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in pale yellow micaceous scales insoluble in all reagents. Dried even at ordinary temperatures it agglomerates to brown amorphous tenacious plates in which the primitive structure has disappeared. This character is essential and invariably reappears after all the transformations of the oxyd. Iodhydric acid at 280° C. converts graphitic oxyd into a new substance which Berthelot calls hydrographitic oxyd, containing more hydrogen than its primitive, but brown, amorphous and insoluble in all solvents. The new oxyd is not decomposed with deflagration and intumescence by heat. With potassic chlorate and nitric acid it yields graphitic oxyd with all its original properties. Pyrographitic oxyd from plumbagine is a black, light flaky powder which according to Brodie has the formula €22H202. Nitric acid and potassic chlorate dissolve it almost wholly like the amorphous carbons, but a small quantity of graphitic oxyd is always regenerated.

The graphitic oxyd from graphite of cast-iron presents greenish yellow scales better developed than those from plumbagine and not agglomerating during desiccation. This character which is constant readily distinguishes the oxyd from that obtained from plumbagine. The hydrographitic oxyd from this graphitic oxyd intumesces when submitted to heat, giving off a considerable quantity of iodine. By oxydation it reproduces graphitic oxyd which does not agglutinate by drying. The corresponding pyrographitic oxyd dissolves in a mixture of nitric acid and potassic chlorate in a much more complete manner than that from plumbagine. Some scales of the original graphitic oxyd are however always formed with their distinctive properties.

Graphitic oxyd from electric graphite-carbon points from a large battery is a maroon colored powder which does not agglomerate during desiccation. This character is also constant. The hydrographitic oxyd does not intumesce when heated, and when oxydized reproduces the original oxyd. This form of graphitic oxyd is also decomposed by heat with deflagration but yields a heavy powder which is not flaky. By oxydation the pyrographitic oxyd disappears almost wholly, leaving some grains of graphitic oxyd with its original properties.

All the pyrographitic oxyds when treated with iodhydric acid in solution at 280° C. yield hydrogen containing about 6 per cent of marsh gas, leaving however a considerable quantity of a black carbonaceous residue. The author compares the graphites, amorphous carbons and their derivatives with the hydrates of carbon and ulmic matters, and believes that the varieties of amorphous carbon represent polymeric states of the true carbon which is not yet known in the free or uncondensed form. In studying the different varieties of carbon, Berthelot has arrived at the following results in addition to those related above. Coke recently calcined is entirely dissolved, giving a soluble compound of an intense color. Metallic carbon, deposited from hydrocarbon vapors heated in a porcelain tube, is dissolved with very great difficulty but completely. The same is true for gas-retort carbon and some substances called

artificial graphites. Anthracite, animal charcoal and the carbonaceous matter from the Orgueil meteorite were also completely oxydized, but lamp-black left a trace of graphitic oxyd. The intense heat produced by combustion in oxygen converts a small portion of gas-retort carbon into graphite. Berthelot suggests that it is in this manner that natural graphite has been formed, the amorphous carbon, being more oxydizable at a low temperature, having been gradually dissolved. This view derives some support from the presence of a trace of graphite in lamp black. Electricity also converts amorphous carbon into graphite, the carbon carried over to the negative pole being found to contain a considerable quantity of the latter, while the positive pole contained only a trace. The actual transference of the carbon is not however necessary for the formation of graphite; carbon from sugar softened by the heat from a battery of 600 pairs being found to contain graphite in large proportion. Carbon separated from hydrocarbons by the agency of heat does not contain a trace of graphite, while that which is separated by heat from the sulphid or chlorid of carbon or by chlorine from boron contains a considerable quantity.-Comptes Rendus, lxviii, pp. 183, 259, 331, 392,

445.

W. G.

8. On the direct synthesis of Cyanhydric acid.—BERTHELOT finds that when a stream of sparks from an inductorium is passed for some time through a mixture of acetylene and nitrogen the two gases unite in equal volumes without condensation and form cyanhydric acid. To prevent the partial decomposition of the acetylene it is well to add to the mixture a quantity of hydrogen equal to about ten times the volume of the acetylene. The reaction is expressed by the equation

€2H2+N2=2¤NH.

The reaction in this case begins rapidly but soon slackens. A definite volume of acetylene may be made to disappear completely by putting a drop of a solution of potash into the vessel before passing the stream of sparks. The cyanhydric acid is then absorbed as fast as formed, and about five sixths of the acetylene is converted into cyanhydric acid, the other sixth being decomposed into carbonic acid and oxyd by the vapor of water present. The effect of cyanhydric acid in preventing the action in this case is due to the fact that a mixture of cyanhydric acid and hydrogen gives under the influence of the stream of sparks acetylene, or a reaction the inverse of that first described. Having observed that all hydrocarbons are decomposed by the spark with formation of acetylene, Berthelot inferred that nitrogen would give cyanhydric acid with the vapor of any hydrocarbon, and this was fully verified by experiment. In the presence of potash two or three minutes' passage of the spark suffices to give the reaction due to the formation of Prussian blue.-Comptes Rendus, lxvii, 1141.

W. G.

9. On the Ammonium-amalgam.-LANDOLT has made a series of experiments to ascertain the composition of the ammoniumamalgam. It was prepared from a solution of ammonic chlorid by

electrolysis in the ordinary way, the negative electrode being connected with mercury contained in a porous cup filled with the ammoniacal liquid, while the positive electrode dipped into mercury in an outer glass vessel, also filled with the solution of chlorid of ammonium. When the current from 6 to 10 Grove's cells was employed, the positive electrode became covered with a layer of calomel, while the mercury in contact with the negative electrode slowly increased in bulk, evolving no gas until the point of saturation was reached. Landolt first determined the ratio of the ammonia gas evolved to the hydrogen, by placing the amalgam in dilute hydrochloric acid of known strength, and measuring the hydrogen evolved. The ammonia was then calculated from the quantity of the acid which it saturated. To free the amalgam from the ammonia contained in the solution, it was washed with water; but as the decomposition continued and only the hydrogen escaped, it was evident that the ammonia thus retained must give too high a result. The first experiment gave 1:2:15 as the ratio between the hydrogen and the ammonia by volume. The second, in which the amalgam was less quickly placed in the acid,-gave the ratio 1:24. These results, which entirely confirm those of Davy, establish, as Landolt believes, the conclusion that the compound NH, is taken up as a whole by the mercury. This is proved by the above ratio, because, were the gases separately absorbed, they would be set free again in very different proportions. In the second place, Landolt attempted a determination of the amount of the ammonium thus combined with the mercury. The amalgam was placed in a standard dilute hydrochloric acid as before; the ammonium was calculated from the quantity of acid neutralized and the mercury was determined by collecting and weighing it. The results varied from 054 to 090 per cent of NH4, owing to the rapid decomposition which took place. Evidently the maximum result is nearest the truth; and if 100 parts of mercury take up 0.09 parts of NH4, the amalgam in decomposing should yield for each volume of mercury 15.2 volumes ammonia and 7.6 volumes hydrogen; numbers which hold good for the compound prepared at ordinary temperatures. On the metallic nature of ammonium, too, Landolt made some experiments. Starting with the well known fact that potassium or sodium-amalgam will throw down most metals from solutions of their salts, he argues that the ammonium-amalgam, if analogous, should do the same. Freshly prepared ammonium-amalgam was placed in the metallic solution, the separated mercury was washed with water, dissolved in nitric acid and examined for the metal whose solution had been used. The result with cupric sulphate, argentic nitrate, and ferric chlorid solutions was entirely negative, though at least 100 grams of the amalgam was employed. While therefore NH combines as such with the mercury, its metallic character is doubtful; further researches only can decide its nature. —Ann. Chem. Pharm., Suppl. Bd. vi, Heft 3, p. 346, Dec. 1868.

G. F. B.

10. On a new method for preparing Carbonylic Sulphid.-LaDENBURG has communicated to the Chemical Society of Berlin a new method for the preparation of carbonylic sulphid gas. From theoretical considerations he was led to search for a body containing the group COS, thinking the atoms might be differently arranged from that in Than's compound. He finds that Kekulé's thiacetic acid, in which this grouping of atoms occurs, is decomposed by electrolysis, by heat, or by the action of bromine. The first is the most certain in its results, but it requires a large quantity of material. The action of bromine he had not yet fully studied. The action of heat on thiacetic acid had already been studied by Kekulé and Ulrich, up to 180° C., and they observed the production of HS. Ladenburg employs a temperature of 300°; the gas evolved is a mixture of carbonylic sulphid with hydric sulphid, the latter constituting about of the whole volume. After the absorption of these a small quantity of a combustible gas remained, which was not accurately analyzed. In the tube a black coaly mass is left which shows that the decomposition is one not to be expressed by a chemical equation.--Ber. d. deutsch. Chem. Ges. zu Berlin, ii, 53, Feb. 1869.

G. F. B.

The

11. On Carbonylic Sulphid.-BENDER has studied the deportment of carbonylic sulphid with alcoholic solution of potassic hydrate. This gas, prepared according to the method of Than,* and purified by passing through a U tube filled with unvulcanized caoutchouc and immersed in a freezing mixture of pounded ice and hydrochloric acid-was conducted into a cooled concentrated solution of potassic hydrate in alcohol. It was completely absorbed and after a time the fluid solidified to a crystalline mass. crystals were placed on a filter, dried with blotting paper and recrystallized from alcohol. White needle-shaped crystals were obtained which closely resembled potassic xanthate and afforded on analysis the formula €,H,KSO2. This salt is easily soluble in alcohol and water-though not deliquescent-and insoluble in ether. At 170° C. it decomposes into carbonylic sulphid, ethylic sulphid, and potassic carbonate, according to the equation:

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The same salt apparently, was obtained by Debus by decomposing ethylic sulphocarbonate with alcoholic potash, thus:

¤S2O(¤ ̧H5)2+HKO=¤S02(€2H ̧)K+H(¤2H ̧)S; and by Chancel by passing carbonic gas into an alcoholic solution of potassium mercaptid. Its possible rational constitution may be represented in three ways, thus:

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*This Journal, II, xlv, 251, March, 1868.

Its formation from carbonic dioxyd and potassium mercaptid, as well as from carbonylic sulphid; its decomposition also, both by heat and in watery solution, prove that it contains the radical €. But while its decomposition into ethylic sulphid by the action of heat would seem to indicate that the sulphur was united with the ethyl, its yielding potassic sulphid when heated in aqueous solution suggests that the sulphur and potassium are united. Both reactions render it improbable that the sulphur is held to the carbon by both its units of attraction. Between the two formulas €0<sK Ꮎ€ H -5 and € K SCH, 2 5 future researches must decide.Ann. Ch. Pharm., cxlviii, 137, Nov. 1868.

G. F. B.

12. On carbonylic chlorid, and a new compound of this substance with platinum.-SCHÜTZENBERGER, in attempting the direct synthesis of carbonylic chlorid by passing a mixture of dry carbonous oxyd and chlorine gases over heated platinum sponge, noticed that beside the phosgene gas thus formed, there was produced a large quantity of a solid platinum compound which was deposited in the cooler portions of the tube, forming either a fused yellowish-brown ring-which crystallized on solidifying-near the heated part, or being carried on and deposited all along the tube as a clear yellow flocculent powder, which soon obstructs the tube. Heated to 150°, this powder melts, yielding a reddish-yellow liquid, which again solidifies on cooling to a reddish-yellow crystalline mass. By varying the conditions a second product was obtained which melted at 130°. The former substance on being heated nearly to redness, is decomposed into metallic platinum and a mixture of carbonylic chlorid and carbonous oxyd gases, though a portion is at the same time sublimed and is deposited again as a dark yellow liquid which solidifies to a nearly colorless crystalline mass. Exposed to moist air it is blackened in a few minutes. Water decomposes it with effervescence, evolving carbonic dioxyd and carbonous oxyd gases, precipitating finely divided platinum, and holding hydrochloric acid in solution. The crude product yielded on analysis from 61.57 to 62.3 per cent Pt 22.7 to 23.8 Cl, and 5.22 €; and after crystallizing it from solution in carbonic tetrachlorid-dried over sodium-it gave 63.5 to 63.7 per cent Pt, 22.9 to 23.4 per cent Cl, 4:55 to 5.3 per cent €, being nearly identical with the former. This analysis yields the formula (CO), Pt, Cl, and not COPtCl which Schützenberger had at first proposed. Its chemical constitution is very easily and naturally obtained; two atoms of quadrivalent platinum are united by three links of bivalent carbonyl into a closed chain, having four free bonds, which are saturated by chlorine. It is hence a di-platino-carbonylic tetrachlorid, while COPtCl2 would be platino-carbonylic dichlorid. Possibly on heating the former compound it may evolve € and yield the latter, thus:

(¤Ð) ̧Pt2Cl ̧=(€0PtCl2)2+€0.

Schützenberger gives also the following syntheses of phosgene; (1.) By heating an excess of carbonic tetrachlorid with zincic oxyd

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