On the Formation of Alcohol from Olefiant Gas. By M. Berthelot On the Substitution of the Aldehyde-radicals in Ammonia. By J. Natanson Compounds of the Ketones with Alkaline Bisulphites. By Dr. Limpricht. Photochemical Researches. By Professor Bunsen and H. E. Roscoe, B.A., Ph.D. On the Colour of Chloride of Copper in different States of Hydration. By THE QUARTERLY JOURNAL OF THE CHEMICAL SOCIETY. I.-Investigation of the Vegetable Tallow from a Chinese Plant, 66 the Stillingia sebifera." By NEVIL STORY MASKELYNE, M.A., F.G.S. DEPUTY READER OF MINERALOGY AND ASSISTANT PROFESSOR OF CHEMISTRY AT OXFORD. THE investigation now offered to the Chemical Society has been long made, as regards its most important features, but was not before published from a want of completeness in its details. That completeness has been now effected, and methods, introduced subsequently to the period of the original investigation, have been employed to establish its correctness. Chinese vegetable tallow is a substance used, I believe, already in considerable- quantities in the candle manufactures of this country, though the specimens first employed for this investigation were from the earliest imported cargo of it. It has been made the subject of examination by three chemists. Thomson and Wood,* and M. v. Börck,† have detailed the results of their labours upon it. The former two chemists imagined that they had established the nature of the solid fat acid in the Chinese tallow as consisting in a mixture of margaric and stearic acids; the latter, that he had shown it to be a new acid, to which he gave the name of stillistearic acid. That both arrived at erroneous conclusions will be seen from the following pages. M. Börck has given an account§ of the vegetable tallow itself, which is so complete that I am able to add nothing to it. J. pr. Chem. xlvii. 240. Ibid. xlix. 395. Since this paper was read I have received from Dr. Thomson specimens of the fat he examined, and of the acid he obtained from it, which render it evident that this fat was not the same with the tallow I have described in this paper. § Chem. Gaz. 1850, p. 647. VOL. VIII.- NO. XXIX. B The Stillingia sebifera, the Oka O of the Chinese, bears berries which are about a half-inch in length, united together in threes, surrounded by a triple capsule, which detaches itself very readily from the fruit. These berries consist of a stone-fruit, the kernel of which is protected by a hard shell, which again is coated by an envelope of cellulose substance, perhaps a quarter of an inch thick, in the cells of which the tallow is contained. This tallow-bearing envelope is estimated at about 25 per cent. of the fruit. The tallow is pressed out from the fruit by the Chinese, melted on water, and cast into large cylindrical moulds with a Chinese stamp on them. There is another product, a fluid fat, which is procured out of the more solidportion, and which does not come into commerce. The tallow of commerce, when freshly cut, is white, and becomes yellowish-brown by exposure. It possesses a faint but peculiar smell, calling to mind at once its fatty nature and vegetable origin. Its behaviour with solvents is as follows. The liquid portion of the tallow (its oleine) being soluble in the cold in various menstrua, imparts to them a solvent action on the solid portion also, which they otherwise do not possess; and hence, not only do oil of turpentine and coal-naphtha dissolve it entirely, but it is also partially soluble in ether, in equal parts of ether and absolute alcohol, ether and common alcohol, wood-spirit, absolute alcohol, and common "strong alcohol." The order in which I have placed these menstrua indicates the order of solubility, which is, of course, inversely as the amount of solid fat which remains undissolved. On boiling, it is completely dissolved by ether, by ether and absolute alcohol (equal parts), ether and common alcohol, absolute alcohol, wood-spirit, and in common alcohol,―the facility of solution being indicated by the order of the solvents. The ethereal solutions remain clear after cooling, and only ultimately deposit the cauliflower crystals, which are formed immediately in the other solutions. Heated in a capillary glass tube, it melts at 37° C., and beginning to solidify at 32° C., is finally hard at 26° C. But if carefully melted in a test-tube, the fresh tallow, or this after it has been melted and very slowly cooled, has a melting-point as high as 44° C. The melted tallow has an acid reaction. This might be due to a decomposition of the fat-salts in the tallow, or, again, it might be the result of an acid fat-salt. That it was not due to the former is rendered probable by the absence of glycerine from water on which the tallow had been kept for some time melted, the evaporation of this water yielding no acroleine odour. When, however, the tallow has been so boiled on water, it imparts |