LIVING AND DEAD PROTEIN 569 



sumption of oxygen apparently serves as an index of the 

 intensity of the regenerative processes in the blood. 33 



There is an interesting point in the fact that the ability 

 of the body to reduce atoxyl to a trypanocidal substance 

 (which is in immediate relation with its therapeutic effects) 

 is, according to the studies of Levaditi and Yamanouchi, 

 evidently connected with the blood. 34 



The fact that the iron-bearing red corpuscles are the ele- 

 ments which dominate the consumption of oxygen by the 

 blood seems to have given fresh reason for the belief, which 

 for the last hundred years has been constantly recurring, 

 of the importance of iron in connection with animal oxida- 

 tions. Yet it is clear that this factor may be overestimated, 

 when it is recalled that sea-urchin spermatozoa, which are 

 very closely analogous to young red blood cells in this matter 

 of oxygen consumption, have been found to contain no iron. 35 



In the end we invariably come back to the recognition of 

 the fact that the power of conducting the vital combustion 

 processes is an innate peculiarity and function of living 

 protoplasm, a truism which in reality, to be honest, is strictly 

 not something which we know but rather a standing witness 

 to our lack of knowledge, a fact which cannot be hidden by 

 the most brilliant definitions and hypotheses of natural 

 philosophy except in the most pitiful manner. 



Living and Dead Protein. We contrast the "living pro- 

 tein " of Pfliiger (the "active protein " of Low or "biogen" 

 of Verworn) with the ordinary i i dead ' ' protein. The living 

 protein is held to be distinguished by special lability, as to 

 the cause of which different hypotheses have been promul- 

 gated. Pfliiger believed that the carbon and nitrogen atoms 



33 P. Morawitz, Arch. f. exper. Pathol., 60, 298, 1909; Deutsch. Arch. f. 

 klin, Med., 100, 191, 1910; 103, 253, 1911; S. Itami (Med. Clinic, Heidelberg), 

 Arch. f. exper. Pathol., 62, 93, 1910; O. Warburg (Med. Clinic, Heidelberg), 

 Zeitschr. f. physiol. Chem., 69, 452, 1910; M. Onaka, ibid., 7Jf, 193, 1911. 



34 T. Yamanouchi, C. R. Soc. de Biol., 68, 1910. 



85 E. Masing (Zoolog. Station, Naples, and Med. Clinic, Heidelberg), 

 Zeitschr. f. physiol. Chem., 66, 262, 1910. 



