66 



PHYSIOLOGICAL CHEMISTRY 



ysis of ingested protein of animal or vegetable origin. Experi- 

 ments, however, by Abderhalden and by Grafe and Schlapfer and others 

 indicate that the nitrogen of food protein may in part be replaced by 

 ammonium salts. Experiments by Osborne and others also indicate 

 amino acid synthesis by animals. 



Important data regarding the decomposition products of the protein 

 molecule are given in the tables which follow. 



COMPARISON OF THE DECOMPOSITION PRODUCTS OF PROTAMINES, AND 



OTHER PROTEINS. 



When we examine the formulas of the principal members of the 

 crystalline end-products of protein decomposition we note that they are 



1 Kossel: Zeit. physiol. Chem., 44, 347, 1905. 

 'Osborne and Guest: Jour. Biol. Chem., 9, 425, 1911. 

 8 Abderhal4en, Kossel and others. 



4 Abderhalden, Fischer, Morner and others. 



5 Fischer, Levene and Aders: Zeit. physiol. Chem., 35, 70, 1902; also Levene and Beatty: 

 Ibid., 49, 252, 1906. Dakin: Jour. Biol. Chem., 44, 449, 1920. 



Abderhalden: Zeit. physiol. Chem., 37, 484, 1903. 



'Osborne and Liddle, Am. Jour. Physiol., 26, 295, 1910. 



'Osborne and Leaven worth: Unpublished data furnished by authors. 



"Osborne, Van Slyke, Leavenworth and Vinograd: Jour. Biol. Chem., 22, 259, 1915. 



10 Roughly estimated. 



11 Osborne and Liddle: Am. Jour Physiol., 26, 295, 1910. 



* This unique and important protein has probably been more carefully analyzed than 

 any other. 



