso driving them off by evaporation. " In the centrifugal methodcarbon-bisulphide, or some other volatile agent, is admitted and isdriven through the material by centrifugal force, when the necessaryreactions take place, and is allowed to escape in the form ofhydrocarbons. A machine differing only in slight particulars from theabove is used for cleansing wool. 

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

OIL FROM METAL CHIPS. --Very material savings are made in many factoriesby collecting the metal chips and turnings, coated and mixed with oil, which fall from the various machines, and extracting the oilcentrifugally. The separator consists of a chip holder, having animperforate shell flaring upward and outward from the spindle (in fixedbearings) to which it is attached. When filled, a cover is placed uponit and keyed to the spindle. Between the cover and holder there is asmall annular opening through which oil, but not chips, can escape. Fig. 29 (Pat. 225, 949--C. F. Roper) is designed (like the greater partof the drawings inserted) to show relative position of parts merely, and not relative _size_. This style of machine can be used for sugarseparating (Pat. 345, 994--F. P. Sherman) and many other purposes, towhich, 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 sugarmachine. The flakes of paraffine, stearine, etc. , which are to beextracted, when chilled are very brittle and would be disintegratedupon being hurled against a plain wire gauze and would escape. Even awoven fabric presents too harsh a surface. It is necessary to have avery elastic basket lining of wool, cotton, or other fibrous material. The basket itself may be either wire or perforated, but must have aperfectly smooth bottom. 

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

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

Very fine sawdust is, to a considerable extent, employed in sugarrefineries as a filtering medium. By such use the sawdust becomes mixedwith sand, fine particles of cane, etc. As sawdust of such fineness isexpensive, it is desirable to purify it in order to reuse it. Acentrifugal (Pat. 353, 775--J. V. V. Booraem) built on the followingprinciple is used for this purpose. It has been observed that byrotating rather _slowly_ small particles of various substances inwater, the finer particles will be thrown outward and deposit near thecircumference of the vessel, while the heavier and coarser particleswill deposit nearer to or at the center, their centrifugal force notbeing sufficient to carry them out. A mere rod, extending radially inboth directions, serves by its rotation to set the water in motion. 

Another form of filter of this second kind (Pat. 148, 513) has arotating imperforate basket into which the impure liquor is run. Withinand concentric with it is another cylinder whose walls are of somefiltering medium. The liquid already partly purified by centrifugalforce passes through into the inner cylinder, thus becoming furtherpurified. Centrifugal filters are used also to cleanse gums forvarnishes. 

HONEY. --The simplest form of honey extractor (Pat. 61, 216) consists ofa square framework, symmetrical with respect to a vertical spindle. This framework is surrounded by a wire gauze. The combs, after havingthe heads of the cells cut off, are placed in comb-holders against thewire netting on the four sides, the cells pointing outward. The machineis turned by hand. The honey is hurled against the walls of a receivingcase and caught below. But few improvements have been made on this. Thelatest machines are still hand-driven, as a sufficiently high velocitycan be obtained in this manner. In one style the combs are placed upona floor which rests upon springs. The rotating box is given a slightvertical and horizontal reciprocatory motion, by which the combs aremade to grate on the wire gauze sides, breaking the cells andliberating the honey. Thus the labor of cutting the cells is saved. Every comb has two sides, and to present each side in succession to theoutside without removing from the basket, several devices have beenpatented. In some the comb holders are hinged in the corners of thebasket, and have an angular motion of ninety degrees. Decreasing thespeed is sufficient to swing these. The other side is then emptied byrevolving in the opposite direction. In one case each holder has aspindle of its own, connected with the main spindle by gearing and, topresent opposite side, turns through 180°. The usual number of sidesand hence of comb holders is four, but eight have been used. There areminor differences in details of construction, looking to the mostconvenient removal and insertion of comb, the reception of theextracted honey in cups, buckets, etc. , and the best method of givingrapid rotation, which cannot be touched upon. The product of theoperation is white and opaque, but upon heating regains its goldencolor 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, asstarch is heavier than the gluten with which it is mixed, the formerwill be immediately compacted against the periphery of the basket, lodging first in the lower corner, the starch and gluten forming twodistinct strata. A tube with a cutting edge enters the compacted massso deeply as to peel off the gluten and part of the starch, which iscarried through the tube to another compartment of the basket, justabove, where the same operation is performed, and so on. There may beonly one compartment, the tube carrying the gluten directly out of themachine. These machines are continuous working, and hence some way mustbe 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 becomestoo small, overflow must be allowed. One plan is to have an overflowopening made in the bottom of the basket in such a way that as thestarch wall thickens, the opening recedes toward the center. The starchwall is either lifted out in cakes or put again in suspension byspraying water on it and conducting the mixture off. 

A centrifugal (Pat. 74, 021) to separate liquids from paints depends onbuilding a wall of paint on the sides of the basket and carrying theliquids 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 hasbeen boiled with hops, albuminous matters are precipitated by thetannic acid, which must be extracted. Besides these the mixturefrequently contains husk, fiber, and gluten. The machine (Pat. 315, 876), although quite unique in construction, has the same principleof working as a sugar centrifugal, and need not be described. There isone point, however, which might be noticed--that air is introduced atabout the same point as the material, and has an oxidizing andrefrigerating effect. 

Class I. Includes also centrifugals for the following purposes: Theremoval of must from the grape after crushing, making butter, extracting oils from solid fats, separating the liquid and solid partsof sewerage, drying hides, skins, spent tan and the like, drying coilsof wire. 

HORIZONTAL CENTRIFUGALS. --Only vertical machines have been and will bedealt with. Horizontal centrifugals, that is, those whose spindles arehorizontal have been made, but the great inconvenience of charging anddischarging connected with them has occasioned their disuse; though inother respects for liquids they are quite as good as verticalseparators. Their underlying theory is practically the same as thathereinbefore discussed. 

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

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

The crudest form of creamer contains a number of bottles, with theirnecks all directed toward the spindle, filled with milk. The necks, inwhich the cream collects, are graduated to tell when the operation iscomplete. 

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 thebottom of the basket; or the spindle may be hollow and the milk suckedup through it from a basin below. It is usual to let the milk enterunder hydrostatic pressure (Pat. 239, 900--D. M. Weston) and let theforce of expulsion of the cream be dependent on this pressure. Thisrenders the escape quiet, and prevents churning. Gravity, too, is madeeffective in carrying the constituents off. 

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

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

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

The separated fluids may be received into recessed rings, havingdischarge pipes, the proportionate quantity discharged being regulatedby the proximity of the discharge lips to the surface of the ring, andthe centrifugal force being availed of to project the liquids throughthe discharge pipes. 

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

[Illustration: Fig. 30]

Fig. 30 (Pat. 355, 048--C. A. Backstrom) illustrates one of the latestand best styles of creamers. The milk enters at C. The skim milk passesinto tube, T, and the cream goes to the center and passes out of theopenings 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 theradial branch tubes, T^{1}, T^{2}, T^{3}, and T^{4}, some cream leavesit and goes to the center, while it passes down out of slit, t^{3}, andthence out of D^{6}. 

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

[Illustration: Fig. 31]

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

The principle exhibited in a separator of grains and seeds is veryneat. (Pat. 167, 297. ) See Fig. 32. That part of the machine with whichwe have to do consists essentially of a horizontal revolving disk. Themixed grains are cast on this disk, pass to the edge, and are hurledoff at a tangent. Suppose at A. Each particle is immediately acted onby three forces. For all particles of the same size and having the samevelocity the resistance of the air may be taken the same, that is, proportional to the area presented. The acceleration of gravity is thesame; but the inertia of the heavier grain is greater. The resultant ofthe two conspiring forces R and (M_v_^{2})/2 varies, and is greater fora 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 helicalblades or paddles, partaking of rapid rotary motion within a stationarycylinder of wire netting. The dust, constituting the valuable part ofthe product, is hurled out as fast as formed. In this style of machine, beaters are necessary not only for pulverizing, but to get up rotarymotion for generating centrifugal force. In the classes preceding, thefriction of the basket sufficed for this latter purpose; but here thereis no rotating basket and no definite charge. As the material fallsthrough the machine, separation takes place. Various kinds of ore maybe treated in the same manner. 

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

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

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

CLASS IV. , GASES AND SOLIDS. --There is a very simple contrivanceillustrating machines of this class used to free air from dust or otherheavy solid impurities which may be in suspension. See Fig. 33. The airenters the passage, B (if it has no considerable velocity of itself, itmust be forced in), forms a whirlpool in the conically shapedreceptable, A, and passes up out of the passage, D. The heavy particlesare 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 othermetal castings, if not separated, render the castings more or lessporous. This separation is effected by subjecting the molten metal tothe action of centrifugal force under exclusion of air, producing notonly the most minute division of the particles, but also a vacuum, bothfavorable conditions for obtaining a dense metal casting. 

Most of the devices for drying steam come under this head. Such arethose in which the steam with the water in suspension is forced to takea circular path, by which the water is hurled by centrifugal forceagainst the concave side of the passage and passes back to the water inthe boiler. 

SPEED. --The centrifugal force of a revolving particle varies, as wehave seen, as the square of the angular velocity, so that the efforthas been to obtain as high a number of revolutions per minute as wasconsistent with safety and with the principle of the machine. Forexample, creamers which are small and light make 4, 000 revolutions perminute, though the latest styles run much more slowly. Driers and sugarmachines vary from 600 to 2, 000, while on the other hand the necessityof keeping the mercury from hurling off in an amalgamator prevents itsturning more rapidly than sixty or eighty times a minute. 

However, speed in another sense, the speed with which the operation isperformed, is what especially characterizes centrifugal extractors. Inthis particular a contrast between the old methods and the new isimpressive. Under the action of gravity, cream rises to the milk'ssurface, but compare the hours necessary for this to the almostinstantaneous separation in a centrifugal creamer. The sugarmanufacturer trusted to gravity to drain the sirup from his crystals, but the operation was long and at best imperfect. An average sugarcentrifugal will separate 600 pounds of magma perfectly in threeminutes. Gold quartz which formerly could not pay for its mining is nowmaking its owners' fortunes. It is boasted by a Southern company thatwhereas they were by old methods making twenty-five _cents_ per ton ofgold quartz, they now by the use of the latest amalgamator maketwenty-five _dollars_. Centrifugal force, as applied in extractors, hasopened up new industries and enlarged old ones, has lowered prices andadded to our comforts, and centrifugal extractors may well command, asthey do, the admiration of all as wonderful examples of the way inwhich this busy age economizes time. 

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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 carrecently adopted by the Bone-Guelma Railroad Company, and which hasisolated compartments opening upon a lateral passageway. In thisarrangement, which is due to Mr. Desgranges, the lateral passagewaydoes not extend all along one side of the car, but passes through thecenter of the latter and then runs along the opposite side so as toform a letter S. The car consists in reality of two boxes connectedbeneath the transverse passageway, but having a continuous roof andflooring. The two ends are provided with platforms that are reached bymeans of steps, and that permit one to enter the corresponding half ofthe car or to pass on to the next. The length from end to end is 33feet in the mixed cars, comprising two first-class and foursecond-class compartments, and 32 feet in cars of the third class, with six compartments. The width of the compartments is 5. 6 and 5feet, according to the class. The passageway is 28 inches in width inthe mixed cars, and 24 in those of the third class. The roof is soarranged as to afford a circulation of cool air in the interior. 

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

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

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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 tostreet traffic. The superstructure is in two distinct portions, separated by a point of high ground. The main portion, extendingacross the river valley from Hill street to Jennings avenue, is 2, 840feet long on the floor line, including the river bridge, a swing 233feet in length; the other portion, crossing Walworth run from Davidsonstreet to Abbey street, is 1, 093 feet long. Add to these the earthworkand masonry approaches, 1, 415 feet long, and we have a total length of5, 348 feet. The width of roadway is 40 feet, sidewalks 8 feet each. The elevation of the roadway above the water level at the rivercrossing is 102 feet. The superstructure is of wrought iron, mainlytrapezoidal trusses, varying in length from 45 feet to 150 feet. Theriver piers are of first-class masonry, on pile and timber foundations. The other supports of the viaduct are wrought iron trestles on masonrypiers, resting on broad concrete foundations. The pressure on thematerial beneath the concrete, which is plastic blue clay of varyingdegrees of stiffness mixed with fine sand, is about one ton per squarefoot. 

The Cuyahoga valley, which the viaduct crosses from bluff to bluff, iscomposed mainly of blue clay to a depth of over 150 feet below theriver 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 diameterat small end are driven for the bridge piers either side of the riverbed, and these are cut off with a circular saw 18 feet below thesurface of the water. Excavation by dredging was made to a depth of 3feet below where the piles are cut off to allow for the rising of theclay during the driving of the piles. The piles are spaced about 2feet 5 inches each way, center to center. The grillage or platformcovering the piles consists of 14 courses of white oak timber, 12inches by 12 inches, having a few pine timbers interspersed so as toallow the mass to float during construction. The lower half of theplatform was built on shore, care being taken to keep the lowersurface of the mass of timber out of wind. The upper and lowersurfaces of each timber were dressed in a Daniels planer, and allpieces in the same course were brought to a uniform thickness. Thetimbers in adjacent courses are at right angles to each other. Thelower course is about 58 feet by 22 feet, the top course about 50 by24 feet, thus allowing four steps of one foot each all around. Thefirst course of masonry is 48 feet by 21 feet 8 inches; the firstcourse of battered work is 41 feet 8½ inches by 16 feet 3 inches. Thusthe area of the platform on the piles is 1, 856 square feet, and of thefirst batter course of masonry 777. 6 square feet, or in the ratio of2. 4 to 1. The height of the masonry is 78 feet above the timber, or73½ feet above the water. The number of piles in each foundation is312. The average load per pile is about 11 tons, and the estimatedpressure per square inch of the timber on the heads of the piles isabout 200 pounds. 

To prevent the submersion of the lower courses of masonry duringconstruction, temporary sides of timber were drift-bolted to themargin of the upper course of the timber platform, and carried highenough to be above the surface of the water when the platform was sunkto the head of the piles by the increasing weight of masonry. 

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

The risks and delays by this method of constructing the foundationswere much less, and the cost also, than if an ordinary coffer dam hadbeen used. Also the total weight of the piers is much less, as thatportion below a point about two feet below the water adds nothing totheir weight. 

The piles were driven with a Cram steam hammer weighing two tons, in aframe weighing also two tons. The iron frame rests directly upon thehead of the pile and goes down with it. The fall of the hammer isabout 40 inches before striking the pile. The total penetration of thepiles into the clay averaged 27 feet. The settlement of the pileduring the final strokes of the hammer varied from one quarter tothree 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 uponconcrete beds, except a few near the river on the north side, wherepiles are required. 

The four abutments with their retaining walls are of first-classrock-faced masonry. The footing courses are stepped out liberally, soas to present an unusually large bottom surface. They rest on beds ofconcrete 4 feet thick. The foundation pits are about 50 feet below thetop of the bluffs, and are in a material common to the Clevelandplateau, a mixture of blue sand and clay, with some water. Theestimated load of masonry on the earth at the bottom of the concreteis one and seven tenths tons to the square foot. Two of the largeabutments were completed last season. They show an average settlementof three eighths of an inch since the lower footing courses were laid. 

The facts and figures here given regarding the viaduct were kindlyfurnished by the city civil engineer, C. G. Force, who has the work incharge. --_Jour. Asso. Of Eng. Societies. _

 * * * * *

For sticking paper to zinc, use starch paste with which a littleVenice turpentine has been incorporated, or else use a dilute solutionof 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 governmenton pumping machinery, to remove the water from a dry dock for vesselsof 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 feetdeep, with a capacity at mean tide of 9, 000, 000 gallons. 

After receiving the contract, several different sizes of pumps wereconsidered, but the following dimensions were finally chosen: Two 42inch centrifugal pumps, with runner 66 inches in diameter anddischarge pipes 42 inches, each driven direct by a vertical enginewith 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 destinationin the short space of two weeks, and the pumps were there erected onfoundations prepared by the government. 

From the "Report of the Chief of Bureau of Yards and Docks" I quotethe 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 anabsolute certainty that in every chemical action there is a productionof electricity in a more or less notable quantity, according to thenature 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 accompaniedwith an appreciable manifestation of electricity? If we consult theannals of science and works treating on electricity in regard to thissubject, we find very few examples and experiments proper to elucidatethe question. 

Mr. Mascart is content to say: "Some experiments seem to indicate thatthe solidification of a body produces electricity. " Mr. Becquerel doesmore than doubt--he denies: "As regards the disengagement ofelectricity in the changing of the state of bodies, we find none. "This assertion is too sweeping, for further along we shall cite factsthat prove, on the contrary, that in the phenomena of crystallization(to speak of this change of state only) there is an unequivocalproduction of electricity. Let us remark, in the first place, thatwhen a number of phenomena of physical and chemical orderincontestably testify to the very intimate correlation that existsbetween the molecular motions of bodies and their electrical state, itwould not be very logical to grant that electricity is absent incrystallization. 

Thus, to select an example from among physical effects, the vibratoryphenomena that occur in telephone transmissions, under the influenceof a very feeble electric current, show us that the molecularconstitution of a solid body is extremely variable, although withinslight limits. The feeblest modification in the electric current maybe shown by molecular motions capable of propagating themselves toconsiderable distances in the conducting wire. Conversely, it islogical to suppose that a modification in the molecular state of abody must bring electricity into play. If, in the phenomena ofsolidification, and particularly of crystallization, we collect butsmall quantities of electricity, that may be due to the fact that, under the experimental conditions involved, the electricity is more orless completely absorbed by the work of crystal building. 

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

There is no doubt that electricity exists immovable or in circulationeverywhere, 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 placebefore our eyes. A body cannot change state, nature, temperature, form, or place, even, without electricity being brought into play, andwithout its accompanying such modifications, if it presides therein. Like heat, it is _the_ natural agent _par excellence_; it is theinvisible and ever present force which, in the ultimate particles ofmatter, causes those motions, vibrations, and rotations that have theeffect of changing the properties of bodies. Upon entering theirintimate structure, it orients or groups their atoms, and separatestheir molecules or brings them together. From this, would it not besurprising if it did not intervene in the wonderful phenomenon ofcrystallization? 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, thatphysicists have endeavored to reduce to one single principle all thecauses that are now distinct. The mechanical theory of heat has made agreat stride in this direction. 

The equivalence of the thermic, mechanical and chemical forces hasbeen demonstrated; the only question hereafter will be to select fromamong such forces the one that must be adopted as the sole principle, in order to account for all the phenomena that depend upon thesecauses of various orders. But in the present state of science, it isnot yet possible to explain completely by heat or electricity, takenisolatedly, all the effects dependent upon the causes just mentioned. We must confine ourselves for the present to a study of the relationsthat exist between the principal natural forces--affinity, molecularforces, heat, electricity, and light. But from the mutual dependenceof such forces, it is admitted that, in every natural phenomenon, there is a more or less apparent simultaneous concurrence of thesecauses. 

In order to explain electric or magnetic phenomena, and also those ofcrystallization, it is admitted that the atoms of which bodies arecomposed are surrounded, each of them, with a sort of atmosphereformed of electric currents, owing to which these atoms are attractedor repelled on certain sides, and produce those varied effects that weobserve 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 insolids, they are nevertheless capable of arranging themselves and ofbecoming polarized in a regular order, special to each kind of atom, in order to produce crystals of geometrical form characteristic ofeach species. Thus, as Mr. Saigey remarks in "Physique Moderne" (p. 181): "So long as the atmospheres of the molecules do not touch eachother, no trace of cohesion manifests itself; but as soon as they cometogether force is born. We understand why the temperatures of fusionand solidification are fixed for the same body. Such effects occur atthe precise moment at which these atmospheres, which are variable withthe temperature, have reached the desired diameter. "

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

Although the phenomenon of crystallization does not essentially dependupon temperature, but rather upon the relative quantity of liquid thatholds the substance in solution, it will be conceived that a momentwill arrive when, the liquid having evaporated, the atmospheres willbe close enough to each other to attract each other and becomepolarized and symmetrically juxtaposed, and, in a word, tocrystallize. 

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

Under such circumstances, it may take on regular, geometrical formscalled crystalline. Such conditions are brought about by differentprocesses--fusion, volatilization, solution, the dry way, wet way, andelectric way. Further along, we shall give some examples of the lastnamed means. 

Let us add that crystallization may be regarded as a general propertyof bodies, for the majority of substances are capable ofcrystallizing. Although certain bodies seem to be amorphous at firstsight, it is only necessary to examine their fracture with a lens ormicroscope to see that they are formed of a large number of smalljuxtaposed crystals. Many amorphous precipitates become crystalline inthe long run. 

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

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

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

The use of voltaic apparatus of high tension has allowed Mr. Cross toform a large number of mineral substances artificially, and amongthese we may mention carbonate of lime, arragonite, quartz, arseniateof copper, crystalline sulphur, etc. 

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

There is no doubt as to the part played by electricity in the chemicaleffects of electro-metallurgy, but it will not prove useless for oursubject to remark that when, in this operation, the current has becometoo weak, the deposit of metal, instead of forming in a thin, adherent, and uniform layer, sometimes occurs under the form ofprotuberances and crystalline, brittle nodules. When, on the contrary, the current is very strong, the deposit is pulverulent, that is, in aconfused 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 ofgalvanic deposits. 

When, into a solution of acetate of lead, we pass a current throughtwo platinum electrodes, we observe the formation, at the negativepole, of numerous arborizations of metallic lead that grow under theobserver's eye (Fig. 1). The phenomenon is of a most interestingcharacter when, by means of solar or electric light, we project thesebrilliant vegetations on a screen. One might believe that he waswitness of the rapid growth of a plant (Fig. 2). The same phenomenonoccurs none the less brilliantly with a solution of nitrate of silver. A large number of saline solutions are adapted to thesedecompositions, in which the metal is laid bare under a crystallineform. Further along we shall see another means of producing analogousramifications, 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 veryslow secular variations, and can be determined with a precision and anease which compel its employment. Still it is true that the second isan arbitrary and a variable unit--arbitrary, in as far as it has norelation with the properties of matter, with physical constants;variable, since the duration of the diurnal movement undergoes causesof secular perturbation, some of which, such as the friction of thetides, are not as yet calculable. 

We may ask if it is possible to define an absolutely invariable unitof 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 andindependently of any astronomical hypothesis. 

Now, the study of certain electrical phenomena furnishes a unit oftime which is absolutely invariable, as this magnitude is a specificconstant. Let us consider a conductive substance which may always befound identical with itself, and to fix our ideas let us choosemercury, taken at the temperature of 0° C. , which completely fulfillsthis condition. We may determine by several methods the specificelectric resistance, [rho], of mercury in absolute electrostaticunits; [rho] is a specific property of mercury, and is consequently amagnitude absolutely invariable. Moreover, [rho] is _an interval oftime_. We might, therefore, take [rho] as a unit of time, unless weprefer to consider this value as an imperishable standard of time. 

In fact, [rho] is not simply a quantity the measure of which is foundto be in relation with the measure of time. It is a concrete intervalof time, disregarding every convention established with reference tomeasures and every selection of unit. It may at first sight, appearsingular that an interval of time is found in a manner hidden underthe designation _electric resistance_. But we need merely call to mindthat in the electrostatic system the intensities of the current arespeeds of efflux and that the resistances are times, i. E. , the timesnecessary for the efflux of the electricity under given conditions. Wemust, in particular, remember what is meant by the specificresistance, [rho] of mercury in the electrostatic system. If weconsider a circuit having a resistance equal to that of a cube ofmercury, the side of which = the unit of length, the circuit beingsubmitted to an electromotive force equal to unity, this circuit willtake a given time to be traversed by the unit quantity of electricity, and this time is precisely [rho]. It must be remarked that theselection of the unit of length, like that of the unit of mass, isindifferent, for the different units brought here into play depend onit in such a manner that [rho] is not affected. 

It is now required to bring this definition experimentally intoaction, i. E. , to realize an interval of time which may be a knownmultiple of [rho]. This problem may be solved in various ways, [1] andespecially 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 sametime the two antagonistic circuits of a differential galvanometer. Inthe first circuit, which has a resistance, R, the battery sends acontinuous current of the intensity, I; in the second circuit thebattery sends a discontinuous series of discharges, obtained bycharging periodically by means of the battery a condenser of thecapacity, C, which is then discharged through this second circuit. Theneedle of the galvanometer remains in equilibrium if the two currentsyield equal quantities of electricity during one and the same time, [tau]. 

Let us suppose this condition of equilibrium realized and the needleremaining motionless at zero; it is easy to write the conditions ofequilibrium. During the time, [tau], the continuous current yields a Equantity of electricity = -- [tau]; on the other hand, each charge of Rthe 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 anarbitrary 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 tC 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 unitsundetermined. 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; wehave simply [Theta] = _pq_. 

If we suppose that the commutator which produces the successivecharges and discharges of the condenser consists of a vibrating tuningfork, we see that the duration of a vibration is equal to the productof the two abstract numbers, _pq_. 

It remains for us to ascertain to what degree of approximation we candetermine _p_ and _q_. To find _q_ we must first construct a column ofmercury of known dimensions; this problem was solved by theInternational Bureau of Weights and Measures for the construction ofthe legal ohm. The legal ohm is supposed to have a resistance equal to106. 00 times that of a cube of mercury of 0. 01 meter, sidemeasurement. The approximation obtained is comprised between 1/50000and 1/200000. To obtain _p_, we must be able to construct a planecondenser of known capacity. The difficulty here consists in knowingwith 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 bytransparence Fizeau's interference rings. Fizeau's method will thenpermit us to arrive at a close approximation. In fine, then, we may, _a priori_, hope to reach an approximation of one hundred-thousandthof the value of _pq_. 

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

As an indicator of variations this apparatus can be of remarkablesensitiveness, which may be increased indefinitely by enlarging itsdimensions. 

With a battery of 10 volts, a condenser of a microfarad, 10 dischargesper second, and a Thomson's differential galvanometer sensitive to10^{-10} amperes, we obtain already a sensitiveness of 1/1000000, i. E. , a variation of 1/1000000 in the speed is shown after someseconds of a deviation of one millimeter. Even the stroboscopic methoddoes not admit of such sensitiveness. 

We may therefore find, with a very close approximation, a speed alwaysthe same on condition that the solid parts of the apparatus (thecondenser and the resistance) are protected from causes of variationand used always at the same temperature. Doubtless, a well-constructedastronomical clock maintains a very uniform movement; but the electricclock is placed in better conditions for invariability, for all theparts are massive and immovable; they are merely required to remainunchanged, and there is no question of the wear and tear ofwheel-work, the oxidation of oils, or the variations of weight. Inother words, the system formed by a condenser and a resistanceconstitutes 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 apendulum by means of electricity, which differs from previous devicesof the same character in that the impulse given to the pendulum ateach vibration is independent of the strength of the current employed, and that the pendulum itself is entirely free, save at the point ofsuspension. The vibrations are maintained, not by direct impulsion, but by a slight horizontal displacement of the point of suspension inalternate directions. 

This, as M. Carpentier observes, is the method which we naturallyadopt in order to maintain the amplitude of swing of a heavy bodysuspended from a cord held in the hand. The required movement of thepoint of suspension is effected by means of a polarized relay, throughthe coils of which the current is periodically reversed by the actionof the pendulum, in a manner which will presently be explained. Thearmature of the relay oscillates between two stops whose distanceapart is capable of fine adjustment. 

It is clear, therefore, that the impulse is independent of thestrength of the current in the relay, provided that the armature isbrought up to the stop on either side. The reversal of the current iseffected by means of a small magnet carried by the bob of thependulum, and which as it passes underneath the point of suspension isbrought close to a soft iron armature, which has the form of an arc ofa circle described about the point of suspension. This armature ispivoted at its center, and thus executes vibrations synchronously withthose of the pendulum. These vibrations are adjusted to a very narrowrange, but are sufficient to close the contacts of a commutator whichreverses 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 beenhonored by scientists of England and the Continent, has lately becomefamilar to everyone, even in unprofessional circles, in Germanybecause of his operations on the Crown Prince's throat. If his wideexperience and great skill enable him to permanently remove the growthfrom the throat of his royal patient, if his diagnosis and prognosisare confirmed, so that no fear need be entertained for the life andhealth of the Crown Prince, the English specialist will certainlydeserve the most sincere thanks of the German nation. Every phase ofthis treatment, every new development, is watched with suspense andhope. 

Many have been unable to suppress the expression of regret that thisimportant case was not under the care of a German, and part of thepress look upon it as unjust treatment of the German specialists. Butscience is international, it knows no political boundaries, and thechoice of Dr. Mackenzie by the family of the Crown Prince, whosesympathy with England is natural, cannot be considered a slight toGerman physicians when it is taken into consideration that the Germanauthorities pronounced the growth suspicious and advised a difficultand doubtful operation, and that Prof. V. Bergman recommended that aforeign authority be consulted. As Dr. Mackenzie removed theobstruction, which had already become threatening and, in fact, dangerous, causing a loss of voice, and promised to remove any newgrowth from the inside without danger to the patient, the Crown Princenaturally trusted him. Since Virchow has made a microscopic examinationof the part which was cut away, and has declared the new growth to bebenign, all Germans should watch the results of Dr. Mackenzie'soperations with sympathy, trusting that all further growth will beprevented, and that the Crown Prince will be restored to the Germanpeople in his former state of health. 

[Illustration: DR. MORELL MACKENZIE. ]

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

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

Since he founded the first English hospital for diseases of the throatand chest, in London in 1863, and held the position of lecturer ondiseases of the throat in the London Medical College, his career hasbeen watched with interest by the public, and his practice in Englandis remarkable. Therefore it is no wonder that his lately publishedwork "On the Hygiene of the Vocal Organs" has reached its fourthedition already. This work is read not only by physicians, but also bysingers 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 GreatBritain if fortune favors him and he restores the future Emperor ofGermany to his former strength and vigor, without which we cannotimagine this knightly form. The certainty with which Dr. Mackenziespeaks of permanent cures which he has effected in similar cases, together with the clear and satisfactory report of the greatpathologist Virchow, lead us to look to the future withconfidence. --_Illustrirte Zeitung. _

 * * * * *

HYPNOTISM IN FRANCE. [1]

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

The voluntary production of those abnormal conditions of the nerveswhich to-day are denoted by the term "hypnotic researches" hasmanifested itself in all ages and among most of the nations that areknown to us. Within modern times these phenomena were first reduced toa system by Mesmer, and, on this account, for the future deserve theattention of the scientific world. The historical description of thisdepartment, if one intends to give a connected account of itsdevelopment, and not a series of isolated facts, must begin with anotice of Mesmer's personality, and we must not confound the morerecent development of our subject with its past history. 

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

The second division of this historical development is carried on byBraid, whose most important service was emphasizing the subjectivityof the phenomena. Without any connection with him, and yet byfollowing out almost exactly the same experiments, ProfessorHeidenhain reached his physiological explanations. A third division isbased upon the discovery of the hypnotic condition in animals, andconnects itself to the _experimentum mirabile_. In 1872 the firstwritings on this subject appear from the pen of the physiologistCzermak; and since then the investigations have been continued, particularly by Professor Preyer. 

While England and Germany were led quite independently to the study ofthe same phenomena, France experienced a strange development, whichshows, as nothing else could, how truth everywhere comes to thesurface, and from small beginnings swells to a flood which carriesirresistibly all opposition with it. This fourth division of thehistory of hypnotism is the more important, because it forms thefoundation of a transcendental psychology, and will exert a greatinfluence upon our future culture; and it is this division to which wewish to turn our attention. We have intentionally limited ourselves toa chronological arrangement, since a systematic account wouldnecessarily fall into the study of single phenomena, and would farexceed the space offered to us. 

James Braid's writings, although they were discussed in detail inLittré and Robin's "Lexicon, " were not at all the cause of Dr. Philips' first books, who therefore came more independently to thestudy of the same phenomena. Braid's theories became known to himlater by the observations made upon them in Béraud's "Elements ofPhysiology" and in Littré's notes in the translation of Müller's"Handbook of Physiology;" and he then wrote a second brochure, inwhich he gave in his allegiance to braidism. His principal effort wasdirected to withdrawing the veil of mystery from the occurrences, andby a natural explanation relegating them to the realm of the known. The trance caused by regarding fixedly a gleaming point produces inthe brain, in his opinion, an accumulation of a peculiar nervouspower, which he calls "electrodynamism. " If this is directed in askillful manner by the operator upon certain points, it manifestsitself in certain situations and actions that we call hypnotic. Beyondthis somewhat questionable theory, both books contained a detaileddescription of some of the most important phenomena; but with thepractical meaning of the phenomena, and especially with theirtherapeutic value, the author concerned himself but slightly. Just onaccount of this pathological side, however, a certain attention hasbeen 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 operationpainless. "This long and horrible work, " says a journal of the day, "was much more like a demonstration in a dissecting room than anoperation performed upon a living being. " Although this operationproduced such an excitement, yet it was twelve years later beforedecisive and positive official intelligence was given of these factsby Broca, Follin, Velpeau, and Guérinau. But these accounts, as wellas the excellent little book by Dr. Azam, shared the fate of theirpredecessors. They were looked upon by students with distrust, and bythe disciples of Mesmer with scornful contempt. 

The work of Demarquay and Giraud Teulon showed considerable advance inthis direction. The authors, indeed, fell back upon the theory ofJames Braid, which they called stillborn, and of which they said, "_Elle est restée accrochée en route_;" but they did not satisfythemselves with a simple statement of facts, as did Gigot Suard in hiswork that appeared about the same time. Through systematic experimentsthey tried to find out where the line of hypnotic phenomena intersectedthe line of the realm of the known. They justly recognized thathypnotism and hysteria have many points of likeness, and in this waywere the precursors of the present Parisian school. They say that frommagnetic sleep to the hypnotic condition an iron chain can be easilyformed from the very same organic elements that we find in historicalconditions. 

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

Unbounded enthusiasm and unjust blame alike subsided into a silencethat was not broken for ten years. Then Charles Richet, a renownedscientist, came forward in 1875, impelled by the duty he felt he owedas a priest of truth, and made some announcements concerning thephenomena of somnambulism; and in countless books, all of which areworthy of attention, he has since then considered the problem from itsvarious sides. 

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

Jean Martin Charcot, the renowned neurologist of the ParisianSalpetriere, without exactly desiring it, was led into the study ofartificial somnambulism by his careful experiments in reference tohysteria, and especially by the question of _metallotherapie_, and inthe year 1879 had prepared suitable demonstrations, which were givenin public lectures at the Salpetriere. In the following years hedevoted himself to closer investigation of this subject, and washappily and skillfully assisted by Dr. Paul Richer, with whom wereassociated many other physicians, such as Bourneville, Regnard, Fere, and Binet. The investigations of these men present the peculiaritythat they observe hypnotism from its clinical and nosographical side, which side had until now been entirely neglected, and that theyobserve patients of the strongest hysterical temperaments. "If we canreasonably assert that the hypnotic phenomena which depend upon thedisturbance of a regular function of the organism demand for theirdevelopment a peculiar temperament, then we shall find the most markedphenomena when we turn to an hysterical person. "

The inferences of the Parisian school up to this time are somewhat thefollowing, but their results, belonging almost entirely to the medicalside of the question, can have no place in this discussion. Theydivide the phenomena of hystero-hypnotism, which they also call_grande hysterie_, into three plainly separable classes, which Charcotdesignates catalepsy, lethargy, and somnambulism. 

Catalepsy is produced by a sudden sharp noise, or by the sight of abrightly gleaming object. It also produces itself in a person who isin a state of lethargy, and whose eyes are opened. The most strikingcharacteristic of the cataleptic condition is immobility. The subjectretains every position in which he is placed, even if it is anunnatural one, and is only aroused by the action of suggestion fromthe rigor of a statue to the half life of an automaton. The face isexpressionless and the eyes wide open. If they are closed, the patientfalls into a lethargy. 

In this second condition, behind the tightly closed lids, the pupilsof the eyes are convulsively turned upward. The body is almostentirely without sensation or power of thought. Especiallycharacteristic of lethargy is the hyper-excitability of the nerves andmuscles (_hyperexcitabilite neuromusculaire_), which manifests itselfat the slightest touch of any object. For instance, if the extensormuscles 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 nervetrunk 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 fromlethargy by means of a slight pressure upon the _vertex_, and isparticularly sensitive to every psychical influence. In some subjectsthe eyes are open, in others closed. Here, also, a slight irritationproduces a certain amount of rigor in the muscle that has beentouched, but it does not weaken the antagonistic muscle, as inlethargy, nor does it vanish under the influence of the sameexcitement that has produced it. In order to put an end to thesomnambulistic condition, one must press softly upon the pupil of theeye, upon which the subject becomes lethargic, and is easily roused bybreathing upon him. In this early stage, somnambulism appears veryinfrequently. 

Charcot's school also recognize the existence of compound conditions, the history of whose symptoms we must not follow here. These slightlysketched results, as well as a number of other facts, were onlyobtained in the course of several years; yet in 1882 the fundamentalinvestigations of this school were considered virtually concluded. Then Dumont-Pallier, the head of the Parisian Hospital Pitié, cameforward with a number of observations, drawn also exclusively from thestudy of hystero-hypnotism, and yet differing widely from thosereached by the physicians of the Salpetriere. In a long series ofcommunications, he has given his views, which have in their turn beenviolently attacked, especially by Magnin and Bérillon. I give only themost important points. 

According to these men, the hyper-excitability of the nerves andmuscles is present not only in the lethargic condition, but in allthree periods; and in order to prove this, we need only apply thesuitable remedy, which must be changed for each period and everysubject. Slight irritations of the skin prove this most powerfully. Adrop of warm water or a ray of sunshine produces contractions of amuscle 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 asCharcot's school. They also are very decided about the three periods, whose succession does not appear to them as fixed; but they discovereda new fundamental law which regulates the production as well as thecessation of the condition--_La cause qui fait, defait_; that is, thestimulus which produces one of the three periods needs only to berepeated in order to do away with that condition. From this thefollowing diagram of hypnotic conditions is evolved:

[Illustration]

And, furthermore, Dumont-Pallier should be considered as the founderof a series of experiments, for he was the first one to show in adecisive manner that the duality of the cerebral system was proved bythese 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 brainhemisphere may be suppressed without nullifying the intellectualactivity or consciousness. Both hemispheres may be started at the sametime in different degrees of activity; and also, when the grade is thesame, they may be independently the seat of psychical manifestationswhich are in their natures entirely different. In close connectionwith this and with the whole doctrine of hemi-hypnotism, which isfounded 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 hypnoticstate, "fascination, " which preceded the three others, and manifesteditself by a tendency to muscular contractions, as well as throughsensitiveness to hallucination and suggestion, but at the same timeleft to the subject a full consciousness of his surroundings andremembrance of what had taken place. Descourtis, in addition, perceived a similar condition in the transition from hypnotic sleep towaking, which he called _delire posthypnotique_, and, instead of usingthe 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 chiefpeculiarity is that it considers hypnotism a nervous malady, and onethat must be treated clinically and nosographically, was opposed in1880 in two directions--one source of opposition producing greatresults, while the other fell to the ground. The latter joined itselfto the theory of the mesmerists, and tried, by means of exactexperiments, to measure the fluid emanating from the human body--anundertaking 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, touphold the fluidic explanation. Despine also thought that by its helphe had been able to explain the phenomena; but it was Baréty who, inthe year 1881, first turned general attention in this direction. According to him, mankind possesses a nerve force which emanates fromhim in different kinds of streams. Those coming from the eyes andfingers produce insensibility to pain, while those generated by thebreath cause hypnotic conditions. This nerve force goes out into theether, and there obeys the laws that govern light, being broken intospectra, etc. 

Claude Perronnet has more lately advanced similar views, and hisgreatest work is now in press. Frederick W. H. Myers and Edmund Gurneysympathize with these views, and try to unite them with the mesmeristdoctrine of personal influence and their theory of telepathy. Thethird champion in England of hypnotism, Prof. Hack Tuke, on thecontrary, sympathizes entirely with the Parisian school, onlydiffering from them in that he has experimented with satisfactoryresults upon healthy subjects. In France this view has lately beenaccepted by Dr. Bottey, who recognizes the three hypnotic stages inhealthy persons, but has observed other phenomena in them, andvehemently opposes the conception of hypnotism as a malady. Hisexcellently written book is particularly commended to those who wishto experiment in the same manner as the French investigator, withoutusing hysterical subjects. 

The second counter current that opposed itself to the Frenchneuropathologists, and produced the most lasting impression, isexpressed by the magic word "suggestion. " A generation ago, Dr. Liebault, the patient investigator and skillful physician, hadendeavored to make a remedial use of suggestion in his clinic atNancy. Charles Richet and others have since referred to it, butProfessor Bernheim was the first one to demonstrate its fullsignificance in the realm of hypnotism. According to him, suggestion--that is, the influence of any idea, whether receivedthrough the senses or in a hypersensible manner (_suggestionmentale_)--is the key to all hypnotic phenomena. He has not been ablein a single case to verify the bodily phenomena of _grandehypnotisme_without finding suggestion the primary cause, and on this accountdenies the truth of the asserted physical causes. Bernheim says thatwhen the intense expectance of the subject has produced a compliantcondition, a peculiar capacity is developed to change the idea thathas been received into an action as well as a great acuteness ofacceptation, which together will produce all those phenomena that weshould call by the name of "pathological sleep, " since they are onlyseparable in a gradual way from the ordinary sleep and dreamconditions. Bernheim is particularly strenuous that psychology shouldappear in the foreground of hypnotism, and on this point has beenstrongly upheld by men like Professors Beaunis and Richet. 

The possibility of suggestion in waking conditions, and also a longtime after the sleep has passed off (_suggestions posthypnotiques ousuggestions a (longue) echeance_), as well as the remarkable capacityof subjects to change their personality (_changement de lapersonnalite objectivation des types_), have been made the subject ofcareful investigation. The voluntary production of bleeding andstigmata through spiritual influence has been asserted, particularlyby Messrs. Tocachon, Bourru, and Burot. The judicial significance ofsuggestion has been discussed by Professor Liegeois and Dr. Ladame. Professor Pitres in Bordeaux is one of the suggestionists, thoughdiffering 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 physicalphenomena, endeavoring to explain them in a different manner. Theseexplanations carry us into two realms, the first of which has beenlately opened, and at present seems to abound more in enigmas than insolutions. 

_Metallotherapie_, which was called into existence by Dr. Burg, andfurther extended by Dr. Gellé, contains a special point ofinterest--the so-called transference in the case of hysterically orhypnotically affected persons. Transference is caused byelectro-magnetism, which has this peculiarity--that in the case ofspecially sensitive persons it can transfer the bodily affection fromleft to right, and _vice versa_. The transference of paralysis, thecures attempted on this plan, and the so-called "psychicaltransference, " which contains special interest for graphologists, areat the present time still open questions, as well as the closelyconnected theory of human polarity; and the odic experiments of Dr. Chazarain are yet waiting for their confirmation. At present theproblem of the connection between magnetism and hypnotism is underinvestigation, and in such a manner that we may hope for a speedysolution. 

Still stranger than these reports are the accounts of the distantoperation of certain bodies; at least, they seem strange to thoseunacquainted with psychometry and the literature of the past centuryrelating to this subject. Two physicians in Rochefort, ProfessorsBourru and Burot, in treating a hystero-epileptic person, found thatgold, even when at a distance of fifteen centimeters, produced in hima feeling of unbearable heat. They continued these experiments withgreat care, and, after a number of trials, came to thisconclusion--that in some persons certain substances, even whencarefully separated from them by long distance, exercise exactly thesame physiological influence as if introduced into their organism. Inorder to explain these phenomena, they refer to the radiating force ofBaréty, an explanation neither satisfactory to themselves nor toothers. Lately the distinguished Parisian physician, Dr. Luys, hasconfirmed by his experiments the existence of these phenomena, but hethinks the explanation referable to hyper-sensitiveness of the"_regions emotives et intellectuelles de l'encephale_" yet even he hasnot reached the kernel of the difficulty. 

In close connection with action at a distance is the question ofdistant 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 theinvestigations he is making upon a purely experimental basis. In Italythey have limited themselves to the study of isolated cases ofhystero-hypnotism, except as the phenomena of magnetic fascinationinvestigated by Donato have given rise to further research; but allthe books I have seen upon this subject, as well as many by Frenchauthors, suffer from ignorance of the latest English discoveries. 

With this I think that I have given a slight outline of the history ofhypnotic investigation to the end of the year 1886. I shall attempt acriticism of this whole movement at some other time, as space is notafforded to me here; but I should like to make this statement now, that two of the characteristic indications of this period are of thegravest import--first the method ("Our work, " says Richet, "is that ofstrictly scientific _testing_, _observation_, and _arrangement_");and, secondly, the result. Hypnotism has been received into the realmof scientific investigation, and with this the foundation of a trueexperimental psychology has been laid. 

MAX DESSOIR. 

 * * * * *

THE DUODENUM: A SIPHON TRAP. 

By MAYO COLLIER, M. S. Lond. , F. R. C. S. Eng. ; SeniorAssistant Surgeon, North-West London Hospital; Assistant Demonstratorof 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 theresooner or later escape. Fetid gases--except those generated in thestomach and duodenum--never pass upward, not even during vomiting dueto hernia, obstruction, and other causes. Physiologists, it wouldappear, have never busied themselves to find an explanation for thisapparent breach of the laws of gravity. The intestinal canal is a tubewith various dilatations and constrictions, but at no spot except thepylorus does the constriction completely obliterate the lumen of thetube, and here only periodically. It is perfectly evident, then, that, unless some system of trap exists in the canal, gases are free totravel from below upward in obedience to the laws of gravity, andwould, as a matter of fact, sooner or later do so. From the straight, course and vertical position of the oesophagus, a very slightpressure of gas in the stomach easily overcomes the closure of itscardiac sphincter and allows of escape. When the stomach has digestedits contents and the pylorus is relaxed, gases generated in theduodenum can and do ascend into the stomach and so escape. Normally, no fetid gases are generated in the stomach or duodenum. If we followthe course of the intestines down, we find that the duodenum presentsa remarkable curve. 

Now, there are some points of great interest in connection with thisremarkable, almost circular, curve of the duodenum. In the firstplace, this curve is a constant feature in all mammalians. Mr. Trevessays it is one of the most constant features in the anatomy of theintestines in man, and, speaking of mammalians in general, that thecurve of the duodenum varies in shape, but is never absent, becomingmore complex in some of the higher primates, but seldom less distinctthan in man. In birds the duodenum always forms a long loop embracingthe pancreas. 

A second point of great interest is the absolute constancy andfixation of its terminal portion at the point of junction with thejejunum, more correctly termed second ascending or fourth portion. Mr. Treves says that this fourth portion is never less than an inch, andis practically constant. It extends along the side of the left crus ofthe diaphragm opposite the second lumbar vertebra, and is there firmlyfixed to the front of the aorta and crus of the diaphragm by a strongfibro-muscular band, slinging it up and absolutely retaining it inposition. This band has been termed the "musculus suspensoriusduodeni, " but is chiefly composed of white fibrous tissue, and is moreof the native of a ligament than a muscle. This ligament is alwayspresent, and its position is never altered. The curve of the duodenummay descend as far as the iliac fossa, but the terminal portion isalways maintained by this band in its normal position. 

Another point of great constancy is the position of the pancreas andits relation to the curve of the duodenum. The duodenum always curvesround the head of the pancreas and is, as it were, moulded on it andretained in position by it. In birds the duodenum always forms a longloop embracing the pancreas. Further, the ducts of the liver andpancreas always open into the center Of the duodenum, eitherseparately or by a common opening. 

[Illustration]

Now, the absolute constancy of the curve of the duodenum, the completefixation of its fourth portion, the position of the pancreas, and theplace of entry of the ducts of the pancreas and liver, are allcomponent parts of a siphon trap, whereby gases generated below theduodenum are prevented from passing upward. A reference to theaccompanying diagrams will make this quite clear. A is a diagram of asiphon trap copied from Parkes' hygiene. B is a very diagrammaticoutline of the stomach and duodenum, _a_ is intended to mark theposition of the fibrous band, or musculus suspensorius duodeni; and_b_ the position of entry of the ducts of the liver and pancreas. Theduodenum, then, is a siphon trap, and a most efficient one. Now, theefficiency of a siphon trap depends not only on its shape, but what isabsolutely essential is that the curve must be kept constantly full offluid, without which it ceases to be a trap, and would allow gases toascend freely. The position of the place of entry of the ducts of thepancreas and liver assures that this _sine qua non_ shall be present. The discharge of the secretions of the pancreas and liver, althoughmore active during and after feeding, is practically constant, and soinsures in an admirable manner that the curve on which the efficiencyof the trap depends shall be constantly kept full not only with fluid, but, as I would suggest, antiseptic fluid. There is no other trap inthe intestinal canal, but the peculiar position of the colon would nodoubt have more or less effect in preventing gases ascending throughthe ileo-cæcal valve. --_Lancet. _

 * * * * *

WISCONSIN CRANBERRY CULTURE. 

Among the many thousands of well informed persons with whom thecranberry is a staple article of food throughout the autumn andwinter, and who especially derive from its pungent flavor sharp relishfor their Thanksgiving and Christmas turkey, not one in ten has anydefinite idea as to where the delicious fruit comes from, or of themethod of growing and harvesting it. Most people are, however, awarethat it is raised on little "truck patches" somewhere down in NewJersey or about Cape Cod, and some have heard that it is gleaned fromthe swamps in the Far West by Indians and shipped to market by whitetraders. But to the great majority its real history is unknown. 

Yet the cranberry culture is an industry in which millions of dollarsare invested in this country, and it gives employment, for at least aportion of each year, to many thousands of people. In the East, wherethe value of an acre of even swamp land may run up into the thousandsof dollars, a cranberry marsh of five or ten acres is considered alarge one, and, cultivated in the careful, frugal style in voguethere, may yield its owner a handsome yearly income. But in the great, boundless West, where land, and more especially swamp land, may be hadfor from $1 to $5 an acre, we do these things differently, if notbetter. 

The State of Wisconsin produces nearly one-half of the cranberriesannually grown in the United States. There are marshes there coveringthousands of acres, whereon this fruit grows wild, having done so evenas far back as the oldest tradition of the native red man extends. Inmany cases the land on which the berries grow has been bought from thegovernment by individuals or firms, in vast tracts, and the growth ofthe fruit promoted and encouraged by a system of dikes and damswhereby the effects of droughts, frost, and heavy rainfalls arecounteracted to almost any extent desired. Some of these holdingsaggregate many thousands of acres under a single ownership; and aftera marsh of this vast extent has been thoroughly ditched and goodbuildings, water works, etc. , are erected on it, its value may reachmany thousands of dollars, while the original cost of the land mayhave been merely nominal. 

Large portions of Jackson, Wood, Monroe, Marinette, Juneau, and Greencounties are natural cranberry marshes. The Wisconsin Valley divisionof the Chicago, Milwaukee & St. Paul Railway runs through a closelycontinuous marsh, forty miles long and nearly as wide, as level as afloor, which is an almost unbroken series of cranberry farms. TheIndians, who inhabited this country before the white man came, used tocongregate here every fall, many of them traveling several hundredmiles, to lay in their winter supply of berries. Many thousands ofbarrels are now annually shipped from this region; and thus this vastarea, which to the stranger looking upon it would appear utterlyworthless, is as valuable as the richest farming lands in the State. 

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

One of the best and most perfectly equipped marshes in Wisconsin isowned by Mr. G. B. Sackett, of Berlin. It is situated four miles northof that village, and comprises 1, 600 acres, nearly all of which is averitable bog, and is covered with a natural and luxuriant growth ofcranberry vines. A canal has been cut from the Fox River to thesouthern 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, sufficientto float fair sized steamboats. At the intersection of the canal withthe marsh steam water works have been erected, with flood gates anddams by means of which the entire marsh may be flooded to a depth of afoot or more when desired. There are two engines of 150 horse powereach, and two pumps that are capable of raising 80, 000 gallons perminute. 

When, in early autumn, the meteorological conditions indicate theapproach of frost, the pumps may he put to work in the afternoon andthe berries be effectually covered by water and thus protected beforenightfall. At sunrise the gates are opened and the water allowed torun off again, so that the pickers may proceed with their work. Themarsh is flooded to a depth of about two feet at the beginning of eachwinter and allowed to remain so until spring, the heavy body of icethat forms preventing the upheaval that would result from freezing andthawing--a natural process which, if permitted, works injury to thevines. 

There is a three-story warehouse on the marsh, with a capacity of20, 000 barrels of berries, and four large two-story houses capable offurnishing shelter for 1, 500 pickers. The superintendent's residenceis a comfortable cottage house, surrounded by giant oaks and elms, andstands near the warehouse on an "island, " or small tract of high, dryland near the center of the great marsh. The pickers' quarters standon another island about 200 yards away. 

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

The picking season usually begins about Sept. 1, and from that timeuntil Oct. 1 the marshes swarm with men, women, and children, rangingin age from six to eight years, made up from almost every nationalityunder the sun. Bohemians and Poles furnish the majority of the workingforce, while Germans, Irish, Swedes, Norwegians, Danes, negroes, Indians, and Americans contribute to the motley contingent. They comefrom every direction and from various distances, some of themtraveling a hundred miles or more to secure a few days' or weeks'work. Almost every farmer or woodsman living anywhere in the region ofthe marshes turns out with his entire family; and the families of allthe laboring men and mechanics of the surrounding towns and citiesjoin 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 homeat night, taking their noon-day meal with them, while those from adistance take provisions and bedding with them and camp in thebuildings provided for that purpose by the marsh owners, doing theirown cooking on the stoves and with the fuel furnished them. 

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

Indians are not usually as good pickers as white people, but in thesparsely settled districts, where many of the berry farms aresituated, it is impossible to get white help enough to take care ofthe crop in the short time available for the work, and owners arecompelled to employ the aborigines. A rake, with the prongs shapedlike the letter V, is used for picking in some cases, but owing to thelarge amount of grass and weeds that grow among the vines on thesewild marshes, this instrument is rarely available. After being pickedthe berries are stored in warehouses for a period varying from one tothree weeks. They are washed and dried by being passed through afanning mill made for the purpose, and are then allowed to cure andripen 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, 507bushels, in 1884 24, 738 bushels, in 1885 264, 432 bushels, and in 188670, 686 bushels of this fruit. By these figures it will be seen thatthe yield is very irregular. This is owing, principally, to the factthat many of the marshes are not yet provided with the means offlooding, and of course suffer from worms, droughts, late spring orearly autumn frosts, and extensive fires started by sparks from theengines on railroads running through the marshes. These and variousother evils are averted on the more improved farms. So that, whilehandsome fortunes have in many cases been made in cranberry growing, many thousands of dollars have, on the other hand, been sunk in thesame industry. Only the wealthier owners, who have expended vast sumsof money in improving and equipping their property, can calculate withany degree of certainty on a paying crop of fruit every year. 

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

 * * * * *

SOUDAN COFFEE. 

(_Parkia biglobosa. _)

There are valuable plants on every continent. Civilized Europe nolonger counts them. Mysterious Africa is no less largely andspontaneously favored with them than young America and the ancientterritory of Asia. 

The latter has given us the majority of the best fruits of ourgardens. We have already shown how useful the butter tree(_Butyrospermum Parkii_) is in tropical Africa, and we also know howthe _gourou_ (_Sterculia acuminata_) is cultivated in the sameregions. But that is not all, for the great family of Leguminosæ, whose numerous representatives encumber this continent, likewisefurnishes the negro natives a food that is nearly as indispensable tothem as the _gourou_ or the products of the baobab--another valuabletree and certainly the most widely distributed one in torrid Africa. This leguminous tree, which is as yet but little known in thecivilized world, has been named scientifically _Parkia biglobosa_ byBentham. 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_; inHaoussa, _doroa_; in Hant-fleure (Senegal), _nayraytou_. On the oldmysterious continent it plays the same role that the algarobas do inyoung America. However, it is quite a common rule to find in the orderLeguminosæ, and especially in the section Mimosæ, plants whose podsare edible. Examples of this fact are numerous. As regards theMediterranean region, it suffices to cite the classic carob tree(_Ceratonia siliqua_), which also is of African nationality, but whichis wanting in the warm region of this continent. 

Throughout the tropical region of Africa, the aborigines love toconsume 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 consumedeither 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. Thispreparation has in most cases a pasty form or the consistency ofcohesive flour; but in order to render its carriage easier in certainof the African centers where the trade in it is brisk, it iscompressed into tablets similar to those of our chocolate. As thesetwo products are very little known in Europe, it has seemed to us thatit would be of interest to give a description and chemical analysis ofthem. We shall say but little of the plant, which has sufficientlyoccupied botanists. 

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

The houlle (_Parkia biglobosa_) is a large tree from 35 to 50 feet inheight, with a gray bark, many branches, and large, elegant leaves. The latter are compound, bipinnate (Fig. 7), and have fifty pairs ofleaflets, which are linear and obtuse and of a grayish green. Theinflorescence is very pleasing to the eye. The flowers, say theauthors of the _Floræ Senegambiæ Tentamen_, form balls of a dazzlingred, contracted at the base, and resembling the pompons of ourgrenadiers (Fig. 8). The support of this latter consists only of maleflowers. The fruit that succeeds these flowers is supported by aclub-shaped receptacle. It consists of a large pod, which at maturityis 13 inches in length by 10 in width (Fig. 1). This pod is chocolatebrown, quite smooth or slightly tubercular, and is swollen at thepoints where the seeds are situated. The pods are straight or slightlycurved. The aborigines of Rio Nunez use the pods for poisoning thefishes that abound in the watercourses. We do not know what the natureof the toxic principle is that is contained in these hard pods, but wewell know the nature of the yellowish pulp and of the seeds thatentirely fill the pods. 

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

Although the pulp forms a continuous whole, each seed easily separatesfrom the following and carries with it a part of the pulp thatsurrounds it and that constitutes an independent mass (Fig. 2). Thispulpy substance, formed entirely of oval cells filled with aleurone, consists of two distinct layers. The first, an external one of abeautiful yellow, is from 10 to 15 times bulkier than the internalone, 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 onlyby maceration in water. This fresh pulp has a sweet and agreeablealthough slightly insipid taste. Upon growing old and becoming dry, ittakes on a still more agreeable taste, for it preserves its sweetnessand 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 inchthick. 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 inthe center with a gibbosity limited by a line parallel with themargin, and this has given the plant its specific name of _biglobosa_. The mean weight of each seed is 4½ grains. The skin, though thick, isnot very strong. It consists, anatomically, of four layers (Fig. 5) ofa thick cuticle, _c_; of a zone of palissade cells, _z p_; of a zoneof cells with thick tangential walls arranged in a single row; and ofa zone tougher than the others, formed of numerous cells with thickwalls, without definite form, and filled with a blackish red coloringmatter, _cs_. This perisperm covers an exalbuminous embryo formedalmost entirely of two thick, greenish yellow cotyledons having astrong taste of legumine. 

When examined under the microscope, these cotyledons, the alimentarypart of the seed, have the appearance represented in Fig. 6, where_ep_ is the epidermic layer and _cp_ constitutes the uniformparenchyma of the cotyledonary leaf. This parenchymatous mass consistsof oval cells filled with fatty matter and granules of aleurone. 

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

 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 quantityof matter (nearly 60 per cent. ) formed almost exclusively by sugar. Itis not surprising, from this that this product constitutes a food bothagreeable and useful. 

An analysis of the entire seed, made by the same chemist, has giventhe 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 andsugar, and especially of albuminoid matters (very nutritive), largelyjustifies the use made of them as a food. The innate instinct of thesavage peoples of Africa has thus anticipated the data ofscience. --_La Nature. _

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THE HEIGHT OF SUMMER CLOUDS. 

A knowledge of the heights and movements of the clouds is of muchinterest to science, and of especial importance in the prediction ofweather. The subject has therefore received much attention duringrecent years from meteorologists, chiefly in this country and inSweden. In the last published report of the Meteorological Council for1885-86 will be found an account of the steps taken by that body toobtain cloud photographs; and in the _Meteorologische Zeitschrift_ forMarch last, M. M. Ekholm and Hagstrom have published an interestingsummary of the results of observations made at Upsala during thesummers of 1884-85. They determined the parallax of the clouds byangular measurements made from two stations at the extremities of abase of convenient length and having telephonic connection. Theinstruments used were altazimuths, constructed under the direction ofProf. Mohn, specially for measuring the parallax of the auroraborealis. A full description of these instruments and of thecalculations will be found in the _Acta Reg Soc. Sc. Ups. _, 1884. Theresults now in question are based upon nearly 1, 500 measurements of_heights_; the _motions_ will form the subject of a future paper. Itwas found that clouds are formed at all levels, but that they occurmost 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 oftenaccompanies the cumulo-stratus), 12, 800; cirro cumulus, 21, 000;cirrus, 29, 000 (the highest being 41, 000). The maximum of cloudfrequency was found to be at levels of 2, 300 and 5, 500 feet. 

Generally speaking, all the forms of cloud have a tendency to riseduring the course of the day; the change, excepting for the cumulusform, amounting to nearly 6, 500 feet. In the morning, when the cirrusclouds are at their lowest level, the frequency of their lowestforms--the cirro-cumulus--is greatest; and in the evening, when theheight of the cirrus is greatest, the frequency of its highestforms--the cirro-stratus--is also greatest. With regard to theconnection between the character of the weather and the height of theclouds, the heights of the bases of the cumulus are nearly constant inall conditions. The summits, however, are lowest in the vicinity of abarometric maximum. They increase in the region of a depression, andattain their greatest height in thunderstorms, the thickness of thecumulo stratus stretching sometimes for several miles. The highestforms of clouds appear to float at their lowest levels in the regionof a depression. The forms of clouds are identical in all parts of theworld, as has been shown in papers lately read by the Hon. R. Abercromby before the English and Scottish MeteorologicalSocieties. --_Nature_. 

 * * * * *

ON THE CAUSE OF IRIDESCENCE IN CLOUDS. 

By G. JOHNSTONE STONEY. 

When the sky is occupied by light cirro-cumulus cloud, an opticalphenomenon of the most delicate beauty sometimes presents itself, inwhich the borders of the clouds and their lighter portions aresuffused with soft shades of color like those of mother-of-pearl, among which lovely pinks and greens are the most conspicuous. Usuallythese colors are distributed in irregular patches, just as inmother-of-pearl; but occasionally they are seen to form round thedenser patches of cloud a regular colored fringe, in which the severaltints are arranged in stripes following the sinuosities of the outlineof the cloud. 

I cannot find in any of the books an explanation of this beautifulspectacle, all the more pleasing because it generally presents itselfin delightful summer weather. It is not mentioned in the part ofMoigno's great _Repertoire d'Optique_ which treats of meteorologicaloptics, nor in any other work which I have consulted. It seemsdesirable, therefore, to make an attempt to search out what appears tobe its explanation. 

At the elevation in our atmosphere at which these delicate clouds areformed the temperature is too low, even in midsummer, for water toexist in the liquid state; and accordingly, the attenuated vapor fromwhich they were condensed passed at once into a solid form. Theyconsist, in fact, of tiny crystals of ice, not of little drops ofwater. If the precipitation has been hasty, the crystals will, thoughall small, be of many sizes jumbled together, and in that case thebeautiful optical phenomenon with which we are now dealing will notoccur. But if the opposite conditions prevail (which they do on rareoccasions), if the vapor had been evenly distributed, and if theprecipitation took place slowly, then will the crystals in any oneneighborhood be little ice crystals of nearly the same form and size, and from one neighborhood to another they will differ chiefly innumber and size, owing to the process having gone on longer or takenplace somewhat faster, or through a greater depth, in someneighborhoods than others. This will give rise to the patchedappearance of the clouds which prevails when this phenomenon presentsitself. 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 thebest description of snow crystals formed at low temperatures withwhich I am acquainted. From his observations it appears--(a) thatwhen formed at temperatures several degrees below the freezing point, the crystals, whether simple or compound, are nearly all ofsymmetrical forms; (b) that thin tabular crystals are extremelynumerous, consisting either of simple transverse slices of thefundamental hexagon or, more frequently, of aggregations of theseattached edgewise and lying in one plane; and (c) that, according asatmospheric conditions vary, one form of crystal or another largelypreponderates. A fuller account of these most significant observationsis 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 lamellarcrystals of nearly the same thickness. The tabular plates aresubsiding 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 fallingfeather. It will cause them, if disturbed, to oscillate before theysettle into that horizontal position which flat plates finally assumewhen falling through quiescent air. We shall presently consider whatthe conditions must be, in order that the crystals may be liable to benow and then disturbed from the horizontal position. If thisoccasionally happens, the crystals will keep fluttering, and at anyone moment some of them will be turned so as to reflect a ray from thesun to the eye of the observer from the flat surface of the crystalwhich is next him. Now, if the conditions are such as to producecrystals which are plates with parallel faces, and as they are alsotransparent, part only of the sun's ray that reaches the front face ofthe crystal will be reflected from it; the rest will enter thecrystal, and, falling on the parallel surface behind, a portion willbe there reflected, and passing out through the front face, will alsoreach the eye of the observer. 

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

We have now only to explain how it happens that on very rare occasionsthe colors, instead of lying in irregular patches, form definitefringes round the borders of the cloudlets. The circumstances thatgive rise to this special form of the phenomenon appear to be thefollowing: While the cloud is in the process of growth (that is, solong as the precipitation of vapor into the crystalline statecontinues to take place), so long will the crystals keep augmenting. If, then, a cloudlet is in the process of formation, not only by thespringing up of fresh crystals around, but also by the continuedgrowth of the crystals within it, then will that patch of cloudconsist of crystals which are largest in its central part, andgradually smaller as their situation approaches the outside. Here, then, are conditions which will produce one color round the margin ofthe cloud, and that color mixed with others, and so giving rise toother tints, farther in. In this way there comes into existence thatiris-like border which is now and then seen. 

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

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

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

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

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