ische Anilin and Soda Fabrik, Ludwigshafen-on-Rhine, Germany. In the dyeing or printing of cellulose esters, and particularly of cellulose acetate silk, the ester is treated previously or simultaneously with a solution of an acid ester of a mineral oxygen acid, such as sulphuric, phosphoric or boric acid, or with a solution of a salt such as acid ester. In examples cellulose acetate silk is dyed by treatment first in a warm bath of potassium ethyl sulphate and then in a bath of Diamond Green B; by treatment first with sodium dicresyl phosphate and subsequent dyeing with Methyl Violet 2B, with or without waste sulphite cellulose liquor, or Azofiavine RS, or with a hydrosulphite vat of Indanthrene Blue GCD containing, if required, a protective colloid; and by treatment in a bath containing both sodium dicresyl phosphate and the dyestuff Auramine II. A further example shows the printing of acetate silk with a paste comprising Euchrysine 3R, dicresyl phosphate, acetine and gum.

device bearing word SIEROCASALI, for a medicinal remedy for human use in the treatment of Arteriosclerosis, Anaemia Decline, Infectious Diseases and Metabolic Disturbances.-Societa Preparati Casali ,67, Via Lucrezia Caro, Rome, Rome, Italy. November 25th, 1925.

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The addition of magnesium to a solution of ammonia alum, or copper sulphate causes slight evolution of hydrogen, undoubtedly from the sulphuric acid. Moreover with a saturated solution the discharge of gas is less brisk than with one more dilute. Too much water has of course the opposite effect. A 0.001 per cent. solution of sulphuric acid saturated saturated with ammonia alum gives off a faint stream of hydrogen with magnesium. This stream becomes a shower as water is added.

This evolution of hydrogen is much more rapid under the influence of electrolysis. It is still further accelerated by the addition of an equimolar amount of copper sulphate, so much so that it forms a potential field of research with regard to the making of sulphuric acid. A solution of an equimolar mixture of copper sulphate and ammonia alum coloured brown by methyl orange, turns pink round the anode immediately the current is switched on. This becomes stronger as the action proceeds, then strawberry, violet, blue violet, pale blue, and later, practically colourless. At this last stage there is no copper sulphate in solution. The methyl orange is either precipitated or bleached.

As electrolysis proceeds the alum is split up, ammonia given off which of course forms ammonium sulphate again and also aluminium hydrate. Addition of fresh copper sulphate, however, results in vigorous action, becoming still more so as copper is deposited. In seven hours, with ordinary lighting current, it is possible to obtain a 17% solution of acid, in addition to an abundant crop of copper.

As electrolysis removes water only, a stronger current would assist in concentrating the acid by this means, and also by virtus of the heat generated by the passage of greater current density.

THE REACTION BETWEEN BISMUTH TRISULPHIDE AND HYDROCHLORIC ACID.

By S. RAMACHANDRAN.

It has already been reported by me in previous papers on this subject (1) that bismuth trisulphide could not be precipitated from a solution of a bismuth salt in "concentrated" hydrochloric acid; (2) that bismuth trisulphide is easily soluble in concentrated hydrochloric acid in the cold with distinct liberation of sulphuretted hydrogen; (3) that bismuth trisulphide is quickly and completely acted upon by boiling hydrochloric acid of concentration 1: 5Aq.; and (4) that the evolution of sulphuretted hydrogen from bismuth trisulphide by the action of acid begins at increasing temperatures with increasing dilution of the acid.

The results obtained from a further qualitative study of this reaction are given in this paper.

EXPERIMENTAL.

(1) About 10 c.c. of hydrochloric acid of the approximate concentrations noted below were added to little quantities of the well-powdered pure product placed in several test-tubes. The latter were heated uniformly and carefully by placing them in a water-bath, the temperature of which could be easily controlled. The temperature at which the evolution of hydrogen sulphide commenced was noted in each case and it was found that it increased with increasing dilution, although powdering the substance produces a marked effect in that with an acid of a certain concentration hydrogen sulphide begins to be evolved at a lower temperature than when the substance is not powdered.

(2) To further prove the fact that hydrochloric acid of all concentrations (at least up to the ones now under investigation) act upon bismuth trisulphide even at our laboratory temperature (about 29 deg. C.), small quantities of the substance were placed in several test tubes and digested with 5.c.c. of acid of differing concentrations (above 1: 5Aq. up to 1: 16 Aq.) for not more than half an hour each--the temperature being kept constant by immersing the tubes in a water bath kept at 29 deg. C. The resultant turbid liquid was

was

filtered off in each case, boiled, and cooled. Through the filtrate a stream of sulphuretted hydrogen was passed, when it found that, in each case, there was a distinct precipitation of brownish-black bismuth trisulphide.

(3) Small quantities of the well-powdered substance were again digested in the cold for about half an hour with 10 c.c. of hydrochloric acid of different concentrations and the mixture filtered off. On merely diluting the clear filtrates, no precipitation was observed.

(4) Pure bismuth trisulphide was precipitated from a slightly acid solution of bismuth trichloride and the precipitate kept in contact with the liquid from which it was precipitated for about 48 hours. It was afterwards filtered off, purified, and dried. There was found to be no change in the behaviour of the substance towards hydrochloric acid showing thereby that the nature of the product is not altered by keeping it in contact with the medium from which it was precipitated.

Further experiments are being conducted on this subject.

-Contribution to the "Chemical News " from :

The Chemical Laboratory,
Ceded Districts College,

9 November, 1925.

ELECTROLYTIC REDUCTION OF OXIMES, III. BENZILDIOXIME.

By MASAYOSHI ISHIBASHI.

With the object of tracing the cathodic reactions which benzildioxime undergoes under various conditions, it was electrolysed both in the acid and in the alkaline solutions, using lead at the cathode. As we expected, reduction and hydrolysis take place side by side and many reduction-products were produced together. The ultimate reduction-product was diaminodiphenylethane which was obtained both in racemic and in meso-form. This fact is of interest when we compare it with purely chemical reduction which is reported to have produced the racemic form only. Other reduction-products such as diphenyloxyethlyamine (normal and iso), tetraphenylaldine, benzoinpinacone, desoxybenzoinpinacone, toluylenehydrate (iso) and hydrobenzoin (normal and iso) are all derived from the hydrolysed dioxime by reduction. Of these substances, tetraphenyl