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REMARKS.

Seventh Month.-1. Cloudy. 2-4. Fine. 5. A thunder storm about two, a. m.: a very heavy shower about half past ten: the rain continued till about two, p.m. with very frequent thunder at a distance. 6, 7. Fine. 8. Cloudy. 9, 10. Fine. 11. Showery. 12-15. Fine. 16. Fine: night rainy. 17. Fine. 18. Fine: night rainy, with thunder. 19, 20. Fine. 21. Showery. 22. Fine. 23. Showery. 24-28. Fine. 29. Showery: some thunder. 30. Fine. 31. Showery.

RESULTS.

Winds: N, 3; SE, 2; S, 2; SW, 11; W, 3; NW, 8; Var. 2.

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ANNALS

OF

PHILOSOPHY.

OCTOBER, 1822.

ARTICLE I.

A preliminary Account of a new Class of Compounds of Sulphur. By W. C. Zeise, Doctor of Philosophy, and Professor of Chemistry in the University at Copenhagen.*

IF a certain quantity of sulphuret of carbon is poured into a solution of potash, soda, or ammonia, in alcohol, either pure, or containing a small portion of water, a neutral liquid is obtained, though the sulphuret of carbon by itself never shows any acid properties the reason is, that this sulphuret combines with other substances, and forms a new acid which is capable of neutralizing the alkalies. If potash has been used, the new formed salt may be obtained either by great refrigeration, or by evaporation, or it may be precipitated by sulphuric ether. The salt contains neither a trace of carbonic acid, nor sulphuretted hydrogen, but the acid in this compound is of a peculiar nature, and contains carbon, sulphur, and hydrogen; it is the same with respect to sulphuret of carbon that the hydrocyanic acid is with respect to cyanogen. I have called its compounds with bases hydrocarbosulphates. Some of the most remarkable properties of the hydrocarbosulphate of potash are the following:

This salt crystallizes in long needles, or in a fibrous mass, composed of similar crystals. It has a peculiar smell even after having been dried under the air pump; its taste is a little like sulphur, peculiar, however, and very strong; it remains dry in the open air, and is very soluble in water; the aqueous solution

*Extract of a paper read at the Royal Society at Copenhagen, May 17, 1822. New Series, VOL. IV.

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is colourless, and completely neutral. The salt is readily soluble in alcohol, but dissolves difficultly in sulphuric ether. Both solutions are also colourless and neutral. No gas is expelled by strong acids; but when sulphuric or muriatic is added to a concentrated aqueous solution of the salt, an oil-like liquid is separated, which has a rather yellow colour, and a peculiar strong smell.

1. The solution produces with the soluble salts of lead a white precipitate.

2. With the nitrate of barytes, muriate of barytes, muriate of lime, no precipitate at all.

3. With soluble salts of copper, a fine yellow precipitate. 4. With nitrate of deutoxide of mercury, sublimate and prussiate of mercury, a white precipitate.

5. With nitrate of deutoxide of tin, a yellowish precipitate. 6. With sulphate of zinc, a white precipitate, a little inclining to green.

7. With nitrate of silver, nitrate of protoxide of mercury, muriate of protoxide of tin, if the solutions are diluted, a yellowish, if concentrated, a brownish precipitate.

All these precipitates, except those of No. 7, keep their colour unchanged under the liquid, and in open air. None of them produce gas when treated with strong acids, but some give the above-mentioned oil-like substance. The hydrocarbosulphate of potash may be heated to 140° Fahrenheit without undergoing any observable change. When heated in close glass vessels, it melts, effervesces, assumes a fine light-red colour, and gives out, 1. an oil-like liquid of a yellow colour, and a peculiar strong and very penetrating smell; it does not show any acid properties when tried with tests, and does not produce a black precipitate with salts of lead; 2. Carbonic acid; 3. Another gas, which is either a mixture of sulphuretted hydrogen and a peculiar gas, or this latter alone: it is remarkable for its strong smell of onion. The red substance remains unaltered when cooled, but when the temperature is increased to a red heat, it melts, effervesces, and becomes brownish-black, and after some time ceasing to effervesce, the substance melts quietly. On cooling, the substance separates into two distinct portions; the lower and larger mass is crystalline and greyish-black; the upper is uncrystalline and black. During this change, besides gas, a great quantity of an oil-like liquid is given out. If the black substance is heated again, it melts, produces no oil-like liquid, and but little gas, even if the temperature is raised to a strong red heat. Afterwards it has no crystalline appearance.

The red mass above-mentioned dissolves easily in water without the least turbidness. In the beginning, the solution has a red colour, which, however, is soon changed into brown. In alcohol, it is difficultly dissolved; the solution is yellowishbrown. The red mass is alkaline, when tried by tests.

It

becomes moist in the open air, but not much so. The aqueous solution, when mixed with a solution of nitrate or acetate of lead, throws down a blood-red precipitate, which slowly changes into black, exactly as Berzelius has described. He obtained it when mixing nitrate of lead with an aqueous solution of potash that had remained during three weeks with a surplus of sulphuret of carbon.* Even when the solution of the red melted substance has assumed the brown colour, it produces a red precipitate with salts of lead; but, which is curious, the precipitate which has been thrown down by a brown solution blackens much quicker than that from a red solution. When a piece of the melted red substance before it has attracted moisture is thrown into a solution of nitrate of lead, the precipitate keeps its colour during several days, principally if, after it has been washed with water, alcohol is poured on it, and it is then quickly dried. When sulphuric, muriatic, or acetic acid is poured on the red mass, a violent effervescence takes place, and the smell of sulphuretted hydrogen is perceived, together with some other smell; an oil-like liquid separates, but neither pure sulphur nor pure carbon. By being exposed for about 30 hours to the atmosphere, it does not lose much of its colour, but in longer time it becomes yellow.

The greyish-black crystalline mass deliquesces quickly when exposed to the air, and when tried with tests, it shows free alkali. The aqueous solution is brownish-black without depositing any observable powder, but the intensity of its colour is so great that it only becomes transparent on being much diluted. When an acid is poured in it, it gives out a great quantity of gas which seems to be pure sulphuretted hydrogen; a great quantity of carbon is precipitated, and but little sulphur. None of the oil-like liquid appears. When a solution of it is exposed to the air, it remains more than 24 hours without getting turbid; afterwards carbon is precipitated, at last in great quantity, and the liquid becomes colourless.

The black mass deliquesces very readily, and contains free alkali. It dissolves easily in water, while a great quantity of carbon in flakes is deposed; the solution is first greenish-yellow, and at last, when sulphur has precipitated, it is colourless. When an acid is mixed with a recently prepared solution, sulphuretted hydrogen is expelled, and a great quantity of sulphur is thrown down. I consider the crystalline black mass prepared by heating the red substance to be a compound of potassium and a kind of sulphuret of carbon; the black uncrystalline mass is a mixture of sulphuret of potassium and carbon.

When the hydrocarbosulphate of potash is exposed to the heat of the flame of a candle, it inflames and burns, throwing about a great number of brilliant sparks. Two periods may be

* Afhandlingar i Fysik, Kemie og Mineralogie, 5 Deel, p. 266, &c.

distinctly observed in this combustion: during the first, it melts into a reddish-brown substance, which, when again inflamed, burns and throws the sparks still more violently around. The red mass itself is likewise combustible, and exhibits immediately violent combustion with white sparks. If the salt be thrown on red-hot glass, or charcoal, it is quickly consumed. I apprehend the cause of this phenomenon to be, that a compound of potassium and sulphur is suddenly formed, while carbon and a gas are separated, and that these small particles of carbon when thrown about produce the white burning sparks. I find this theory supported by the phenomena which take place when the salt is decomposed by heat in close vessels.

The hydrocarbosulphate of soda crystallizes more difficultly, and in a form quite different from that of the salt of potash; it deliquesces in moist air, and is not separated from its solution in alcohol by means of sulphuric ether; with acids and salts of metals, it exhibits the same phenomena as the hydrocarbosulphate of potash.

Hydrocarbosulphate of lime is obtained by mixing a solution of muriate of lime in alcohol, with a solution of the hydrocarbosulphate of potash; muriate of potash is precipitated, and the hydrocarbosulphate of lime remains pretty pure, dissolved in the alcohol; for though the muriate of potash is soluble in alcohol, the salt of lime almost entirely prevents its solution.

I consider the compounds that are separated when the hydrocarbosulphate of potash is mixed with solutions of certain metals to consist of the metal and a kind of sulphuret of carbon without oxygen. Zinc, however, may make an exception. The carbosulphuret of copper has a fine lively yellow colour, the carbosulphuret of lead and the carbosulphuret of mercury are white; the first, however, has a foliated, shining, crystalline appearance; the second is granular. The carbosulphuret of copper is prepared by pouring an aqueous solution of the hydrocarbosulphate of potash into a solution of sulphate or nitrate of copper. The precipitate, when washed with water, is pure. The carbosulphuret of lead is prepared in the same way from nitrate of lead, and the carbosulphuret of mercury from corrosive sublimate, or prussiate of mercury. They are all insoluble in water, but the carbosulphuret of lead and of mercury at least are soluble in alcohol. The carbosulphuret of mercury is soluble in a concentrated solution of the hydrocarbosulphate of potash, and it seems to form with it a saline compound. Strong acids act very slowly on these compounds, and by themselves they may be exposed to the heat of boiling water without being decomposed. When heated in a glass tube, the carbosulphuret of copper and that of lead produce at a certain temperature a mist in the vessel, which is condensed into a yellow liquid, with a smell like onions, and the exact appearance of oil; afterwards it melts, gives out gas with violent effervescence, and in considerable quantity; then

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