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 1875) this thankless task. Others before him had experimented in various ways. Two Austrian scientists, Hlasitwetz and Habermann, in 1873, and a little later Drechsel in 1892, had used concentrated hydrochloric acid to break down albumin. They also employed bromine for the same purpose. More recently Fuerth had used nitric acid with a similar object. Schützenberger tried another way. The battering ram which he used against the edifice of albumin was a concentrated alkali, baryta. He warmed the white of an egg with barium hydrate in a closed vessel at a temperature of 200°. The albumin of egg then divides into a certain number of simpler groups. The difficulty is to isolate and to recognize each part in this mass of the materials of demolition. That can be done by the aid of the processes of direct analysis. By mentally combining these different fragments, the original building is reconstructed. This method of demolition is certainly too rough and violent. Schützenberger's operation gives us very fine fragments—small molecules of free hydrogen, of ammonia, of carbonic, acetic, and oxalic, acids which reveal extreme pulverization. These products represent about a quarter of the total mass. The other three-quarters are formed of larger fragments, the examination of which is most instructive. They belong to four groups. The first comprises five or six bodies, amido-acids or leucins. It proves the existence in the molecule of albumin of compounds of the series of fats—i.e., arranged in an open chain. The second group is formed by tyrosin and kindred products—i.e., by the bodies of the aromatic series, which force us to acknowledge the presence in the molecule of albumin of a benzene nucleus. The third