1890 Coca and its Therapeutic Application by Angelo Mariani

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Properties.—Cocaine is colorless, odorless, and bitter to the taste. It crystallizes in the shape of oblique rhomboid prisms of from four to six facets. It is very soltible in water, less soluble in alcohol, and absolutely insoluble in ether. It does not vaporize below 98°, but if the temperature is greatly increased it is decom posed. It possesses a strongly alkaline reaction. United with acids it forms salts which are very difficult to crystallize. Those which have been obtained from it are; the salicy- late, oxalate,hydrobromide, sulphate, acetate, and finally the hydrochlorate,which forms an exception to the general rule, and is obtained more easily in the crystalline form than any other. The solutions of the salts of Cocaine are precipitated by the caustic alkalies, carbonate of sodium,carbonate of am monium,the alkaline bicarbonates,the bichloride of mer cury,the protochloride of tin, bichloride of platinum, and by ammonia,which,added in excess,redissolvesthe precipi tate formed by it. Iodine water,iodized potassium iodide, and picric acid precipitate the solutions of salts of Cocaine. When Cocaine is heated to 100° in a sealed tube with con centrated hydrochloric acid, it separates into benzoic acid and a new base,for which M.Woehler has proposed the name of Ecgoninc. Lassen has discovered another nitroge nous base resulting from the separation of Cocaine— hygrinc. Preparation.—The process used by Niemann for obtain ing Cocaine is as follows; This chemist digested Coca leaves, cut into very small pieces, in alcohol (at 5.1°), for several days, adding sul phuric acid. The tincture which resulted from this op eration was separated by expression, filtered, and treated with slaked lime. The liquid, which was primarily of a greenish-brown, was both divested of a part of its chlbro- phyll and also of a certain waxy substance. Niemann