Page:Popular Science Monthly Volume 42.djvu/62

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an optical isomery identical with that of malic and tartaric acids. Sometimes the sugars present a right isomery, a left isomery, and an isomery inactive "by compensation, and a splitting into two sugars, one right and the other left. This is exactly what we have witnessed in right and left tartaric acids, the union of which constitutes paratartaric acid, inactive by compensation. It is not useless to insist upon this resemblance, and to remark that the reactions which have permitted us to effect the synthesis of the principal sugars are of a purely chemical character, and that they demonstrate that the chemist can reproduce substances endowed with the rotatory power and aside from all intervention of life. The sugars, reproduced by synthesis, remain proteic or albuminoid substances. Here, again, the prophets of vital force are found wanting.

M. Grimeux in 1885 had prepared synthetically, by the action of oxychloride of phosphorus upon a mixture of leucine and tyrosine, and further treatment with NH3 (ammonia), an amorphous, colloid substance, offering some of the characteristic reactions of albumen: precipitation on ebullition, the xanthoproteic reaction, the reaction of Millon, and the biuret reaction (soda and sulphate of copper). But M. Schutzenberger has just made a considerable step in the synthesis of those substances. A note in the Comptes rendas of the Institute of January 26, 1891, exposes the results of a successful experiment in the synthesis of a proteic substance presenting all the physical and chemical characteristics of the peptones.

An extended series of researches on the products resulting from the decomposition by hydration of proteic substances, albuminoid or other, under the influence of alkalies (baryta), have led M. Schutzenberger to attempt the synthesis of a proteic substance, starting from the simple terms of its decomposition by hydration. After numerous fruitless attempts he succeeded in forming a nitrogenous compound, which by its characteristics should be placed in the class of proteic substances, by combining, with the elimination of water, the ultimate and crystallizable products arising from the decomposition of albumen and fibrin under the influence of baryta. After a series of operations, of which I do not recite the detail, Schutzenberger obtained an amorphous product, soluble in water, precipitable by alcohol into white, cheesy lumps. The body thus obtained exhibited great characteristic similarities with the peptones. Its physical characteristics, its chemical reactions, and its modifications under the influence of heat, were faithfully like those of proteic substances. A great advance has therefore been made toward synthesis of organic substances, and the future promises still more complete results.

The chemist has then been able to realize the construction of