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Scientific American Supplement, Vol. XIX, No. 470, Jan. 3, 1885
Author: Various
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[Footnote 1: The curves are obtained by striking the plate lightly with a glass rod.]

We thus have a tangible representation of the magnetic field produced by the magnet in the plane of the glass plate or sheet of paper. The number of these lines, or their density, is at every point proportional to the intensity of the field, and the curves that are traced show their direction. To finish the definition of the field, it remains to determine the direction of these lines of force. Such direction is, by definition, and conventionally, that in which the north pole of a small magnetic needle, free to move in the field, would travel. It results from this definition that the lines of force issue from the north pole of a magnet and re-enter the south pole, since the north pole of a magnet repels the north pole of a needle, and vice versa.

These considerations relative to the direction and intensity of the magnetic field are of the highest importance for the physical theory of magneto-electric machines.

The following is another method of fixing phantoms, as employed by Prof. Bailie, of the Industrial School of Physics and Chemistry of the City of Paris. He begins by forming the phantom, in the usual way, upon paper prepared with ferrocyanide, and exposes it to daylight for a sufficient length of time. The filings form a screen which is so much the more perfect in proportion as it is denser, and, after fixation, there is obtained a negative phantom, that is to say, one in which the parts where the field is densest have remained white.

The same processes of fixation apply equally well to galvanic phantoms, that is to say, to the galvanic fields produced by the passage of a current in a conductor, and which consists of analogous lines of force. The processes may be employed very efficaciously and with certainty of success.—La Nature.

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A CHIPPENDALE SIDEBOARD.



Our illustration this week is of a unique and handsome piece of Chippendale work. The outline is elegant, and the scrollings delicate. The pedestals are peculiar in their form, the panels being carved in draperies, etc. In the frieze are two drawers, with grotesque heads forming the handles. The back is fitted with shaped glass and surmounted by an eagle. The whole forms a very characteristic piece of work of the period, having been made about 1760-1770. As our readers are aware, Thomas Chippendale published his book of designs in 1764, with the object of promoting good French design in this field of art. This piece of furniture was sold at auction lately for 85 guineas.—Building News.

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LIQUEFACTION OF THE ELEMENTARY GASES.

By JULES JAMIN, of the Institute of France.

The earlier experiments of MM. Cailletet and Raoul Pictet in the liquefaction of gases, and the apparatus by means of which they performed the process, were described in the Popular Science Monthly, March and May, 1878. The experiments have since been continued and improved upon by MM. Cailletet and Pictet, and others, with more complete results than had been attained at the time the first reports were published, and with the elucidation of some novel properties of gases, and the disclosure of relations, previously not well understood, between the gaseous and the liquid condition. The experiments of Faraday, in the compression of gases by the combined agency of pressure and extreme cold, left six gases which still refused to enter into the liquid state. They were the two elements of the atmosphere (oxygen and nitrogen), nitric oxide, marsh-gas, carbonic oxide, and hydrogen. Many new experiments were tried before the principle that governs the change from the gaseous to the liquid, or from the liquid to the gaseous form was discovered. Aime sank manometers filled with air into the sea till the pressure upon them was equal to that of four hundred atmospheres; Berthelot, by the expansion of mercury in a thermometer tube, succeeded in exerting a pressure of seven hundred and eighty atmospheres upon oxygen. Both series of experiments were without result. M. Cailletet, having fruitlessly subjected air and hydrogen to a pressure of one thousand atmospheres, came to the conclusion that it was impossible to liquefy those gases at the ordinary temperature by pressure alone. Previously it had been thought that the obstacle to condensing gases by pressure alone lay in the difficulty of obtaining sufficient pressure, or in that of finding a vessel suitable for manipulation that would be capable of resisting it. M. Cailletet's thought led to the discovery of another fundamental property of gases.

The experiments of Despretz and Regnault had shown that the scope of Mariotte's law (that the volume of gases increases or diminishes inversely as the pressure upon them) was limited, and that its limits were different with different substances. Andrews confirmed the observations of these investigators, and extended them. Compressing carbonic acid at 13 deg. C. (55 deg. Fahr.), he found that the rate of diminution in volume increased more rapidly than Mariotte's law demanded, and at a progressive rate. At fifty atmospheres the gas all at once assumed the liquid form, became very dense, and fell to the bottom of the vessel, where it remained separated from its vapor by a clearly defined surface, like that which distinguishes water in the air. Experimenting in the same way with the gas at a higher temperature (21 deg. C. or 70 deg. Fahr.), he found that the same result was produced, but more slowly; and it seemed to be heralded in advance by a more rapid diminution in volume previous to the beginning of the change, which continued after the process had been accomplished; as if an anticipatory preparation for the liquid state were going on previous to the completion of the change. Performing the experiment again at 32 deg. C. (90 deg. Fahr.), the anticipatory preparation and the after-continuation of the contraction were more marked, and, instead of a separate and distinct liquid, wavy and mobile striae were perceived on the sides of the vessel as the only signs of a change of state which had not yet been effected. At temperatures above 32 deg. C. (90 deg. Fahr.), there were neither striae nor liquefaction, but there seemed to be a suggestion of them, for, under a particular degree of pressure, the density of the gas was augmented, and its volume diminished at an increasing rate. The temperature of 32 deg. C. (90 deg. Fahr.) is, then, a limit, marking a division between the temperatures which permit and those which prevent liquefaction; it is the critical point, at which is defined the separation, for carbonic acid, between two very distinct states of matter. Below this point, the particular matter may assume the aspect of a liquid; above it, the gas cannot change its appearance, but enters into the opposite constitution from that of a liquid.

Generally, a liquid has considerably greater density than its vapor. But, if a vessel containing both is heated, the liquid experiences a dilatation which is gradually augmented till it equals and even exceeds that of the gas; whence, of course, an equal volume of the liquid will weigh less and less. On the other hand, a constantly larger quantity of vapor is formed, which accumulates above the liquid and becomes heavier and heavier. Now if the density of the vapor increases, and that of the liquid diminishes, they will reach a point, under a suitable temperature, when they will be the same. There will then be no reason for the liquid to sink or the vapor to rise, or for the existence of any line of separation between them, and they will be mixed and confounded. They will no longer be distinguishable by their heat of constitution. It is true that, in passing into the state of a vapor, a liquid absorbs a great deal of latent heat, but that is employed in scattering the molecules and keeping them at a distance; and there will be none of it if the distance does not increase. We are then, at this stage of our experiments, in the presence of a critical point, at which we do not know whether the matter is liquid or gaseous; for, in either condition, it has the same density, the same heat of constitution, and the same properties. It is a new state, the gaso-liquid state. An experiment of Cagniard-Latour re-enforced this explanation of the phenomena. Heating ether in closed vessels to high temperatures, he brought it to a point where the liquid could be made wholly to disappear, or to be suddenly reformed on the slightest elevation or the slightest depression of temperature accordingly as it was raised just above or cooled to just below the critical point. The discovery of these properties suggested an explanation of the failure of previous attempts to liquefy air. Air at ordinary low temperatures is in the gaso-liquid condition, and its liquefaction is not possible except when a difference exists between the density of the vapor and that of the liquid greater than it is possible to produce under any conditions that can exist then. It was necessary to reduce the temperature to below the critical point; and it was by adopting this course that MM. Cailletet and Raoul Pictet achieved their success. The rapid escape of the compressed gas itself from a condition of great condensation at an extremely low temperature was employed as the agent for producing a greater degree of cold than it had been possible before to obtain. M. Cailletet used oxygen escaping at -29 deg. C. from a pressure of three hundred atmospheres; M. Raoul Pictet, the same gas escaping at -140 deg. from a pressure of three hundred and twenty atmospheres; and both obtained oxygen and nitrogen, and M. Pictet hydrogen, in what they thought was a liquid, and possibly even in a solid form.

Still, it could not be asserted that hydrogen and the elements of the air had been completely liquefied. These gases had not yet been seen collected in the static condition at the bottom of a tube and separated from their vapors by the clearly defined concave surface which is called a meniscus. The experiments had, however, proved that liquefaction is possible at a temperature of below -120 deg. C. (-184 deg. Fahr.). To make the process practicable, it was only necessary to find sufficiently powerful refrigerants; and these were looked for among gases that had proved more refractory than carbonic acid and protoxide of nitrogen. M. Cailletet selected ethylene, a hydrocarbon of the same composition as illuminating gas, which, when liquefied by the aid of carbonic acid and a pressure of thirty-six atmospheres, boils at -103 deg. C. (-153 deg. Fahr.). M. Wroblewski, of Cracow, who had witnessed some of M. Cailletet's experiments, and obtained his apparatus, and M. Olzewski, in association with him, also experimented with ethylene, and had the pleasure of recording their first complete success early in April, 1883. Causing liquid ethylene to boil in an air-pump vacuum at -103 deg. C., they were able to produce a temperature of -150 deg. C. (-238 deg. Fahr.), the lowest that had ever been observed. Oxygen, having been previously compressed in a glass tube, became a permanent liquid, with a clearly defined meniscus. It presented itself, like the other liquefied gases, under the form of a transparent and colorless substance, resembling water, but a little less dense. Its critical point was marked at -113 deg. C. (-171 deg. Fahr.), below which the liquid could be formed, but never above it; while it boiled rapidly at -186 deg. C. (-303 deg. Fahr.). A few days afterward, the Polish professors obtained the liquefaction of nitrogen, a more refractory gas, under a pressure of thirty-six atmospheres, at -146 deg. C. (-231 deg. Fahr.). Long, difficult, and expensive operations were required to produce this result, for the extreme degree of cold it demanded had to be produced by boiling large quantities of ethylene in a vacuum. M. Cailletet devised a cheaper process, by employing another hydrocarbon that rises from the mud of marshes, and is called formene. It is less easily liquefied than ethylene, but for that very reason can be boiled in the air at a lower temperature, or at -160 deg.C. (-256 deg. Fahr.); and at this temperature nitrogen and oxygen can be liquefied in a bath of formene as readily as sulphurous acid in the common freezing mixture.

MM. Cailletet, Wroblewski, and Olzewski have continued their experiments in liquefaction, and acquired increased facility in the handling of liquid ethylene, formene, atmospheric air, oxygen, and nitrogen. M. Olzewski was able to report to the French Academy of Sciences, on the 21st of July, 1884, that by placing liquefied nitrogen in a vacuum he had succeeded in producing a temperature of -213 deg.C. (-351 deg. Fahr.), under which hydrogen was liquefied. Contrary to the suppositions founded on the metallic behavior of this element, that it would present the appearance of a molten metal, like mercury, the liquid had the mobile behavior and the transparency of the hydrocarbons.

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EXAMINATION OF FATS.

The methods employed up to the present in examination of fats, animal and vegetable, are mere reactions lacking general application; scattered throughout the literature, and doubtful with regard to reliability, they are of little or no value to the experimenter—an approximate quantitative examination even of a simple mixture being exceedingly difficult if not impossible, since the qualitative composition of fatty substances is the same, and the separation of the nearer components impracticable. The object of analysis consisted in estimating the accompanying impurities of fat, as, resin, albuminoids, and pigments. The nature of these substances depends on the mode of extraction and preservation of the fat, and are subject in the course of time to alteration. The only reaction based upon the chemical constitution of fat is produced by treatment of oleic or linoleic acid with nitrous acid, which therefore is of some value in the examination of drying oils. Of general application are the methods which correspond to the chemical constitution of fats, and thus determine the relative quantity of the components; advantage can then be derived from qualitative reactions, inasmuch as they further affirm the result of the quantitative test, or dispel any doubt with regard to the correctness of the result. The principal methods which comply with these demands have been carefully studied by Hueble for the purpose of discovering a process of general application; methods founded on the determination of density, freezing, and melting point were compared with those dependent on the solubility of fatty substances in glacial acetic acid or a mixture of alcohol and acetic acid; also the method of Hehner for testing of butter, the determination of glycerine and oleic acid, and at length the process of saponification. Nearly all fats contain members belonging to one of the three series of fatty acids, e.g., acids of the type of acetic acid (stearic and palmitic acids); such as are derivatives of acrylic acid (oleic and erucic acids); and such as are homologues of tetrolic acid (linoleic acid). It is likely that the relative quantity of each of these acids is variable, with regard to the same fat, within definite limits, and changes with the nature of the fatty substance. The groups of fatty acids are distinguished by a characteristic deportment toward halogens; while members of the first series are indifferent to haloids, those of the second and third class combine readily, without suffering substitution, with two respectively four atoms of a haloid. In view of this behavior the first series is termed saturated, the second and third that of unsaturated acids. Addition of halogen to one of the unsaturated acids yields on subsequent examination an invariable quantity of the former, representing two or four atoms, according to one or the other of unsaturated groups; and as the molecular weights of fatty acids are unequal, the percentage quantity of halogen will be found varying with regard to members belonging to the same series. The amount of iodine absorbed by some of the fatty acids is illustrated by the following items:

Hypogallic acid, C_{16}H_{30}O_{2}, combines with 100.00 grammes. iodine. Oleic acid, C_{18}H_{34}O_{2} " " 90.07 " " Erucic acid, C_{22}H_{42}O_{2} " " 75.15 " " Ricinoleic acid, C_{18}H_{34}O_{3} " " 85.24 " " Linoleic acid, C_{16}H_{28}O_{2} " " 201.59 " "

Of the halogens employed in the examination, iodine is preferable to either chlorine or bromine; it acts but slowly at ordinary, but energetically at elevated temperatures. The reagents are solution of mercury iodo-chloride prepared by dissolving of 25 grms. iodine, 500 c.c. alcohol of 95 per cent., and of 30 grms. mercury chloride in an equal measure of the same solvent; both liquids are filtered and united; a standard solution of sodium hyposulphite produced by digestion of 24 grms. of the dry salt with 1 liter water and titration with iodine solution; solution of potassium iodide of 1:10; chloroform, and finally a solution of starch. The above solution of mercury iodo-chloride acts on both free unsaturated acids and glycerides, producing addition products. For testing a sample of 0.2 to 0.4 grm. of a liquid, and from 0.8 to 1.0 grm. of a solid fat being used, which is dissolved in 10 c.c. chloroform and treated with 20 c.c. mercury iodo-chloride solution run into it from a burette, if the liquid appear opalescent a further measure of chloroform is introduced, while the amount of mercury iodo-chloride must be such as to produce a brownish coloration of the chloroform for two subsequent hours. The excess of iodine is determined, on addition of from 10 to 15 c.c. potassium iodide solution and 150 c.c. distilled water, by means of caustic soda. From a burette divided into 0.1 c.c. a solution of caustic soda is poured with continual gyration of the flask into the tinged liquid, and the percentage of combined iodine ascertained by difference; for this purpose 20 c.c. of mercury iodo-chloride are tested, on introduction of a solution of potassium iodide and starch, previously to its use as reagent. Adulteration of solid or semi-liquid fats, especially lard, butter, and tallow, with vegetable oils are readily detected by this method, since the latter yield on examination a high percentage of iodine. Animal fats, absorb comparatively less halogen than vegetable fats, and the power to combine with iodine increases with the transition from the solid to the liquid state, and attains its maximum with vegetable oils—the method being adapted to the examination of fat mixtures containing glycerides and free saturated fatty acids, provided that substances which under similar conditions combine with iodine are absent. These conditions are fulfilled with regard to the examination of animal fats and soap. Ethereal oils are also acted upon by iodine; the reaction proceeds similar to that observed in ordinary fat mixtures. Alcoholic mercury iodo-chloride can probably be used with success in synthetical chemistry, as it allows determination of the free affinities of the molecule and conversion of unsaturated compounds into saturated chlorine-iodo addition products.—Rundschau.

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NOTES ON NITRIFICATION.[2]

[Footnote 2: A paper by R. Warington, read before the Chemical Section of the British Association at Montreal.]

By R. WARINGTON.

In the following brief notes I propose to consider in the first place the present position of the theory of nitrification, and next to give a short account of the results of some recent experiments conducted in the Rothamsted Laboratory.

The Theory of Nitrification.—The production of nitrates in soils, and in waters contaminated with sewage, are facts thoroughly familiar to chemists. It is also well known that ammonia, and various nitrogenous organic matters, are the materials from which the nitric acid is produced. Till the commencement of 1877 it was generally supposed that this formation of nitrates from ammonia or nitrogenous organic matter was the result of simple oxidation by the atmosphere. In the case of soil it was imagined that the action of the atmosphere was intensified by the condensation of oxygen in the pores of the soil; in the case of waters no such assumption was possible. This theory was most unsatisfactory, as neither solutions of pure ammonia, nor of any of its salts, could be nitrified in the laboratory by simple exposure to air. The assumed condensation of oxygen in the pores of the soil also proved to be a fiction as soon as it was put by Schloesing to the test of experiment.

Early in 1877, two French chemists, Messrs. Schloesing and Muentz, published preliminary experiments showing that nitrification in sewage and in soils is the result of the action of an organized ferment, which occurs abundantly in soils and in most impure waters. This entirely new view of the process of nitrification has been amply confirmed both by the later experiments of Schloesing and Muentz, and by the investigations of other chemists, among which are those by myself conducted in the Rothamsted Laboratory.

The evidence for the ferment theory of nitrification is now very complete. Nitrification in soils and waters is found to be strictly limited to the range of temperature within which the vital activity of living ferments is confined. Thus nitrification proceeds with extreme slowness near the freezing-point, and increases in activity with a rise in temperature till 37 deg. is reached; the action then diminishes, and ceases altogether at 55 deg.. Nitrification is also dependent on the presence of plant-food suitable for organisms of low character. Recent experiments at Rothamsted show that in the absence of phosphates no nitrification will occur. Further proof of the ferment theory is afforded by the fact that antiseptics are fatal to nitrification. In the presence of a small quantity of chloroform, carbon bisulphide, salicylic acid, and apparently also phenol, nitrification entirely ceases. The action of heat is equally confirmatory. Raising sewage to the boiling-point entirely prevents its undergoing nitrification. The heating of soil to the same temperature effectually destroys its nitrifying power. Finally, nitrification can be started in boiled sewage, or in other sterilized liquid of suitable composition, by the addition of a few particles of fresh surface soil or a few drops of a solution which has already nitrified; though without such addition these liquids may be freely exposed to filtered air without nitrification taking place.

The nitrifying organism has been submitted as yet to but little microscopical study; it is apparently a micrococcus.

It is difficult to conceive how the evidence for the ferment theory of nitrification could be further strengthened; it is apparently complete in every part. Although, however, nearly the whole of this evidence has been before the scientific public for more than seven years, the ferment theory of nitrification can hardly be said to have obtained any general acceptance; it has not indeed been seriously controverted, but neither has it been embraced. In hardly a single manual of chemistry is the production of saltpeter attributed to the action of a living ferment existing in the soil. Still more striking is the absence of any recognition of the evidence just mentioned when we turn to the literature and to the public discussions on the subjects of sewage, the pollution of river water, and other sanitary questions. The oxidation of the nitrogenous organic matter of river water is still spoken of by some as determined by mere contact with atmospheric oxygen, and the agitation of the water with air as a certain means of effecting oxidation; while by others the oxidation of nitrogenous organic matter in a river is denied, simply because free contact with air is not alone sufficient to produce oxidation. How much light would immediately be thrown on such questions if it were recognized that the oxidation of organic matter in our rivers is determined solely by the agency of life, is strictly limited to those conditions within which life is possible, and is most active in those circumstances in which life is most vigorous. It is surely most important that scientific men should make up their minds as to the real nature of those processes of oxidation of which nitrification is an example. If the ferment theory be doubted, let further experiments be made to test it, but let chemists no longer go on ignoring the weighty evidence which has been laid before them. It is partly with the view of calling the attention of English and American chemists to the importance of a decision on this question that I have been induced to bring this subject before them on the present occasion. I need hardly add that such results as the nitrification of sewage by passing it through sand, or the nitrification of dilute solutions of blood prepared without special precaution, are no evidence whatever against the ferment theory of nitrification. If it is to be shown that nitrification will occur in the absence of any ferment, it is clear that all ferments must be rigidly excluded during the experiments; the solutions must be sterilized by heat, the apparatus purified in a similar manner, and all subsequent access of organisms carefully guarded against. It is only experiments made in this way that can have any weight in deciding the question.

Leaving now the theory of nitrification, I will proceed to say a few words, first, as to the distribution of the nitrifying organism in the soil; secondly, as to the substances which are susceptible of nitrification; thirdly, upon certain conditions having great influence on the process.

The Distribution of the Nitrifying Organism in the Soil.—Three series of experiments have been made on the distribution of the nitrifying organism in the clay soil and subsoil at Rothamsted. Advantage was taken of the fact that deep pits had been dug in one of the experimental fields for the purpose of obtaining samples of the soil and subsoil. Small quantities of soil were taken from freshly-cut surfaces on the sides of these pits at depths varying from 2 inches to 8 feet. The soil removed was at once transferred to a sterilized solution of diluted urine, which was afterward examined from time to time to ascertain if nitrification took place. These experiments are hardly yet completed; the two earlier series of solutions have, however, been examined for eight and seven months respectively. In both these series the soil taken from 2 inches, 9 inches, and 18 inches from the surface has been proved to contain the nitrifying organism by the fact that it has produced nitrification in the solutions to which it was added; while in twelve distinct experiments made with soil from greater depths no nitrification has yet occurred, and we must therefore conclude that the nitrifying organism was not present in the samples of soil taken. The third series of experiments has continued as yet but three months and a half; at present no nitrification has occurred with soil taken below 9 inches from the surface. It would appear, therefore, that in a clay soil the nitrifying organism is confined to about 18 inches from the surface; it is most abundant in the first 6 inches. It is quite possible, however, that in the channels caused by worms, or by the roots of plants, the organism may occur at greater depths. In a sandy soil we should expect to find the organism at a lower level than in clay, but of this we have as yet no evidence. The facts here mentioned are in accordance with the microscopical observations made by Koch, who states that the micro-organisms in the soils he has investigated diminish rapidly in number with an increasing depth; and that at a depth of scarcely 1 meter the soil is almost entirely free from bacteria.

Some very practical conclusions may be drawn from the facts now stated. It appears that the oxidation of nitrogenous matter in soil will be confined to matter near the surface. The nitrates found in the subsoil and in subsoil drainage waters have really been produced in the upper layer of the soil, and have been carried down by diffusion, or by a descending column of water. Again, in arranging a filter bed for the oxidation of sewage, it is obvious that, with a heavy soil lying in its natural state of consolidation, very little will be gained by making the filter bed of considerable depth; while, if an artificial bed is to be constructed, it is clearly the top soil, rich in oxidizing organisms, which should be exclusively employed.

The Substances Susceptible of Nitrification.—The analyses of soils and drainage waters have taught us that the nitrogenous humic matter resulting from the decay of plants is nitrifiable; also that the various nitrogenous manures applied to land, as farmyard manure, bones, fish, blood, rape cake, and ammonium salts, undergo nitrification in the soil. Illustrations of many of these facts from the results obtained in the experimental fields at Rothamsted have been published by Sir J.B. Lawes, Dr. J.H. Gilbert, and myself, in a recent volume of the Journal of the Royal Agricultural Society of England. In the Rothamsted Laboratory, experiments have also been made on the nitrification of solutions of various substances. Besides solutions containing ammonium salts and urea, I have succeeded in nitrifying solutions of asparagine, milk, and rape cake. Thus, besides ammonia, two amides, and two forms of albuminoids have been found susceptible of nitrification. In all cases in which amides or albuminoids were employed, the formation of ammonia preceded the production of nitric acid. Mr. C.F.A. Tuxen has already published in the present year two series of experiments on the formation of ammonia and nitric acids in soils to which bone-meal, fish-guano, or stable manure had been applied; in all cases he found the formation of ammonia preceded the formation of nitric acid.

As ammonia is so readily nitrifiable, we may safely assert that every nitrogenous substance which yields ammonia when acted upon by the organisms present in soil is also nitriflable.

Certain Conditions having Great Influence in the Process of Nitrification.—If we suppose that a solution containing a nitrifiable substance is supplied with the nitrifying organism, and with the various food constituents necessary for its growth and activity, the rapidity of nitrification will depend on a variety of circumstances:

1. The degree of concentration of the solution is important. Nitrification always commences first in the weakest solution, and there is probably in the case of every solution a limit of concentration beyond which nitrification is impossible.

2. The temperature has great influence. Nitrification proceeds far more rapidly in summer than winter.

3. The presence or absence of light is important. Nitrification is most rapid in darkness; and in the case of solutions, exposure to strong light may cause nitrification to cease altogether.

4. The presence of oxygen is of course essential. A thin layer of solution will nitrify sooner than a deep layer, owing to the larger proportion of oxygen available. The influence of depth of fluid is most conspicuous in the case of strong solutions.

5. The quantity of nitrifying organism present has also a marked effect. A solution seeded with a very small amount of organism will for a long time exhibit no nitrification, the organism being (unlike some other bacteria) of very slow growth. A solution receiving an abundant supply of the ferment will exhibit speedy nitrification, and strong solutions may by this means be successfully nitrified, which with small seedings would prove very refractory. The speedy nitrification which occurs in soil (far more speedy than in experiments in solutions under any conditions yet tried) is probably owing to the great mass of nitrifying organisms which soil contains, and to the thinness of the liquid layer which covers the soil particles.

6. The rapidity of nitrification also depends on the degree of alkalinity of the solution. Nitrification will not take place in an acid solution; it is essential that some base should be present with which the nitric acid may combine; when all available base is used up, nitrification ceases.

It appeared of interest to ascertain to what extent nitrification would proceed in a dilute solution of urine without the addition of any substance save the nitrifying ferment. As urea is converted into ammonium carbonate in the first stage of the action of the ferment, a supply of salifiable base would at first be present, but would gradually be consumed. The result of the experiment showed that only one-half the quantity of nitric acid was formed in the simple urine solution as in similar solutions containing calcium and sodium carbonate. The nitrification of the urine had evidently proceeded until the whole of the ammonium had been changed into ammonium nitrate, and the action had then ceased. This fact is of practical importance. Sewage will be thoroughly nitrified only when a sufficient supply of calcium carbonate, or some other base, is available. If, instead of calcium carbonate, a soluble alkaline salt is present, the quantity must be small, or nitrification will be seriously hindered.

Sodium carbonate begins to have a retarding influence on the commencement of nitrification when its amount exceeds 300 milligrammes per liter, and up to the present time I have been unable to produce an effective nitrification in solutions containing 1.000 gramme per liter.

Sodium hydrogen carbonate hinders far less the commencement of nitrification.

Ammonium carbonate, when above a certain amount, also prevents the commencement of nitrification. The strongest solution in which nitrification has at present commenced contained ammonium carbonate equivalent to 368 milligrammes of nitrogen per liter. This hinderance of nitrification by the presence of an excess of ammonium carbonate effectually prevents the nitrification of strong solutions of urine, in which, as already mentioned, ammonium carbonate is the first product of fermentation.

Far stronger solutions of ammonium chloride can be nitrified than of ammonium carbonate, if the solution of the former salt is supplied with calcium carbonate. Nitrification has in fact commenced in chloride of ammonium solutions containing more than two grammes of nitrogen per liter.

The details of the recent experiments, some of the results of which we have now described, will, it is hoped, shortly appear in the Journal of the Chemical Society of London.

Harpenden, July 21.

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ANILINE DYES IN DRESS MATERIALS.

By Professor CHARLES O'NEILL.

Twenty-eight years ago Mr. Perkin discovered the first of the aniline dyes. It was the shade of purple called mauve, and the chief agent in its production was bichromate of potash. This salt is not actively poisonous, and no one thought of attributing injurious properties to materials dyed with the aniline mauve. Next in chronological order came magenta red. It was first made from aniline by the agency of mercurial salts, and afterward by that form of arsenic known to chemists as arsenic acid. The fact that this at one time fashionable color was prepared by means of an arsenical compound was spread through the country in a very impressive manner by the great trial as to whether the patent was valid or not, all turning upon the expression in the specification of "dry arsenic acid," and the disputes of scientists whether this expression meant arsenic acid with or without water. The public mind had been for some time previously exercised and alarmed by accounts of sickness and debility caused by arsenical paper-hangings; it was, therefore, easy for pseudo scientists to create an opinion that the magenta dye must be also poisonous, and that persons wearing materials dyed with this color were liable to absorb arsenic and suffer from its action. Ever since there have been, at intervals, statements more or less circumstantial, that individuals have suffered from wearing materials dyed with some of the artificial dyes. At the present time these statements are emphasized by the exhibition at the Healtheries of models of skin diseases said to be actually produced by the wearing of dyed garments. Whether it be true or not that any form of skin disease has been produced by the wearing of dyed articles of clothing is simply a question of evidence, and there is evidence enough to show that individuals have experienced ill effects who have worn clothing dyed with artificial colors. But, as far as we know, there is an entire want of any evidence that will satisfactorily show that the inconvenience suffered by wearers of these dyed goods has been owing to the dyeing material. Years must elapse before chemists or physicians can hope to become thoroughly informed of the physiological action produced by the cutaneous absorption of the thousands of new products which the ingenuity and industry of technological chemists have made available for the manufacture of colors; they are also new to science, most of them very complex in their constitution, and so dissimilar to previously studied compounds used by the dyer, that it may be said we have nearly everything to learn concerning their action upon the human economy. With respect to dyed woolen and silk goods it is almost entirely a question as to the innocence or otherwise of the coloring matter itself, which in nine cases out of ten is an organic body containing no mineral matter of any sort, and not requiring the assistance of any mordant to enable it to dye. Considerations of arsenic, or antimony, or mercury existing in the dyed stuffs are absolutely excluded. In a few cases the dyestuff is a zinc compound, and zinc in small traces may possibly be fixed by the material, but this metal is not known to be actively noxious. Textiles made from fibers of animal origin do not require, and as a rule do not tolerate, the addition of any metal in dyeing with the artificial colors, and if the manufacture of the color require the use of a metal, such as arsenic, which by unskillfulness or carelessness is left in it when delivered to the dyer, the tendency of the animal fiber is to reject it.

But the case with regard to textiles made from vegetables fibers is quite different; upon materials made from cotton, flax, jute, or other fiber of the vegetable kingdom, the new aniline colors cannot be fixed without the assistance of other bodies acting the part of mordants. Some of these bodies are actively poisonous in their nature, and introduce a possible element of danger to the wearer of the dyed article. For many years, almost the only method of dyeing cotton goods with the aniline colors consisted in a preliminary steeping in sumac or tannic acid, followed by a passage in some suitable compound of tin, and subsequent dyeing in the coloring matter. Sumac and tin have been used for two hundred years or more as the dyer's basis for a considerable number of shades of color from old dye-stuffs; there never has been the least suspicion that there was anything hurtful in colors so dyed. Sumac or tannic acid, in combination with alumina, may be held to be equally inoffensive; now it is a fact that the great bulk of cotton goods are dyed with the aniline colors by the agency of these harmless chemicals. But of late years the dyers of certain goods, and the calico printers generally, have found an advantage in the use of tartar emetic, and other compounds of antimony, to fix aniline colors; besides this, some colors are fixed in calico printing by means of an arsenical alumina mordant; it need not be mentioned that antimony, as well as arsenic, is, when administered internally, an active poison in even small quantities, and that externally both are injurious under certain conditions. An alarmist would require nothing further than this statement to feel himself justified in attributing everything bad to fabrics so colored; but the practical dyer or calico printer knows that though he employs these poisonous bodies in his business, and that some portion of them does actually accompany the dyed material in its finished state, not only is the quantity excessively small, but that it is in such a state of combination as to be completely inert and innoxious. In the case of tartar emetic, it is the tannate of antimony which remains upon the cloth, a compound of considerable stability, and almost perfectly insoluble in water; in the case of a few colors fixed by the arsenical alumina mordant, the arsenic is in an insoluble state of combination with the alumina, in fact, the poisons are in the presence of their antidotes, and not even the most scrupulous manufacturer has any fear that he is turning out goods which can be hurtful to the wearer. Persons quite unacquainted with the process of dyeing are apt to think that goods are dyed by simply immersing them in a colored liquid and then drying them with all the color on them and all that the color contains; they do not know that in all usual cases of dyeing a careful washing in a plentiful supply of water is the final process in the dye-house, and that nothing remains upon the cloth which can be washed out by water, the color being retained by a sort of attraction or affinity between it and the fiber, or mordant on the fiber. Dyeing is not like painting or even the printing or staining of paper for hangings, where the vehicle and color in its entirety is applied and remains. It follows, therefore, that many chemicals used in dyeing have only a transitory use, and are washed away completely—such as oil of vitriol, much used in woolen dyeing—and that of others only a very minute quantity is finally left on the cloth, as is the case in antimony and arsenic in cotton dyeing and printing.

There is evidently among working dyers, as among all other classes, an unknown amount of carelessness, ignorance, and stupidity, from which employers are constantly suffering in the shape of spoiled colors and rotted cloth. It is not for us to say that the public may not at times have to suffer also from neglect of the most common treatments which should remove injurious matters from dyed goods; what can be said is, that if the dyeing processes for aniline colors be followed out with ordinary care and intelligence, it is extremely improbable that anything left in the material should be injurious to human health.—Manchester Textile Recorder.

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CASE OF RESUSCITATION AND RECOVERY AFTER APPARENT DEATH BY HANGING.

By ERNEST W. WHITE, M.B. Lond., M.R.C.P., Senior Assistant Medical Officer to the Kent Lunatic Asylum; Associate, Late Scholar, of King's College, London.

The following case, from its hopelessness at the outset, yet ultimate recovery under the duly recognized forms of treatment, is of such interest as to demand publicity, and will afford encouragement to others in moments of doubt.

M.A. S——, aged fifty-three, was admitted into the Kent Lunatic Asylum at Chartham on Oct. 3, 1882, suffering from melancholia, the duration of which was stated to have been three months. She had several times attempted suicide by drowning and strangulation. She was on admission ordered a mixture containing morphia and ether thrice daily, to allay her distress. On Oct. 10 she attempted suicide by tying a stocking, which she had secreted about her person, round her neck. Shortly afterward, with similar intent, she threw herself downstairs. On Jan. 4, 1883, she attempted to strangle herself with her apron. On the 30th of November following, at 4 P.M. she evaded the attendants, and made her way to the bath-room of of No. 1 ward, the door of which had been left unfastened by an attendant. She then suspended herself from a ladder there by means of portions of her dress and underclothing tied together. A patient of No. 1 ward discovered her suspended from the ladder eight minutes after she had last seen her in the adjoining watercloset, and gave the alarm.

The woman was quickly cut down, and the medical officers summoned. In the interval cold affusion was resorted to by the attendant in charge, but the patient was to all appearances dead. The junior assistant medical officer, Mr. J. Reynolds Salter, M.B. Lond., arrived after about three minutes, and at once resorted to artificial respiration by the Silvester method. A minute or so later the medical superintendent and myself joined him. At this time the condition of the patient was as follows: The face presented the appearance known as facies hippocratica: the eyeballs were prominent, the corneae glassy, the pupils widely dilated, not acting to light, and there was no reflex action of the conjunctivae; the lips were livid, the tongue tumefied, but pallid, the skin ashy pale, the cutaneous tissues apparently devoid of elasticity. There was an oblique depressed mark on the neck, more evident on the left side; the small veins and capillaries of the surface of the body were turgid with coagulating blood the surface temperature was extremely low. She was pulseless at the wrists and temples. There was no definite beat of the heart recognizable by the stethoscope.

There was absolute cessation of all natural respiratory efforts, complete unconsciousness, total abolition of reflex action and motion, and galvanism with the ordinary magneto-electric machine failed to induce muscular contractions. The urine and faeces had been passed involuntarily during or immediately subsequent to the act of suspension. As the stethoscope revealed that but a small amount of air entered the lungs with each artificial inspiration, the tongue was at once drawn well forward, and retained in that position by an assistant, with the result that air then penetrated to the smaller bronchi. Inspiration and expiration were artificially imitated about ten times to the minute. In performing expiration the chest was thoroughly compressed. The lower extremities were raised, and manual centripetal frictions freely applied. In the intervals of these applications warmth to the extremities was resorted to.

About ten minutes from the commencement of artificial respiration we noticed a single weak spasmodic contraction of the diaphragm, the feeblest possible effort at natural respiration. Simultaneously, very distant weak reduplicated cardiac pulsations, numbering about 150 to the minute, became evident to the stethoscope. The reduplication implied that the two sides of the heart were not acting synchronously, owing to obstruction to the pulmonary circulation induced by the asphyxiated state. Artificial respiration was steadily maintained, and during the next half hour spasmodic contractions of the diaphragm occurred at gradually diminishing intervals, from once in three minutes to three or four times a minute.

These natural efforts were artificially aided as far as possible. At 5:45 P.M. natural respiration was fairly though insufficiently established, the skin began to lose its deadly hue, and titillation of the fauces caused weak reflex contractions. Flagellation with wet towels was now freely resorted to, and immediately the natural efforts at respiration were increased to twice their previous number. The administration of a little brandy and water by the mouth failed, as the liquid entered the larynx. Ammonia was applied to the nostrils, and the surface temperature was increased by warm applications and clothing. At 6 P.M. artificial respiration was no longer necessary. The heart sounds then numbered 140 to the minute, the right and left heart still acting separately. A very small radial pulse could also be felt. At 6:45 P.M. the woman was put to bed, warmth of surface maintained, and hot coffee and beef-tea given in small quantities.

Great restlessness and jactitation set in with the renewal of the circulation in the extremities. An enema of two ounces of strong beef-tea was administered at 10 P.M. The amount of organic effluvium thrown off by the lungs on the re-establishment of respiration was very great and tainted the atmosphere of the room and adjoining ward. The pupils, previously widely dilated, began to contract to light at 11 P.M. Imperfect consciousness returned at 5 P.M. the following day (Dec. 1), and about an hour later she vomited the contents of the stomach (bread, etc., taken on Nov. 30). Small quantities of beef-tea were given by the mouth during the night. At 9 A.M. air entered the lungs freely, and there were no symptoms of pulmonary engorgement beyond slight basic hypostasis; the pulse remained at 140, and the heart sounds reduplicated; she was semiconscious, very drowsy, in a state of mental torpor, with confused ideas when roused, and she complained of rheumatic-like pains all over her.

The temperature was 100.2 deg.; the facial expression more natural; the tongue remained somewhat swollen and sore; she was no longer restless; she took tea, beef-tea, milk, etc., well; the functions of the secreting organs were being restored; she perspired freely; had micturated; the mucous membrane of the mouth was moist, and there was a tendency to tears without corresponding mental depression. The patient was ordered a mixture of ether and digitalis every four hours. On December 2 the pulse was 136, and the heart sounds reduplicated. The following day she was given bromide of potassium in place of the ether in the digitalis mixture. On the 4th the pulse was 126; reduplication gone. On the 6th the pulse was 82, and the temperature fell with the pulse rate. She was well enough to get into the ward for a few hours. Her memory, especially for recent events, was at that time greatly impaired. On the 12th she still complained of muscular pains like those of rheumatism. Apart from that, she was enjoying good bodily health.

A curious fact in connection with this case is that since this attempt at suicide she has steadily improved mentally, has lost her delusions, is cheerful, and employs herself usefully with her needle. She converses rationally, and tells me she recollects the impulse by which she was led to hang herself, and remembers the act of suspension; but from that time her memory is a blank, until two days subsequently, when her husband came to see her, and when she expressed great grief at having been guilty of such a deed. Her bodily health is now (June 30, 1884) more robust than formerly, and she is on the road to mental convalescence.

Remarks.—The successful issue of this case leads me to draw the following inferences: 1. That in cases of suspended animation similar to the above there is no symptom by which apparent can be distinguished from real death. 2. That in artificial respiration alone do we possess the means of restoring animation when life is apparently extinct from asphyxia, and that, with the tongue drawn well forward and retained there by the hand or an elastic band, the Silvester method is complete and effective. 3. That artificial respiration may be necessary for two hours or more before the restoration of adequate natural efforts, and that the performance of the movements ten times to the minute is amply sufficient, and produces a better result than a more rapid rate. 4. That galvanism, ammonia to the nostrils, cold affusion, and stimulants by the mouth are practically useless in the early stage. 5. That on the re-establishment of the reflex function we possess a powerful auxiliary agent in flagellation with wet towels, etc. 6. That centripetal surface frictions and the restoration of the body temperature by warm applications aid recovery. 7. That the heart, if free from organic disease, has great power of overcoming the distention of its right cavities and the obstruction to the pulmonary circulation, although its action may for a time be seriously deranged, as evidenced by reduplication of its sounds. 8. That when the heart's action remains excessively feeble, and the right and left heart fail to contract synchronously, it would be justifiable to open the external jugular vein. 9. That during recovery the lungs are heavily taxed in purifying the vitiated blood, as shown by the excessive amount of organic impurities exhaled. 10. That restlessness and jactitation accompany the restoration of nerve function, and that vomiting occurs with returning consciousness. 11. That pains like those of rheumatism are complained of for some days subsequently, these probably resulting from the sudden arrest of nutrition in the muscles.

Chartham, near Canterbury.

Lancet.

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THE INVENTORS' INSTITUTE.

The twenty-second session of the Inventors' Institute was opened on October 27, the chair being taken by Vice-Admiral J.H. Selwyn, one of the vice-presidents, at the rooms of the institute, Lonsdale Chambers, 27 Chancery Lane, London. The chairman, in delivering the inaugural address, said that in the absence of their president, the Duke of Manchester, it became his duty to open the session of 1885. The institute having been established in 1862, this was their twenty-second anniversary. At the time of its establishment a greater number of members were rapidly enrolled than they could now reckon, although a large number had joined since the commencement of the present year. In 1862 a considerable amount of enthusiasm on the part of inventors had arisen, from the fact that at that time the leading journals had advocated the views of certain manufacturers as to sweeping away the patent laws, enacted anew in 1852, and with them the sole protection of the inventive talent and industry of the nation. This naturally caused much excitement and interest among those chiefly concerned, and a very numerous body of gentlemen associated themselves together and formed an institute for the purpose mainly of resisting the aggression and inculcating views more in accordance with true principles, as well as for explaining what were the true relations of inventive genius to the welfare of the state. He hoped to be able to show strong reasons for this action, and for energetically following it up in the future. Although on that evening there were many visitors present besides the members of the institute, yet he thought the subject could be shown to be of such national importance that it might justly engage the attention of any assembly of Englishmen, to whatever mode of thought they might belong. The institute had persistently done its work ever since its formation. Sometimes it had failed to make itself heard, at others it had been more successful in so doing; but the net result of its labors—and he did not fear to claim it as mainly due to those labors—had been to propagate and spread abroad a fact and a feeling entirely opposed to the false doctrines previously current on the subject, namely, that among our most valuable laws were those which could excite the intelligence and reward the labors of the inventors of all nations. There were still those who wished to see the patent laws swept away, but their numbers had dwindled into a miserable minority, composed mainly of manufacturers who were so curiously short-sighted as not to see that all improvement in manufactures must come from inventive talent, or those who, still more blind, could not perceive that property created by brains was certainly not a monopoly, and deserves protection quite as much as any other form of possession, in order that it may be developed by capital. He need scarcely waste time in pointing out the fallacy of refusing to pay for the seed corn of industrial pursuits, for that fallacy, bit by bit, had been completely swept away, and last year the labors of the institute had been so far crowned with success that the President of the Board of Trade, in his place in Parliament, announced his conviction that "inventors were the creators of trade, and ought to be encouraged and not repressed." Such a conviction, forced home in such a quarter, ought to have produced a great and beneficial change in the legislation on the subject, and the hopes of inventors were that this would surely be the case; but when the bill appeared these hopes were considerably depressed, and now, after a year's experience of the working of the changed law, scarcely any benefit appears to have been obtained, beyond the meager concession that the heavy payments demanded, for an English patent may be made in installments instead of lump sums. Against this infinitesimal concession had to be set a number of disabilities which did not formerly exist, such as compulsory licenses, which disinclined the capitalist to invest in inventions, attempts to assimilate the provisional specification to the complete, or to restrict the latter within the terms of the former, attempts to separate the parts of an invention, and thus increase the number of patents required to protect it, and many other minor annoyances which would take too much time to explain fully. It was true that there was some extension of the time for payment—some such locus penitentiae as would be accorded to any debtor by any creditor in the hope of getting the assets; but the promised spirit of encouragement to inventors was not to be found in the bill; it was still a boon which must be earnestly sought by the institute.

He had said that the concessions granted were almost infinitesimal, yet a result had been obtained, surprisingly confirmatory of the views always advocated by the institute as to the potentiality of the inventive talent of this nation were it released from its shackles. While in former years the highest number of patents taken out had slowly risen to the number of five to six thousand per annum, in the year now expiring it had bounded to more than three times five thousand—had at one leap reached an equality with the patents of the United States, where only L4 ($20) was paid for a patent for seventeen years, instead of L175, as in Great Britain, for a term of fourteen years. If in the future we could hope to persuade the legislators to be content with no heavier tax than in the United States had yielded a heavy surplus over expenses of a well-conducted Patent Office, he did not fear to assert that the number of patents taken out in this country would again be trebled, and that trade and industry would be correspondingly animated and developed. The result of the wiser patent law of the United States had been to flood our markets with well-manufactured yet cheap articles from that country which might have been equally well made by our artisans at home had invention not been subject to such heavy restrictions, and had technical skill been equally sure of its reward.

The business of the institute in the future was not to rest satisfied with the proposition of Mr. Chamberlain, but to lead him or his successors forward by logical and legitimate means toward the necessary corollary of that proposition. If inventors were indeed the creators of trade, then the President of the Board of Trade was bound to see, not only that they were not prevented from creating trade, but that they received every facility in performing their work. Hence all exertions should be used to convince the Chancellor of the Exchequer that a less tax may produce a greater income: to persuade the legal authorities that this description of property, of all others, most deserves the protection of the law. Inherited direct from the Giver of all good gifts, no person had been dispossessed of anything he previously owned, and the wealth of humanity might be indefinitely increased by means of it. Not many mighty, not many noble, received this gift, but it was the inexhaustible heritage of the humble, it was the rich reward of the intelligent of all races that peopled the earth. To whomsoever given, this gift was intended to contribute to the health and the wealth of the human race, for the bringing into existence new products, for their utilization for the encouragement of the general intelligence of the nations, and for the lightening of the burdens of the poor. It would also cause technical education to be more highly valued as a means to an end—for true inventive genius was never so likely to succeed as when it passed from the summit of the known to the confines of the possible, when, having learnt and appreciated what predecessors had accomplished, it went earnestly to work to solve the next problem, to remove the next obstacle on the path which to them had proved insurmountable.

More beneficial than any other change whatever in our legislation would be a full and cordial recognition, a complete and efficient protection, of property created by thought. Then the humblest individual in the land might have confidence that he could call into existence property not inferior in value to that of the richest landowner, the most successful merchant, or the most wealthy manufacturer, in the whole world. As an instance of this Admiral Selwyn mentioned two prominent cases arising out of the pursuit of two widely differing branches of knowledge, in the one case by an outsider, in the other by a specialist. He referred to Sir H. Bessemer, one of his valued colleagues in the vice-presidency of the institute, and Mr. Perkins, the discoverer of aniline dyes. In each of these instances, whatever might have been the results to the inventors, and he hoped they had been satisfactory, a sum which might be estimated at twenty millions sterling annually, constantly on the increase, and never before existing, had been added to the income-tax-paying wealth of the country. With such a result arising from the development of only two inventions, he thought it would be seen that he must be a most ignorant, foolish, or obstinate Chancellor of the Exchequer who would refuse to allow such property to be created by requiring heavy preliminary payments, or in any way discourage or fail to encourage to the utmost of his power the creation of property which was capable of producing such a result—a result which he would in vain seek for did he rely on landed property alone, since this, in the hands of whomsoever it might be, never could largely increase in extent, and was subject at this moment to serious depreciation in tax-paying power.

The exertion of intelligence, combined with a sense of security in its pecuniary results, was in itself opposed to loose notions of proprietary rights, and tended to diminish that coveting of neighbors' goods which was the fertile source of vice and crime, and which was capable of breaking down the strongest and most wealthy community if indulged, till at last society was resolved into its elements, and when nothing else was left as property, man, the savage, coveted the scalp of his fellow man, and triumphed over a lock of hair torn from his bleeding skull.

Invention was an ennobling pursuit, and was, even among those who were not also handworkers, a means of employment which never left dull or idle hours, while to the handworker it meant more, for it offered the most ready means of rising among his fellows, and, where invention received proper protection, of securing a competence for old age or ill health. Not only, as he had before said, did the results of invention cause no loss to any other individual, unless by displacing inferior methods of working, but in most instances some distinct benefit arose to the whole human race, and unless this was the case the patented invention failed to obtain recognition, soon died out, and left the field clear for others to occupy.

He regretted that so few results had been obtained from the Patent Bill of last year, but he would briefly refer to some of the changes thought desirable by inventors and by the council of the institute.

No one could deem it desirable, it could scarcely be thought reasonable, that an Englishman who was called upon to pay in the United States L7 for a valid patent for seventeen years should be still obliged in his own country to pay L175 for a less term of a patent which does not convey anything but a right to go to law. It was also not reasonable to pretend by a deed to convey a proprietary right while reserving the power to grant compulsory licenses, which must tend to destroy the value of such proprietary right.

It was a reproach to legislative perspicacity that the grantee of a patent should be obliged to accept the view of the state, the grantor, as to the value of the invention to the nation, and also that any other method of proceeding to upset a patent, once granted, should be allowed than a suit for revocation to the crown, on the ground of error, such revocation if obtained not to prejudice the granting anew, with the old date, of a valid patent for the parts of the invention which are not proved to be anticipated at the trial. There are many other points which could not be referred to on the present occasion, but he might say that the duty of the council would be to press them forward until the capitalist could consider patented property at least as sound an investment as any other. So might the wealth of the nation be largely increased, and the sense of justice between man and man be more fully inculcated. In the United States inventors were able at once to secure the favorable attention of capitalists, because there the whole business of the Patent Office was to assist the inventor to obtain a valid—and, as far as possible, an indisputable—patent.

Even so small an article as a pair of pliers, one of the most familiar of tools, had been proved to be capable of patented improvement. Formerly these were always made to open and close at an angle which precluded their holding any object grasped by them with the desirable rigidity. A clever workman invented a means of producing this effect by the application of a parallel motion. He probably went to the office at Washington, was referred to a certain room in a certain corridor, and there found a gentleman whose business it was to know all about the patents for such tools. By his aid he eliminated from his patent all anticipatory matter, and issued from the office with a valid patent, which, developed by capital, had supplied all the trades which employ such instruments with a better means of accomplishing their work, had employed capital and labor with remunerative results in producing the pliers, and had added one more to the little things which create trade for his country.

This was a typical instance of the way in which invention was encouraged in America. Why should it be otherwise here? For many years literary property had received a protection which was yet to be desired for patented invention. Not only for fourteen years, but for the duration of a man's life, was that kind of brain property protected, and even after his death his heirs still continued to derive benefit from it. Should a romance or a poem be deemed more worthy of reward than the labors of those inventors to whom he had referred, and which certainly produced far greater and more abiding advantage to the nation? To secure a due appreciation of the whole importance of invention, no other means could be adopted than that which the institute had been formed to secure, namely, the union of inventors, not only of one nation, but of the whole world. The international character of the subject had been recognized by the institute, and they had never neglected any opportunities of pressing that view of the subject, which had at last obtained some recognition from our government.

No great result could, however, be expected from a congress where inventors, not lawyers or patent agents, still less officials trained in a vicious routine, formed the majority. It might be hoped that next year there would arise an opportunity for such a congress, and that the institute would do its best to improve the occasion. There never had been a time when England more required the creation of new industries. Our agriculturists had signally failed to hold their own in the face of unlimited competition, and the food of the nation no longer came from within. But if that were the case, then some means must be found of paying for the food imported from abroad, and this could only be done by constant improvement in manufactures, or some change by which we might sell some of our other productions at a profit if the food could not be produced but at a loss. Here invention might fitly be called to aid, but could only respond if all restrictions were removed and every facility granted.

Capital must be induced to consider that home investments are more remunerative and not less secure than any others, and this could only be done by adding to the security of the property proposed for investment. He had referred to the unlimited nature of the property created by invention, and they would infer that if properly protected there was equally no limit to the capital that could be profitably employed in developing such property. The institute did not exist solely or even mainly for the purpose of advocating the claims of inventors to consideration, either individually or collectively, but for the great object of forcing home upon the convictions of the people the fact that at the very foundation of the wealth and prosperity of every nation lies the intelligence, the skill, the honesty, and the self-denial of its sons.

If, when these were exercised, for want of wise legislation such virtues failed to secure their due reward, they sought a more genial clime, and that nation which had undervalued them sank to rise no more; or, if the error were acknowledged, and too late the course was reversed, found itself already outstripped in the race of progress, and could slowly, if ever, regain its lost position. Finally he urged the inventors of England to rally round the institution in all their strength, and thus secure the objects of which he had striven, however feebly, to point out the importance. If they did so, this institution would take a rank second to no other in the empire: and while acknowledging that the interests of the inventor must always be subordinate to the welfare of the state, he asserted that the two were inseparable, and that in no other way could the latter and principal result be so completely secured as by according a due consideration to the former.

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THE NEW CENTRAL SCHOOL AT PARIS.

We present herewith, from L'Illustration, views of the amphitheater, and first and second year laboratories of the new Central School at Paris.



The amphitheater does not perceptibly differ from those of other schools. It consists of a semicircle provided with rows of benches, one above another, upon which the pupils sit while listening to lectures and taking notes thereof. Several blackboards, actuated by hydraulic motors, serve for demonstration by the professor, who, if need be, will be enabled, thanks to the electricity and gas put within his reach, to perform experiments of various kinds. Electricity is brought to him by wires, just as water and gas are by pipes. It will always be possible for him to support the theory that he is explaining by experiments which facilitate the comprehension of it by the pupils. The amphitheater is likewise provided with a motor which furnishes the professor with power whenever he has recourse to a mechanical application.

It will not be possible for the pupils to have their attention distracted by what is going on outside of the amphitheater, since the architect has taken the precaution to use ground glass in the windows.



As regards the laboratories, it is allowable to say that they constitute the first great school of experimental chemistry in France. The first year laboratory consists of a series of tables, provided with evaporating hoods, at which a series of pupils will study general chemistry experimentally. Electricity, and gas and water cocks are within reach of each operator, and all the deleterious emanations from the acids that are used or are produced in studying a body will escape through the hoods.

The third year laboratory is designed for making commercial analyses. These latter are made by either dry or wet way. The first method employs water chiefly as a vehicle, and alkaline solutions as reagents. The second employs reagents in a dry state, and the action of which requires lamp and furnace heat. The furnaces employed in the new school are like those almost exclusively used industrially for the analysis of ores. The tables upon which analyses by dry way are made are large enough to allow sixteen pupils to work.



Analyses by wet way are made upon tables, with various sorts of vessels. Along with water, gas, and electricity, the pupils have at their disposal a faucet from whence they may draw the hydrosulphuric acid which is so constantly used in laboratory operations.

The architect of the new school is Mr. Denfer.

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[NATURE.]

RESEARCHES ON THE ORIGIN AND LIFE-HISTORIES OF THE LEAST AND LOWEST LIVING THINGS.

By Rev. W.H. DALLINGER, LL. D.

To all who have familiarized themselves, even cursorily, with modern scientific knowledge, it is well known that the mind encounters the infinite in the contemplation of minute as well as in the study of vast natural phenomena. The farthest limit we have reached, with the most gigantic standard of measurement we could well employ, in gauging the greatness of the universe, only leaves us with an overwhelming consciousness of the awful greatness—the abyss of the infinite—that lies beyond, and which our minds can never measure. The indefinite has a limit somewhere; but it is not the indefinite, it is the measureless, the infinite, that vast extension forces upon our minds. In like manner, the immeasurable in minuteness is an inevitable mental sequence from the facts and phenomena revealed to us by a study of the minute in nature. The practical divisibility of matter disclosed by modern physics may well arrest and astonish us. But biology, the science which investigates the phenomena of all living things, is in this matter no whit behind. The most universally diffused organism in nature, the least in size with which we are definitely acquainted, is so small that fifty millions of them could lie together in the one-hundredth of an inch square. Yet these definite living things have the power of locomotion, of ingestion, of assimilation, of excretion, and of enormous multiplication, and the material of which the inconceivably minute living speck is made is a highly complex chemical compound. We dare not attempt a conception of the minuteness of the ultimate atoms that compose the several simple elements that thus mysteriously combine to form the complex substance and properties of this least and lowliest living thing. But if we could even measure these, as a mental necessity, we are urged indefinitely on to a minuteness without conceivable limit, in effect, a minuteness that is beyond all finite measure or conception. So that, as modern physics and optics have enabled us not to conceive merely, but to actually realize, the vastness of spatial extension, side by side with subtile tenuity and extreme divisibility of matter, so the labor, enthusiasm, and perseverance of thirty years, stimulated by the insight of a rare and master mind, and aided by lenses of steadily advancing perfection, have enabled the student of life-forms not simply to become possessed of an inconceivably broader, deeper, and truer knowledge of the great world of visible life, of which he himself is a factor, but also to open up and penetrate into a world of minute living things so ultimately little that we cannot adequately conceive them, which are, nevertheless, perfect in their adaptations and wonderful in their histories. These organisms, while they are the least, are also the lowliest in nature, and are to our present capacity totally devoid of what is known as organic structure, even when scrutinized with our most powerful and perfect lenses. Now these organisms lie on the very verge and margin of the vast area of what we know as living. They possess the essential properties of life, but in their most initial state. And their numberless billions, springing every moment into existence wherever putrescence appeared, led to the question, How do they originate? Do they spring up de novo from the highest point on the area of not-life, which they touch? Are they, in short, the direct product of some yet uncorrelated force in nature, changing the dead, the unorganized, the not-living, into definite forms of life? Now this is a profound question, and that it is a difficult one there can be no doubt. But that it is a question for our laboratories is certain. And after careful and prolonged experiment and research the legitimate question to be asked is, Do we find that, in our laboratories and in the observed processes of nature now, the not-living can be, without the intervention of living things, changed into that which lives?

To that question the vast majority of practical biologists answer without hesitancy, No, we have no facts to justify such a conclusion. Prof. Huxley shall represent them. He says: "The properties of living matter distinguish it absolutely from all other kinds of things;" and, he continues, "the present state of our knowledge furnishes us with no link between the living and the not-living." Now let us carefully remember that the great doctrine of Charles Darwin has furnished biology with a magnificent generalization; one indeed which stands upon so broad a basis that great masses of detail and many needful interlocking facts are, of necessity, relegated to the quiet workers of the present and the earnest laborers of the years to come. But it is a doctrine which cannot be shaken. The constant and universal action of variation, the struggle for existence, and the "survival of the fittest," few who are competent to grasp will have the temerity to doubt. And to many, that lies within it as a doctrine, and forms the fibre of its fabric, is the existence of a continuity, an unbroken stream of unity running from the base to the apex of the entire organic series. The plant and the animal, the lowliest organized and the most complex, the minutest and the largest, are related to each other so as to constitute one majestic organic whole. Now to this splendid continuity practical biology presents no adverse fact. All our most recent and most accurate knowledge confirms it. But the question is, Does this continuity terminate now in the living series, and is there then a break—a sharp, clear discontinuity, and beyond, another realm immeasurably less endowed, known as the realm of not-life? or Does what has been taken for the clear-cut boundary of the vital area, when more deeply searched, reveal the presence of a force at present unknown, which changes not-living into the living, and thus makes all nature an unbroken sequence and a continuous whole? That this is a great question, a question involving large issues, will be seen by all who have familiarized themselves with the thought and fact of our times. But we must treat it purely as a question of science; it is not a question of how life first appeared upon the earth, it is only a question of whether there is any natural force now at work building not-living matter into living forms. Nor have we to determine whether or not, in the indefinite past, the not-vital elements on the earth, at some point of their highest activity, were endowed with, or became possessed of, the properties of life.



On that subject there is no doubt. The elements that compose protoplasm—the physical basis of all living things—are the familiar elements of the world without life. The mystery of life is not in the elements that compose the vital stuff. We know them all, we know their properties. The mystery consists solely in how these elements can be so combined as to acquire the transcendent properties of life. Moreover, to the investigator it is not a question of by what means matter dead—without the shimmer of a vital quality—became either slowly or suddenly possessed of the properties of life. Enough for us to know that whatever the power that wrought the change, that power was competent, as the issue proves. But that which calm and patient research has to determine is whether matter demonstrably not living can be, without the aid of organisms already living, endowed with the properties of life. Judged of hastily, and apart from the facts, it may appear to some minds that an origin of life from not-life, by sheer physical law, would be a great philosophical gain, an indefinitely strong support of the doctrine of evolution. If this were so, and, indeed, so far as it is believed to be so, it would speak and does speak volumes in favor of the spirit of science pervading our age. For although the vast majority of biologists in Europe and America accept the doctrine of evolution, they are almost unanimous in their refusal to accept as in any sense competent the reputed evidence of "spontaneous generation;" which demonstrates, at least, that what is sought by our leaders in science is not the mere support of hypotheses, cherished though they may be, but the truth, the uncolored truth, from nature. But it must be remembered that the present existence of what has been called "spontaneous generation," the origin of life de novo to-day, by physical law, is by no means required by the doctrine of evolution. Prof. Huxley, for example, says: "If all living beings have been evolved from pre-existing forms of life, it is enough that a single particle of protoplasm should once have appeared upon the globe, as the result of no matter what agency; any further independent formation of protoplasm would be sheer waste." And why? we may ask. Because one of the most marvelous and unique properties of protoplasm, and the living forms built out of it, is the power to multiply indefinitely and for ever! What need, then, of spontaneous generation? It is certainly true that evidence has been adduced purporting to support, if not establish, the origin in dead matter of the least and lowest forms of life. But it evinces no prejudice to say that it is inefficient. For a moment study the facts. The organisms which were used to test the point at issue were those known as septic. The vast majority of these are inexpressibly minute. The smallest of them, indeed, is so small that, as I have said, fifty millions of them, if laid in order, would only fill the one-hundredth part of a cubic inch. Many are relatively larger, but all are supremely minute. Now, these organisms are universally present in enormous numbers, and ever rapidly increasing in all moist putrefactions over the surface of the globe.

Take an illustration prepared for the purpose, and taken direct from nature. A vessel of pure drinking water was taken during the month of July at a temperature of 65 deg. F., and into it was dropped a few shreds of fish muscle and brain. It was left uncovered for twelve hours; at the end of that time a small blunt rod was inserted in the now somewhat opalescent water, and a minute drop taken out and properly placed on the microscope, and, with a lens just competent to reveal the minutest objects, examined. The field of view presented is seen in Fig. 1, A. But—with the exception of the dense masses which are known as zoogloea or bacteria, fused together in living glue—the whole field was teeming with action; each minute organism gyrating in its own path, and darting at every visible point. The same fluid was now left for sixteen hours, and once more a minute drop was taken and examined with the same lens as before. The field presented to the eye is depicted in Fig. 1, B, where it is visible that while the original organism persists yet a new organism has arisen in and invaded the fluid. It is a relatively long and beautiful spiral form, and now the movement in the field is entrancing. The original organism darts with its vigor and grace, and rebounds in all directions. But the spiral forms revolving on their axes glide like a flight of swallows over the ample area of their little sea. Ten hours more elapsed and, without change of circumstances, another drop was taken from the now palpably putrescent fluid. The result of examination is given in Fig. 1, C, where it will be seen that the first organism is still abundant, the spiral organism is still present and active, but a new and oval form, not a bacterium, but a monad, has appeared. And now the intensity of action and beauty of movement throughout the field utterly defy description, gyrating, darting, spinning, wheeling, rebounding, with the swiftness of the grayling and the beauty of the bird. Finally, at the end of another eight to sixteen hours, a final "dip" was taken from the fluid, and under the same lens it presented as a field what is seen in Fig. 1, D, where the largest of the putrefactive organisms has appeared and has even more intense and more varied movements than the others. Now the question before us is, "How did these organisms arise?" The water was pure; they were not discoverable in the fresh muscle of fish. Yet in a dozen hours the vessel of water is peopled with hosts of individual forms which no mathematics could number! How did they arise? From universally diffused eggs, or from the direct physical change of dead matter into living forms? Twelve years ago the life-histories of these forms were unknown. We did not know biologically how they developed. And yet with this great deficiency it was considered by some that their mode of origin could be determined by heat experiments on the adult forms. Roughly, the method was this: It was assumed that nothing vital could resist the boiling point of water. Fluids, then, containing full-grown organisms in enormous multitudes, chiefly bacteria, were placed in flasks, and boiled for from five to ten minutes. While they were boiling the necks of the flasks was hermetically closed; and the flask was allowed to remain unopened for various periods. The reasoning was: "Boiling has killed all forms of vitality in the flask; by the hermetical sealing nothing living can gain subsequent access to the fluid; therefore, if living organisms do appear when the flask is opened, they must have arisen in the dead matter de novo by spontaneous generation, but if they do never so arise, the probability is that they originate in spores or eggs."

Now it must be observed concerning this method of inquiry that it could never be final; it is incompetent by deficiency. Its results could never be exhaustive until the life-histories of the organisms involved were known. And further, although it is a legitimate method of research for partial results, and was of necessity employed, yet it requires precise and accurate manipulation. A thousand possible errors surround it. It can only yield scientific results in the hands of a master in physical experiment. And we find that when it has secured the requisite skill, as in the hands of Prof. Tyndall, for example, the result has been the irresistible deduction that living things have never been seen to originate in not-living matter. Then the ground is cleared for the strictly biological inquiry, How do they originate? To answer that question we must study the life histories of the minutest forms with the same continuity and thoroughness with which we study the development of a crayfish or a butterfly. The difficulty in the way of this is the extreme minuteness of the organisms. We require powerful and perfect lenses for the work. Happily during the last fifteen years the improvement in the structure of the most powerful lenses has been great indeed. Prior to this time there were English lenses that amplified enormously. But an enlargement of the image of an object avails nothing, if there be no concurrent disclosure of detail. Little is gained by expanding the image of an object from the ten-thousandth of an inch to an inch, if there be not an equivalent revelation of hidden details. It is in this revealing quality, which I shall call magnification as distinct from amplification, that our recent lenses so brilliantly excel. It is not easy to convey to those unfamiliar with objects of extreme minuteness a correct idea of what this power is. But at the risk of extreme simplicity, and to make the higher reaches of my subject intelligible to all, I would fain make this plain.

But to do so I must begin with familiar objects, objects used solely to convey good relative ideas of minute dimension. I begin with small objects with the actual size of which you are familiar. All of us have taken a naked eye view of the sting of the wasp or honey bee; we have a due conception of its size. This is the scabbard or sheath which the naked eye sees.[3] Within this are two blades terminating in barbed points. The point of the scabbard more highly magnified is presented, showing the inclosed barbs. One of the barbs, looked at on the barbed edge, is also seen. Now these two barbed stings are tubes with an opening in the end of the barb. Each is connected with the tube of the sac, C. This Is a reservoir of poison, and D is the gland by which it is secreted. Now I present this to you, not for its own sake, but simply for the comparison, a comparison which struck the earliest microscopists. Here is the scabbard carefully rendered. One of the stings is protruded below its point, as in the act of stinging; the other is free to show its form. Now the actual length of this scabbard in nature was the one-thirtieth of an inch. I have taken the point, C, of a fine cambric sewing needle, and broken it off to slightly less than the one-thirtieth of an inch, and magnified it as the sting is magnified. Now here we obtain an instance of what I mean by magnification. The needle point is not merely bigger, unsuspected details start into view. The sting is not simply enlarged, but all its structure is revealed. Nor can we fail to note that the finish of art differs from that of nature. The homogeneous gloss of the needle disappears under the fierce scrutiny of the lens, and its delicate point becomes furrowed and riven. But Nature's finish reveals no flaw, it remains perfect to the last.

[Footnote 3: A magnified image of the bee's sting was projected on the screen.]

We may readily amplify this. The butterflies and moths of our native lands we all know; most of us have seen their minute eggs. Many are quite visible to the unaided eye; others are extremely minute. A gives the egg of the small white butterfly;[4] B, that of the small tortoiseshell; C, that of the waved umber moth; D, that of the thorn moth; E, that of the shark moth; at F we have the delicate egg of the small emerald butterfly, and at G an American skipper; and finally, at H, the egg of a moth known as mania maura. In all this you see a delicacy of symmetry, structure, and carving, not accessible to the eye, but clearly unfolded. We may, from our general knowledge, form a correct notion of the average relation in size existing between butterflies and their eggs; so that we can compare. Now there is a group of extremely minute, insect-like forms that are the parasites of birds. Many of them are just plainly visible to the naked eye, others are too minute to be clearly seen, and others yet again wholly elude the unaided sight. The epizoa generally lodge themselves in various parts of the plumage of birds; and almost every group of birds becomes the host of some specific or varietal form with distinct adaptations. There is here seen a parasite that secretes itself in the inner feathers of the peacock, this is a form that attacks the jay, and here is one that secretes itself beneath the plumage of the partridge.

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