ALBUMINATES 



125 



koilin. The fibroin A came from ordinary silk ; fibroin B and the sericin 

 originated from Indian Tussah silk. 



C. Cleavage Products of Simple Proteins. 



On the hydrolysis of proteins by the aid of acids, alkalies or by 

 enzymes, cleavage products are obtained which represent various inter- 

 mediary steps between the native proteins on one side and the simple 

 cleavage products, the amino-acids, on the other side. Among these 

 products we have for a long time known two chief groups which still 

 retain, to a high degree, their protein character, namely, the albuminates 

 and the proteoses (and peptones). 



1. Albuminates. 



Alkali and Acid Albuminates. The native proteins are modified 

 by the action of sufficiently strong acids or alkalies. By the action of 

 alkalies all native albuminous bodies are converted, with the elimina- 

 tion of nitrogen, or by the action of stronger alkali, with the extraction 

 of sulphur also, into a new modification, called alkali albuminate. If 

 caustic alkali in substance or in strong solution be allowed to act on a 



1 Cited from Abderhalden's Lehrbuch d. physiol. Chem., 1909. 

 2 Cohnheim, Chemie d. Eiweisskorper 3 d. Aufl. 



3 Skraup and Biehler, Monatsh. f. Chem., 30. 



4 K. B. Hoffmann and Pergl. Zeitschr. f. physiol. Chem., 52. 

 6 v. Knaffl-Lenz, ibid., 52. 



6 Abderhalden and Spack, ibid., 62. 

 7 Strauch, ibid., 71. 



8 E. Fischer, ibid., 53. 



9 Calculated as arginine. 



10 This figure is somewhat uncertain. 



