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and is converted into the neutral salt, which remains undissolved, and free salicylic acid, which dissolves in the water. Ether decomposes it in a similar manner at ordinary temperatures.

The neutral copper-salt obtained in the manner above described by the decomposition of the acid salt, is a light, nearly insoluble powder, of yellowish-green colour: its formula is C14H4Cu2O6+2 Aq.

Piria has likewise obtained two neutral salicylates, in which the two equivalents of base are formed by different metals, viz., a potassiocupric salicylate, C14H4KCuO+4 Aq., which crystallises in beautiful emerald-green laminæ, and baryto-cupric salicylate, which forms a crystalline powder containing C14H4BaCuO+4 Aq.

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On some Compounds of Hydrosulphate of Mustard-oil.*
By H. Will.

In a memoir on the essential oil of black mustard,† the author has demonstrated the existence of a compound of that oil with sulphuretted hydrogen, having the formula CH NS2. H2S2. Gmelin‡ denominates this compound Sulphosinapic acid; Gerhardt§ regards it as sulphocarbamic acid in which 1 eq. hydrogen is replaced by allyl, CH; thus :—

Sulphocarbamic acid.
NH2 (CS)2. S

H.

S

Allyl-sulphocarbamic acid.
NH (C6H5) (CS)2. S

H.S

According to Will's formula, it is sulphocyanide of allyl combined with sulphuretted hydrogen

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Will formerly obtained the compound by the action of an alcoholic solution of potash upon oil of mustard, it being then produced, together with carbonic acid and an oily body, C14H14N2S2O2, in the manner represented by the equation

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On separating the oily body, neutralising with acetic acid, diluting the

* Ann. Ch. Pharm. xcii. 59.

+Ibid. lii. 30.

Handb. d. Chem. 4. Aufl. v. 207.

Traité de Chimie Organique, ii. 203.

solution with a large quantity of water, and adding acetate of lead, a lemon-yellow, very unstable lead-salt is thrown down, whose analysis HS leads to the formula C ̧H ̧NS2+ Pbs. From the author's more recent experiments, it appears that the whole of the mustard-oil may be readily converted into the sulphur-acid by treating it directly with alcoholic solutions of metallic hydrosulphates. In this manner the following compounds have been obtained, the analyses of which confirm the composition of the acid previously deduced from the leadsalt:

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When oil of mustard is dropped into a saturated and colourless solution of hydrosulphate of ammonium in strong alcohol, its odour is instantly destroyed, the liquid becomes strongly heated, and in a few seconds solidifies to a crystalline magma composed of colourless needles of the double salt.

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This salt is not very stable, but, like the following compounds,

decomposes spontaneously by keeping.

Oil of Mustard with Hydrosulphate of Potassium :

CHONS K C2H } S2+ H} S2.

C6H5

K

An alcoholic or aqueous solution of hydrosulphate of potassium, to which oil of mustard has been added as long as the odour of the latter disappears, yields by slow evaporation in vacuo (provided the quantity of salt present is not too small) large rhombic tables, often an inch in diameter; by quicker evaporation, needle-shaped crystals are formed. These crystals, while immersed in the liquid, are transparent and colourless, but on exposure to the air become opaque and yellow, losing their form and becoming partially insoluble in water, which then leaves a sulphur-yellow mass. The aqueous solution of the

recently-prepared salt may be heated without evolving the odour of mustard-oil; if it be heated and then mixed with nitrate of silver, sulphide of silver is precipitated, and the odour of mustard-oil becomes immediately perceptible. The dry compound likewise gives off mustard-oil when heated :

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Oil of Mustard with Sulphide of Potassium.-a. C ̧H.NS2+2KS. -An alcoholic solution of monosulphide of potassium mixed with oil of mustard, the former being in slight excess, deposits by gentle evaporation a white granular salt, which, when heated, gives off oil of mustard, without changing its colour. It gave by analysis 39.2 per cent. of potassium; the formula requires 37.4.

b. CH5NS2+KS.-The mother-liquor from which the preceding salt has separated, yields, when -left to stand over sulphuric acid in vacuo, needle-shaped crystals having a scarcely perceptible tinge of yellow they behave like the preceding salt, but contain less potassium. Analysis gave 25·5 and 25·0 per cent. potassium, the formula b requiring 25.4.

It appears, then, that oil of mustard forms crystallisable salts, not only with the hydrosulphates, but also with the monosulphides of metals, and that the combination with the latter takes place in more than one proportion.

Oil of Mustard with Hydrosulphate of Sodium :

C ̧H ̧NS2 · Na}S2+6HO.

This compound is readily obtained by mixing a warm alcoholic solution of hydrosulphate of sodium with oil of mustard till the odour of the latter is no longer destroyed. It separates in nacreous laminæ which are greasy to the touch, and, when heated, first melt, and then give off a large quantity of mustard-oil. The salt contains water of crystallisation, and, like the preceding, cannot be preserved without decomposition.

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Oil of Mustard with Hydrosulphate of Barium :

C6H5NS2. Ba} S2+4HO.

H

This salt is produced by adding oil of mustard to a solution of sulphide of barium supersaturated with sulphuretted hydrogen and mixed with a small quantity of alcohol, or by passing sulphuretted hydrogen gas through water mixed with alcohol, in which hydrate of baryta and oil of mustard are suspended; it is likewise deposited from the mother-liquor of the following less soluble salt containing monosulphide of barium. The more soluble salt forms crystalline laminæ, resembling those of the sodium-salt:

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Oil of Mustard with Sulphide of Barium: CH¿NS2. 2 BaS+2HO. -When oil of mustard is gradually added to a yellow heated solution of sulphide of barium-such as is obtained by treating crude sulphide of barium with water-till the odour remains permanent, and the liquid filtered, the filtrate yields, on cooling, colourless or slightly yellowish lamina, which crumble to a white powder on exposure to the air. This compound is also precipitated by alcohol. The salt smells of oil of mustard, does not melt when heated, but burns away with a glimmering light at a higher temperature. Two analyses made with the salt dried by repeated pressure between paper

gave 491 and 47.3 per cent. barium; the above formula requires 47.94.

This compound appears to be capable of crystallising with a different amount of water, inasmuch as a salt obtained in another preparation gave only 41.6 per cent. barium, which corresponds with the formula CH,NS2. 2BaS+6HO (calculated quantity of Ba=42·6).

Oil of Mustard with Hydrosulphate of Calcium.—When milk of lime is mixed with oil of mustard, and a little alcohol added to dissolve the latter, the mustard odour disappears entirely on passing sulphuretted hydrogen through the liquid to supersaturation. A clear solution is then obtained, which, when evaporated over the water-bath, yields the calcium compound in the form of a slightly yellow transparent jelly. When perfectly dried, it falls to pieces, and gives off abundance of oil of mustard.

On Phillyrin.*

By C. Bertagnini.

THIS substance is obtained by treating the decoction of Phillyrea bark with lime or oxide of lead, and evaporating the liquid to a certain point, the phillyrin then separating after a while in the crystalline ·

state.

Pure phillyrin is nearly tasteless; it dissolves very sparingly in cold water, with tolerable facility in hot water, readily in alcohol, but not in ether. Its solutions are not precipitated by those of metallic salts. Ammonia and the fixed alkalies have no action upon phillyrin, but mineral acids readily decompose it. When phillyrin is boiled with dilute hydrochloric acid, a resinous substance is produced, which separates in drops, and a liquid, which, when treated with Trommer's test-liquid, produces an abundant separation of cuprous oxide. Now as phillyrin and the resinous substance separated from it do not act on this test-liquid, it appeared probable that phillyrin is a substance of more complex constitution,-like amygdalin, salicin, &c.,—and capable, like these bodies, of yielding sugar as one of its products of decomposition.

When phillyrin is heated with a proper quantity of dilute hydrochloric acid, till the separation of resinous matter has ceased, the liquid neutralised with carbonate of lead, the filtrate evaporated, the residue exhausted with alcohol, and the alcoholic solution evaporated over the water-bath, a sweet syrup is obtained, which in a few weeks solidifies into a warty crystalline mass, exhibiting all the characters of grape-sugar.

* Ann. Ch. Pharm. xcii. 109.

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