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THE CHEMICAL

VOL. XXXII. No. 861.

Experiments V. and VI.-Upon replacing the broad NEWS. electrodes by others only half an inch wide very different

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THE author first briefly traces the history of electrolysis from the discovery by Nicholson and Carlisle of the decomposition of water by the pile, down to the Bakerian Lecture of Sir H. Davy in 1807.

Grotthus contended the in the elementary combinations of the pile of as in a magnet, there is polarity, it would establish a l ha like condition in the elements of water. To this Faraday added the necessary idea of the revolution of the molecules of the electrolyte.

If the condition of an electrolyte just prior to, and in the act of, decomposition be in accordance with these views of Grotthus and Faraday, an electrolyte may be regarded as a dielectric whose molecules are possessed of the power of mutually exchanging their constituents during discharge. This view, jointly with some supposed points of resemblance between magnetic and electrolytic substances, led to the experiments detailed in the communication.

results were obtained. The action was a minimum at about the middle of the line, and rose towards each end, but being about twice as great at the positive as at the negative electrode. With the exception of this difference at the two electrodes these experiments are explicable upon the hypothesis of Grotthus. The influence of the direction in which the strip is inserted is shown. When placed across the line joining the electrodes it has no action, nor does it interfere with the action of the other strips.

Experiment VII.-The amount of action is shown to increase rapidly with the length of the strip.

Experiment VIII.-Pieces of glass, charcoal, and platinum were supported in solution of copper sulphate. On connecting the copper electrodes with the battery it became evident that the platinum gave the greatest action, This illustrates the charcoal a little, and the glass none. the effect of conductivity.

Experiment IX.-The influence of the chemical activity These numbers were of the strips was determined. obtained for the relative activity :

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Experiment X.-By the use of strips distributed throughout the liquid, the lines of discharge between electrodes of small dimensions are investigated, and the electric influence is shown to spread out from the electrodes in a manner much resembling the spread of the magnetic influence in the magnetic field of two dissimilar poles.

Experiment I.-A piece of thin copper wire about an inch long was suspended lengthwise, by a piece of cotton, between the copper electrodes (distant about 4 inches) of a Grove's battery, and immersed in a 5 per cent solution of potassium chloride. Gas was at once given off from the end of the wire facing the positive pole, and after the lapse of a few minutes the end facing the negative battery NOTES ON THE ALLEGED REPLACEMENT O pole was found corroded.

Experiment II.-Four thin silver strips were supported lengthwise in a line between copper electrodes in a 5 per cent solution of copper sulphate mixed with a little potassium chloride. On making contact, silver chloride immediately formed upon the ends of the strips facing the negative pole, and descended in clouds, being apparently attracted towards the battery poles. Copper was deposited upon the other ends.

The preceding experiments demonstrate that an insulated conductor immersed in an electrolysing fluid may become endowed with the power of doing work exactly similar to that done by the battery poles; may, because, as is subsequently shown, the working power of the insulated conductors depends upon its length, position in the fluid, and conductivity, as well as chemical activity.

The action is easily explicable upon the supposition that the battery electrodes charged with electricity polarise the insulated conductor through the electrolyte, just as static electricity polarises an insulated conductor in air, the difference between the two phenomena being that a high electric tension is necessary to effect the depolarisation of the particles of air by discharge, which, of course is unaccompanied by decomposition; whereas only a very low electric tension is required to effect the depolarisation of an electrolyte, which, on the contrary, is always accompanied by decomposition.

Experiments III. and IV.-A series of twelve strips, half-inch by quarter-inch, were supported in line as in the last experiment, the electrodes reaching all the way across the trough (which was 12 inches long), and being oneeighth inch distant from the end strips. A determination of the amount of copper on each of the strips showed that the amount of decomposition was equal throughout the length.

1876.

Abstract of a Paper read before the Royal Society, February 17,

ELECTRO-POSITIVE BY ELECTRO-NEGATIVE

METALS IN A VOLTAIC CELL.

By WILLIAM SKEY,

Analyst to the Geological Survey of New Zealand.

IN a paper by Prof. Gladstone, Ph.D., F.R.S., and Mr. Alfred Tribe, which was read before the Royal Society on November 25th, 1875, it is asserted that when zinc and platinum are connected voltaically in a solution of chloride of potassium, "potassium is set free in some form against the platinum, manifesting itself by the presence of free alkali and hydrogen gas ;" and the authors of this paper, upon the supposition above stated, and others based in a similar way, argue for the replacement of electro-positive by electro-negative metals under conditions quite contrary to those we have hitherto held to be necessary, explaining this "reversion," as they term it, by assuming that some force superior to that of chemical affinity operates for its production, and which is "called into existence by contact."

I will not here discuss the propriety of resurrecting the "contact theory," which I thought Prof. Faraday had long since disposed of; but I would like to make a few observations upon two statements which appear in this paper.

In the first place, as far as I can understand from the abstract of it given in Nature, it is by no means clear that "potassium is set free" in the experiment described. The alkaline reaction upon which this theory of metallic reduction is based may in reality be due to a cause quite different from that of such a reduction. For instance, an alkaline reaction can be readily obtained under circumstances which are similar to those related here, except that "contact" in a voltaic arrangement with dissimilar metals is avoided, and under which it appears impossible that any metallic reduction takes place. Thus an aqueous solution

*

of chloride of potassium, placed for a short time with | tain that these metals initiate or facilitate this attack by amalgamated zinc, or for a longer time with zinc itself, reason of the oxygen condensed (chemically) upon their even at common temperatures, becomes very alkaline. surfaces, and, further, as gold will also certainly possess Even pure silver in a solution of this salt soon passes it to a similar though a faster condensing power over this gas, this condition. The containing vessels in my experiments we must consider the possibility of part of the mercurous for this were agate. deposits produced in all these experiments being due indirectly to the metals used in them for the negative or receiving pole. In such experiments we may safely assume that a portion of the hydrochloric acid present has been decomposed, the oxygen condensed upon the negative element oxidising its hydrogen, while the chlorine of this compound attacks the mercury. It is, in fact, a case where both poles conspire to give an effect (that is, the decomposition of hydrochloric acid) not producible by either pole separately; and it may, as now known, throw a light upon the mode in which chemical action is so frequently facilitated, or even at times initiated, by touching the positive metal with a metal negative to it in the solution we may be operating with.

This change in the character of these solutions is hardly wrought by metallic reduction, but rather, in the first case, by decomposition of water and the formation of ammonia (by the interaction of the nascent hydrogen thus liberated upon nitrogen present), assisted perhaps by the formation of oxide of zinc by atmospheric oxidation, resulting finally in the formation of an oxychloride of this metal through substitution. In the second case, that of silver, we have its direct oxidation by the free oxygen present and the reaction of this oxide upon the salt present, chloride of silver and caustic potash resulting, to which last compound, of course, that alkalinity is induced which we observe.

In the case of zinc, it may be that the actions which result in alkalinity of the saline liquid surrounding it may not be so simple as I here suppose, for the investigation seems to be required ere we can fully explain them; but still the results I have here described, and several others I could cite of an analogous nature, certainly tend to show that the conception of metallic "replacement," as given in this paper of Prof. Gladstone's, is as yet scarcely a tenable one, or at least that it requires for adequate support considerably more evidence than has yet been tendered in its behalf.

With regard now to the next statement I have here to remark upon, viz., that mercury and gold in conjunction would decompose mercuric chloride, with deposition not only of lower chloride but also of metallic mercury, I will take leave to suggest, in explanation of this, the possibility of floating dust or other impurities, or even light itself, interfering with what should be the legitimate results of the experiment described. In support of this view I found that mercury, which for utmost purity I had electro-deposited from its potassic cyanide upon platinum, gave a deposit upon gold of mercurous chloride only, in presence of mercuric chloride when kept in the dark and away from dust.

I may state here that the detection of either mercurous chloride or mercury seems greatly facilitated by using platinum in place of gold for the receiving-plate, as this metal (platinum) loses greatly in lustre by minute traces upon it of such chloride, and any mercury present is easily rubbed off upon an angle of gold, and thus readily identified.

Using this modification of Prof. Gladstone's apparatus, I was only able to get, even in sixteen hours, a deposit of mercurous chloride which was so exceedingly thin as not to perceptibly impair the lustre of the platinum upon which it had formed: its presence, in fact, would not readily be detected except by the slight darkening of this platinum in caustic potash. By the addition of hydrochloric acid, however, to the mercuric chloride, thicker deposits of this kind were obtained, but none of mercury. The deposit of this mercurous salt though, even alone, under the circumstances described by these investigators, appears to be a very suggestive phenomenon, and this because it appears inexplicable as at first viewed. I can only attribute this deposit to the action of a free acid or of free acids upon the mercury; a minute quantity of nitric or nitrous compounds dissolved in the solution used (taken from the air) would certainly be competent to act upon mercury to the extent required for producing mercurous films such as I have obtained.

However, in regard to this deposit, and that chemical action upon mercury by some free acid which I consider necessary for its production, I find that hydrochloric acid, even, readily attacks mercury when the metal is paired voltaically with platinum or graphite: now, as it is cer"Oxidation of Silver and Platinum by Oxygen in Presence of Water." Trans. of N. Z. Institute, vol, viii.

It appears to me that this matter is well worth investi. gating.

REPORT
ON THE

DEVELOPMENT OF THE CHEMICAL ARTS
DURING THE LAST TEN YEARS.*
By Dr. A. W. HOFMANN.

Progress in the Artificial Production of Cold and Ice.
By Dr. H. MEIDINGER.

(Continued from p. 194.)

ACCORDING to experience hitherto, the air machines seem better adapted for the immediate application of cold air than for concentrating and storing up cold in the form of ice, in which respect they fall too far short of the ammonia machines. They may probably be found serviceable in breweries for cooling cellars. Motive power is always to be found in such establishments with which the air-pumps can be readily connected. The introduction of cold air into the cellars secures further the advantage that they are kept very dry by means of this air, which during its compression and expansion has been to a great extent deprived of its moisture, and hence no mould is formed. Cooling with ice, on the other hand, saturates the air of cellars with moisture, and keeps it stagnant. The whole process can be carried on in breweries at a relatively small expense, as in such establishments much heat and especially much hot water is required, and thus both the escaping steam and the hot water obtained by cooling the compressed air can be utilised. An air machine supplied by Mehrlich and Co. to Hildebrand's brewery at Pfungstadt, near Darmstadt, has given for a year very satisfactory results. The principle of the air machine seems also especially adapted for ventilation where it is desirable to combine reduction of temperature with renewal of the air, as in hospitals, public rooms, and steamships. Here a trifling expansion and a small degree of cold would suffice, and hence the working cost would appear relatively low. We may look forward with interest to the further development of this subject.

We have still to make mention of a more extended theoretical investigation which Lindet has given to the public on the " withdrawal of heat at low temperatures by mechanical agencies." The main result which he has arrived at in the way of calculation-which, however, appears at once on an attentive physical consideration of the changes that take place-is that for the economical working of ice machines the temperature of the body used as a medium during expansion must not be lower, and during compression not higher, than is absolutely necessary.

"Berichte über die Entwickelung der Chemischen Industrie Während des Letzten Jahrzenends."

+ Linde, Bayer. Industrie u. Gewerbeblatt, July, Nov., and Dec., 1870,

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This condition has hitherto been frequently overlooked, and ignored. Whilst it has frequently been said, in explaining the merits of an ice machine that it works at such or such low temperatures, the very opposite should be the case; it should be shown that the machine produces ice without requiring a temperature far below the freezing-point of water. The above-mentioned praise is merely a certain proof that the machine consumes much power needlessly. Certainly in this case the machine may be smaller and the first outlay easier, but this advantage generally vanishes in comparison with the drawback of increased working charges. Linde proves by calculation that in a theoretically perfect machine, which produces ice at -3° from water at +10° C., I kilo. of coal should yield 100 kilos. of ice. He combines also with his theoretical researches a critique on all ice-machines hitherto constructed. All makers of such machines should make themselves thoroughly masters of the principles here developed, which would keep them from going astray.

In 1873* J. Armengaud communicated certain theoretical speculations on air-machines to the French Academy, which, however, contained nothing essentially novel. He lays especial stress upon the importance of cooling the air during compression by means of water. The difficulty of effecting this by means of water injected in the moment of compression he overcame by introducing into the air, as drawn in, water, by means of Gifford's injector, probably as fine spray. According to his experiments it is most advantageous to work with a degree of expansion 2, in which case the power exerted, in proportion to the cold produced, is only half as great when the refrigeration is carried on during compression as if executed previously.

Nature of Artificial Ice.-Ice rapidly produced, at a very low temperature, is quite opaque and of a milky white. From this appearance-so different from the vitreous, transparent aspect of natural ice the strangest conclusions have been drawn as to its behaviour. Sometimes it was assumed to be more and sometimes less permanent, sometimes to have more and sometimes less cooling power than natural ice. The truth is that artificial and natural ice differ merely in appearance. A piece of the former just taken out of the machine is of course colder than a block from the ice-cellar, and consequently melts rather more slowly on exposure to the air. Equally large pieces of natural and of artificial ice, at the same temperature, melt with equal speed under similar external conditions, and exert equal refrigeratory powers. (To be continued.)

RESEARCHES ON THE SOLID CARBON
COMPOUNDS IN METEORITES.+
By J. LAWRENCE SMITH, Louisville, Ky.
(Concluded from page 197).

The Alais Meteorite.

Two grammes of this meteorite were pulverised finely and treated with boiling water, which dissolved out a small amount of matter that has been studied by others, and which it is not my object to recur to here.

The powder was then dried and treated with pure ether in the same manner as the graphite from the Sevier iron, and the ether allowed to evaporate slowly at a moderate temperature, when the sides of the vessel became covered with acicular crystals, mixed with a few rhomboidal crystals. The residue had a peculiar odour, similar to that of the ether extract from the graphite of the Sevier iron, which odour it nearly lost in the same way, after several days exposure to the air. The form and appear

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ance of the crystals are the same as those obtained from that graphite; and a portion of the crystals detached aad heated in a small tube gave the same character or reaction.

These crystals have already been studied by Prof. Roscoe, of Manchester, as carefully as could be done with the minute quantity at his disposal. My examination is perfectly in accordance with his, and there is no doubt that this product and that from the graphite must be of the same nature.

We must not forget to mention that Prof. Wöhler was the first to call attention to the hydrocarbon in these black meteorites when examining the one which fell at Kaba. Orgueil Meteorite.

This meteorite is one of the most interesting of all the known carbonaceous meteorites, and there are one or two points connected with it that do not appropriately belong to this paper of which I will furnish a note before long. Through the liberality of Prof. Daubrée, and the Administration of Garden of Plants, I have been furnished with the material on which my investigations have been made. This meteorite has, in most respects, been thoroughly examined by M. Clcez, and by M. Pisani, and their results given in the Comptes Rendus for 1864. The former chemist examined the carbonaceous matter as a whole, considering it to resemble humus; and this, on drying at 110°, gave him :-Carbon, 63'45; hydrogen, 5'98; oxygen, 30'75.

I have, as yet, done little toward the re-examination of this substance, which represents from 4 to 6 per cent of the entire meteorite, my examinations being made principally for those crystalline products soluble in ether and bisulphide of carbon, of which I have found about onehalf per cent in the meteorite.

The powdered meteorite was first treated with water and heated over a water-bath, and everything soluble in that menstruum thoroughly washed out. The soluble portion dried at 100° C., represents 8.65 per cent of the mass. After carefully drying the insoluble portion at 100° C., it was treated with ether in the same manner as the meteoric graphite. The ether was used in large excess, and allowed to remain for ten or twelve hours in contact with the material; the ether was filtered off, and the residue on the filter well washed with ether. The etherial solution was evaporated slowly, when the same acicular crystals made their appearance as in the case of the graphite, and numerous rhomboidal crystals were deposited in the bottom of the beaker. These appeared to be identical with those from the graphite. The action of heat on these crystals is the same as on those from the Sevier graphite.

The powdered meteorite exhausted by the water and ether was next treated by the bisulphite of carbon, when an additional quantity of soluble matter was obtained. On evaporating the bisulphite of carbon, a yellow mass remained having the aspect of sulphur. This, when heated, gave evidence of being sulphur mixed with some carbon compound, and to all appearance it was just like the substance obtained by similar treatment of the meteoric graphite.

The crystals in the upper part of the vessel from which the ether was evaporated being detached by scraping the sides of the vessel with a horn spatula, some bisulphide of carbon was poured upon the portions remaining attached to the vessel by which it was dissolved, and the bisulphide of carbon was subsequently evaporated, when a residue was left consisting of a yellow solid surrounded by a dark brown semi-solid mass in minute quantity. This last is evidently a carbon combination not contaminated with sulphur, while the yellow mass is sulphur containing a small portion of the carbon compound.

I was enabled to obtain over 400 milligrms. of these mixtures from about 50 grms. of the meteorite, much the larger portion being sulphur. A few attempts were made to separate the sulphur from the carbon compound, but

unsuccessfully; and I soon saw that by continuing my, efforts, I should exhaust the small supply of material without reaching any useful result. So it was thought better to save what was left of the material as a specimen of it.

The other carbon meteorites I have not yet examined with regard to the points embraced in this report, but I hope to obtain sufficient material before long to allow of this being done, though I do not anticipate any different results from those that have been examined.

The Nature of the Hydrocarbon found in the Meteoric Graphite and Carbonaceous Meteorites.

That this substance belongs to the meteorites at the time of their fall there can be no doubt; for in the carbonaceous meteorites there is nothing to enable us to account for its formation in the cabinets in which they have been placed after their fall: and in the case of the graphite nodules they were encased in the interior of an iron mass over 20 c.m. in diameter; and, furthermore, the powder operated with was taken from the interior of a compact nodule of graphite.

I have been strongly inclined to consider this as a hydrocarbon containing combined sulphur forming a sulphydrocarbon. In the absence of chemical evidence sustaining this view, I lay some stress on the peculiar odour of the ether extract, strengthened by a most singular property of the watery extract from the Orgueil meteorite, of which I will make a short statement, reserving for some future occasion any additional remarks. If a small quantity of the powdered Orgueil meteorite, say 2 grms., be treated with water and heated for a short time over a water-bath, no peculiar odour will be observed however carefully examined. Throw this on a filter and wash with water, then evaporate the filtrate to dryness over a water-bath, and during this time no odour will be observed; allow the residue to cool, and still there is no odour; but now throw upon the residue a little water, say to I c.c., move the capsule around to dissolve the mass, and then on bringing it near to the nose, a marked alliaceous odour will be perceived, sometimes so strong as to be disagreeable, reminding one of the odour of the oil of assafoetida. That it is produced by a sulphur compound chemists will be apt to admit, perhaps a minute quantity of sulphur compound, not unlike the sulphydrate of ethylene, C4H6S4, and the needle-shaped crystals may not be far removed from the solid quintisulphide of ethylene, C4H6S5, corresponding to sulphur 75:00, carbon 2000, hydrogen 5:00. The crystals I scraped from the sides of the beaker-at the upper part-on which the ether solution of the Orgueil meteorite was evaporated to dryness, gave:-Sulphur, 7965; carbon, 15'00; hydrogen, 3'00.

In the above analysis the amount of sulphur is well determined; but the examination for carbon and hydrogen was made upon so small a quantity that the results cannot be relied upon as very correct.

Roscoe burnt in dry oxygen o'008 grm. of the residue from the Alais meteorite, and obtained oo10 grm. of sulphurous acid, o'008 grm. of carbonic acid, and 0·003 grm. of water, making sulphur 125 parts, carbon 54 parts, hydrogen 10.

As the above analysis was made with only 8 milligrms., of course the results can be considered only as an approximation; but nevertheless, until we get better they must serve as our only guides.

I have not said anything about the gaseous carbon compounds found in meteorites, as these form a separate study from what is designed in this paper, and besides, Profs. Graham, Mallet, Wright, and others have already studied their nature. Profs. Wright and Mallet are still engaged in this line of investigation.

Conclusions.

These, then, are some of the results of my experiments on the carbon of meteorites, and they are of great interest and importance. That we should find in the graphitic

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concretions from the interior of a solid mass of iron such substances as free sulphur and a hydrocarbon, simple, or combined with sulphur, having a marked odour, was certainly not to be expected, especially as we are almost forced to believe that the iron containing it must have been at some period in a state of fusion.*

The graphite nodules themselves are grand chemical and physical puzzles, as well as all the nodular concretions in meteoric irons; that they have resulted from a process of segregation is self-evident, but how marvellous the completeness of this segregation, for if we analyse the iron, even within 2 or 3 m.m. of the concretions, only traces of the characteristic constituents of the nodules are here found. Then, again, in the case of the trolite concretions, this sulphide has been separated from the mass of iron, and a phosphide of iron and nickel has been concreting along with it; and yet there seems to be that incompatibility between these two minerals so that they could not commingle, but the phosphuret is thrust, as it were, to the exterior of the nodule, forming a thin covering to the sulphide, like the skin of an orange over the internal pulp.

Again, the graphitic concretions bear no resemblance to the scaly graphite found in the slag of iron furnaces and between the crystals of cast-iron, either in structure or appearance; the fractured surface is more like that of the Borrowdale graphite, but the oxidising action of the nitric acid and potash chlorate on this last differs somewhat from the action on the meteoric graphite. Many and varied have been the hypotheses formed in my mind to account for the formation and accumulation of this graphite, but I must admit that I have been forced at last to abandon them all, as none covers all the facts of the case. In appearance this graphite is more like the amorphous carbon that is separated from cast-iron, but the oxidising action of the nitric acid and chlorate of potash at once points out their great difference as seen by Berthelot's experiments ;t and although it differs in appearance from the scaly graphite of iron, the oxidation of the two are very similar. I am more inclined to adopt the suggestion of Berthelot, that it may be formed by the reaction of bisulphide of carbon upon incandescent iron, as this reaction is known to give rise to an amorphous graphite analogous to the one under consideration, and its association with sulphide of iron would lend some support to this hypothesis; and still further the presence of free sulphur and a carbon compound, either a hydrocarbon or sulphydrocarbon, points also in that direction for a solution.

It is very clear from the present accumulated knowledge of the geological occurrences of graphite that we must abandon all attempt to account for its formation by any one series of reactions on the interior of our globe; for it is to be found in basaltic rocks, in the older crystalline rocks, and through all the series of rocks up to the recent tertiary formations, and when we add to this the laboratory experiments of Berthelot that I have so frequently quoted, this view of the subject is strengthened. But on this point I may have something more to say in a paper on the Ovifak iron, and the graphite in the basalt in which this iron is found.

The carbon from the black meteorites, as the Orgueil, Alais, &c., I consider as having a similar origin to that found in the irons; for I have proved that they both contain similar crystalline products soluble in ether and sulphide of carbon, and while the carbonaceous matter reacts differently when treated with nitric acid and potash chlorate, this may arise from the difference of conditions under which the reaction took place that gave rise to it.

That the carbonaceous matter in the black meteorites is

* In an article recently published by Dr. Mohr (Annalen der Chem. und Pharm., Dec., 1875, p. 257), he advances the theory that meteoric iron and meteoric stones have been formed by the agency of water; cing to cover all the facts in connection with meteorites. his arguments are interesting, but far from being sufficiently convin

+ Annales de Chem. et de Physique, Fourth Series, T. xix., p. 425.

to be regarded as a kind of humus arising from organised | matter is contrary to all we know about humus. For if we examine the mineral constituents of these meteorites we find them to be a granular mass, with particles more or less impalpable, composed essentially of olivine and pyroxene, a most unpromising soil for so luxuriant a growth of vegetation as must have occurred to produce so abundant a percentage of carbonaceous matter as that found in the Orgueil meteorite. The action of caustic potash upon it is very different from the action of that alkali uron what is commonly called humus (although we must bear in mind that humus is not a well-defined substance, it being commonly regarded as vegetable matter that has not undergone complete decomposition into water and carbon, but by imperfect oxidation is converted into a varied mixture of carbon and certain organic compounds rich in carbon, some of them soluble in caustic alkalies). After the powdered Orgueil meteorite has been exhausted by water, ether, and sulphide of carbon, caustic potash or soda dissolves but an exceedingly minute trace of the carbonaceous matter, and even that trace may be a little hydrocarbon not extracted from the mass by the ether and sulphide of carbon. If a portion of the same be dried at 110° C., and then heated in a closed tube, water will not be given off until the temperature is elevated considerably. If the temperature be further increased, only a very slight odour is apparent; and this is another marked difference between it and humus. If heated on platinum foil the carbonaceous matter burns off very readily with little or no odour, leaving an abundant residue. According to my experiments this combustible matter amounts to about 45 per cent of the entire meteorite.

It is not at all improbable that the carbonaceous matter of the black meteorites approaches in character the socalled hydrated carbon first pointed out by M. Eggertz, but so clearly defined by MM. Schutzenberger and Bourgeois in a communication made to the Chemical Society of Paris, in April, 1875, which was obtained from white cast-iron by dissolving away the iron. But it is a question, in my mind, whether the carbon combination thus obtained from white iron is to be properly considered a hydrated carbon; that is to say, whether we are to consider the H2O as united to the carbon in the same way as it is to metallic oxides to form what are known as hydrated oxides. If, however, it is to be considered as combined in a manner analogous to the H2O, with ethyl to form alcohol, then there may be some plausibility in the hypothesis. For it will be remarked in referring to the actions of this hydrated carbon that it in no way resembles amorphous or ordinary carbon.

It is represented by MM. Schutzenberger and Bourgeois as follows:-C: 3H2O; carbon, 70'95; hydrogen, 3'23; oxygen, 25.80 per cent.

According to M. Cloez the carbonaceous matter of the Orgueil meteorite, after being dried at 110°, was found to be composed of :-Carbon, 63'45; hydrogen, 5'98; oxygen, 30.75; and when we consider that some of this hydrogen belongs to the hydrocarbon now known to exist in that meteorite, the remainder of the hydrogen will approach near the proportion required to form water with the oxygen; and the quantity of carbon that may exist as a hydrate will be slightly diminished.

Attempts were made to separate completely all the mineral matter from the carbon, but I have failed to do so, after using fluorhydric acid alone, and in conjunction with nitric acid, also fluoride of sodium and sulphuric acid with a small amount of water, then treating the residue with 'cold nitric acid. There is no difficulty in getting rid of a great part of it, but in every instance the carbonaceous matter has been altered, however carefully the temperature was managed.

When this matter thus obtained is heated in a closed tube, after being dried at 110° C., it not only furnishes water at about 250° C., but gives out a very strong odour somewhat like that produced from certain bituminous

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coals, at one point resembling the disagreeable odour of an ignited cigar of a very inferior quality of tobacco.* Viewed in the light of these experimental researches, the most reasonable conclusion is that this carbonaceous matter is not in any proper sense either carbon or humus, but a carbon compound analogous to the one just referred Future researches upon the solid compounds, resembling in appearance amorphous carbon, such as hydrographitic oxide, pyrographitic oxide, carbon hydrate, and similar compounds that may yet be discovered, will doubtless throw some light on the true nature of the carbonaceous compound of the black meteorites. So far as our knowledge now extends, its formation and its origin are wrapped in as much obscurity as the origin of the bodies in which it is found.

What we do know is that this carbonaceous matter occurs with the same minerals, viz., olivine and pyroxene, which are the predominating constituent materials of all stony meteorites; also with the nickeliferous iron found in both stony and metallic meteorites; and furthermore, that this carbonaceous matter contains curious crystalline products soluble in ether and sulphide of carbon, which last have been traced in the graphite nodules in the interior of the metallic meteorites. Moreover, in these graphite nodules we have found magnesia, which is so uniformly a constituent of the minerals of the stony meteorites.

So far then as our present knowledge goes, we know of celestial carbon in three conditions, viz.: in the gaseous form as detected by the spectroscope in the attenuated matter of comets; in meteorites in the solid form, impalpable in its nature and diffused in small quantities through pulverulent masses of mineral matter that come to the earth from celestial regions; also in the solid form, but compact and hard, resembling terrestrial graphite, and this is imbedded in metallic matter that comes from regions in space. But while we speak of these as forms of carbon, I think we should be careful in associating it in our minds with the element carbon as we understand it in its pure state whether crystallised or amorphous, for I cannot reconcile the carbon vapour detected in comets as simply that known as pure carbon in the form of an elastic vapour, nor are we to circumscribe ourselves with the notion that this cosmical carbon has an organic origin. The researches embraced in this communication, while in many respects of a novel character, are imperfect from their very nature, both from lack of material for a thorough and complete study, as well as from the present imperfect methods of operating upon the minute quantity of the most interesting of the substances obtained.

I have therefore detailed as carefully as I could all the results as they have developed themselves, hoping that future opportunities may be afforded for continuing them, when new celestial messengers of the carbonaceous type shall visit our globe.

PROCEEDINGS OF SOCIETIES.

CHEMICAL SOCIETY.
Thursday, May 18th, 1876.

Professor ABEL, F.R.S., President, in the Chair.

AFTER the minutes of the previous meeting had been read and confirmed, and the names of the visitors announced, the following names were read for the first time :-Messrs. A. B. Cortis, G. F. Thomson, J. Heron, C. G. Matthews, G. Evans, J. R. Hakewell, and Dr. Otto N. Witt. Messrs. Joseph Davidson, D. Hesketh Richards, and W. J. Han

This odour will be found to belong to the hydrated carbon from cast-iron, when heated in the same way.

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