THE CHEMICAL UNITY OF LIVING BEINGS. 183 



1875) this thankless task. Others before him had 

 experimented in various ways. Two Austrian 

 scientists, Hlasitwetz and Habermann, in 1873, and 

 a h'ttle later Drechsel in 1892, had used concen- 

 trated 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. Schlitzenberger 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 2co°. 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. Schiitzenberger'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 frag- 

 ments, 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 



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