738 INTERNAL SECRETIONS AND PRESERVATION OP LIFE. 



ture at least that of the oxidizing substance. Evidence of this 

 is fortunately available. "It was supposed that the sensitizing 

 or intermediary substance was likewise the substance which 

 produced agglutination of the red corpuscles," writes Metch- 

 nikoff, 72 "but .searching investigations have thoroughly estab- 

 lished the difference between these two substances, which have 

 as a common characteristic the fact that they both resist heat- 

 ing at 55 to 60 C. and beyond." Evidently trypsin is not only 

 the agglutinating agency, but likewise that which destroys red 

 corpuscles, bacteria, toxins, etc. 



But if, as stated by Bordet, the alexin is not increased in 

 the serum of periodically injected animals and it is only the 

 sensitizing substance, our oxidizing substance, which appears 

 in "very great quantity," how can we account for the thirty- 

 fold hsemolytic power noted by de Dugern? It seems plain that 

 a relatively small quantity of trypsin should be quickly disposed 

 of under such circumstances, the haemolytic process ceasing 

 with corresponding promptness. But the fact that alexin can 

 so easily part with its trypsin as suggested by the first experi- 

 ments reviewed, on the one hand, and the correspondence be- 

 tween the temperature resistances of trypsin and the oxidizing 

 substance, on the other, point to the fact that the alexin ratio 

 of a serum may not in the least represent that of the trypsin 

 ratio. The blood of the injected animal may thus have con- 

 tained an ample supply to account for the great increase of 

 haemolytic power without showing an increase of alexin. 



Indeed, we must not, in all this, lose sight of the fact that 

 the conditions that prevail in extravasated blood do not portray 

 conditions as they exist in living blood, and that such experi- 

 ments can only be of value if, as in those referred to in the fore- 

 going pages, all the elements introduced by the separation of 

 the specimen from the intra corpore blood are taken into ac- 

 count. Thus, Martin and Cherry, 73 of Melbourne, refer to ex- 

 periments by Calmette 74 which led him to conclude that "the 

 toxin of snake-venom does not interact with its antitoxin in 

 vitro, but only in corpore, and, therefore, that its action cannot 



Metchnikoff : Loc. cit., p. 98. 



73 Martin and Cherry: British Medical Journal, Oct. 15, 1898. 



* Calmette: Annales de 1'Institut Pasteur, p. 250, 1895. 



