110 CHEMISTRY OF THE PROTEIDS CHAP. 



such a way that the component occurring normally in the body was 

 oxidised as far as it could be assimilated, while the anormal (' korper- 

 fremde') component was excreted partly or completely in the urin. 

 If, for example, the tyrosin occurring normally in animals is the 

 dextro-rotatory tyrosin, then it would be acted upon, while the laevo- 

 rotatory tyrosin which accompanies it in the raceme-tyrosin would be 

 eliminated. 



The part played by kreatin and kreatinin in metabolism is 

 discovered by Czernecki, 1 while the fate of indol and skatol, when 

 introduced into the body, has been studied by Grosser. 2 



Umber 3 believes to have altered the composition of albumin in 

 the body during starvation by the administration of benzoic acid. 

 The latter, by linking on to glycocoll, gives rise to hippuric acid, 

 which, being excreted by the kidney, leads to a diminution in the 

 glycocoll-context of albumins. Abderhalden, Bergell, and Dorphing- 

 haus 4 do not agree with this, but the possibility of altering the 

 composition of albumins is beyond doubt, for, apart from the 

 histological evidence which the author possesses and which shows 

 that it is possible to excite or suppress nuclear activity at will, 

 and apart also from the evidence that protamins are derivatives of 

 ordinary albumins (see p. 420), there is the strong evidence adduced 

 by Wakemann, 5 who has shown phosphorous-poisoning to attack that 

 nucleus of the albumin-molecule which contains most nitrogen, as is 

 proved by the fact that the amount of arginin, histidin, and lysin 

 becomes diminished to a greater extent than does that of the mono- 

 amino-acids. The albuminous substances which are left behind in 

 phosphorous - poisoning are poorer in nitrogen and in the basic 

 constituents of the cell. 



In the following pages the action of intracellular enzymes on 

 the albumin molecule will be discussed. 



Kossel in 1898 6 first expressed the opinion that proteolytic 

 ferments might act on imide-groups of the albumin -molecule. In a 

 second paper 7 Kossel and Dakin divide ferments into two classes : 



1. Oxy-lytic ferments, which loosen the O-link by which the 

 radicals are kept together in the fats and carbohydrates. 



1 W. Czernecki, Zeitschr. f. physiol. Chem. 44. 294 (1905). 



2 P. Grosser, ibid. 44. 321 (1905). 



3 F. Umber, Berl. klinische Wochenschrift, No. 39 (1903). 



4 E. Abderhalden, P. Bergell, and Th. Dorpinghaus, Zeitschr. f. physiol. Chem. 41. 

 153 (1904). 



5 A. J. Wakemann, ibid. 44. 335 (1905). 



6 A. Kossel, ibid. 25. 188 (1898). 



7 A. Kossel and H. D. Dakin, ibid. 41. 321 (1904). 



