GANNAL, Jean Nicolas (1791-1852), a distinguished French technical chemist, was born at Sarre-Louis, July 28, 1791. At the age of fourteen he was placed in a druggist’s establishment, where he acquired a knowledge of chemical manipulation. In 1808 he entered the medical department of the French army, and in the campaign of 1812 he witnessed the disastrous retreat from Moscow. After the downfall of the empire he obtained a situation at the École Polytechnique in Paris, and subsequently acted as chemical assistant to Thénard. Having commenced research in industrial chemistry, he devised a method for the refining of borax, by which the price of that salt was reduced from 6 francs to 60 centimes per lb. He was the first to introduce into printing the use of elastic rollers, which he formed of a mixture of gelatin and sugar, and his process for the melting of tallow and hardening it with acids prepared the way for the manufacture of wax-candles. In 1823 he took out a patent for the making of glue and gelatin. His experiments with the latter substance demonstrated the incorrectness of the opinion, held by Darcet and others, that it possessed highly nutritive properties. He obtained one of the Montyon prizes of the Institute in 1827 for the employment of chlorine in the treatment of catarrh and phthisis, and again in 1835 for his discovery of the efficacy of injections of solutions of acetate and chloride of aluminium in preserving anatomical preparations. Turning his attention next to embalmment, he showed thatit could be accomplished without mutilation of the body, and with greater economy than after the old methods, by injecting into one of the carotid arteries solutions of aluminium salts. Gannal died at Paris in 1852. The following are among his works :—...