VENOM ELEMOLYSIS AND VENOM AGGLUTINATION 165 



In the investigations cited in the foregoing pages the primary object was 

 to determine whether snake venoms act destructively upon the cellular ele- 

 ments of the blood, either infra corpore or extra corpore. Although their 

 modes of determining the injurious effects of venom upon the blood corpuscles 

 did not allow earlier investigators to work it out in a quantitative way, enough 

 data were accumulated to conclude the presence of more or less destructive 

 agents in various venoms thus tested. Haemolysis and also agglutination in 

 certain cases have been clearly demonstrated. In the meanwhile the era of 

 antitoxin and immunity was making rapid progress along all sides of pathol- 

 ogy, resulting coincidentally in the preparations of antivenomous serums, 

 first by Calmette, then by Fraser, Lamb, McFarland, Flexner and Noguchi, 

 Brazil, Ishizaka, and Kitashima; and it was natural that antivenomous serum 

 should be drawn into the study of the haemolytic property of snake venom 

 with brilliant results. 



As I will give attention to the immunity questions in later chapters I will 

 not discuss at length the relation between antivenin and venom under the pres- 

 ent head, but it is necessary to recognize here the great influence, direct or in- 

 direct, exerted by the Ehrlich school on the study of venom haemolysis. The 

 accurate techniques for determining the strength of toxin and antitoxin in 

 general had been established by Ehrlich and his pupils, and we were thus 

 enabled to distinguish the specific affinity of a given antitoxin to a group of 

 toxins which otherwise would not have been discriminated. Take snake 

 venom, for example: the venoms of different species dissolve the blood cor- 

 puscles of a certain animal in a similar fashion, and it would be impossible 

 to distinguish the hoemolytic principle of one venom from that contained in 

 another kind, unless a specific antivenin is used to differentiate them. The 

 same holds good for the toxic constituents other than haemolysin contained in 

 different snake venoms. No wonder, therefore, that pre-antitoxin investiga- 

 tors were often led to regard the active principles for various sets of cells and 

 tissues as identical in any kind of snake venom. Even after the introduction 

 of antivenin in the study of venom, earlier investigations not unfrequently 

 failed to reveal specificity, and it is evident that this was, to a great extent, 

 due to the lack of pure antitoxins, and also, to a small extent, due to the par- 

 tial specificity which easily might have evaded differentiation by a less strict 

 quantitative technique of standardization. 



The test-tube experimentation with haemotoxic substances was employed 

 first by Ehrlich in his famous studies on ricin and abrin and their antiserums. 

 Of haemolytic substances, Madsen, under Ehrlich, introduced a colorimetric 

 measurement for determining the quantity of liberated haemoglobin in the 

 fluid containing red corpuscles and tetanolysin, thus enabling observation 

 of the intensity of destruction of the corpuscles by the lysin. 



The calorimetric estimation of the haemolytic strength of snake venom 

 was first employed by Myers and Stephens 1 in their study on cobra venom. 



1 Stephens and Myers. Test-tube reactions between cobra poison and its antitoxin. Brit. Med. Jour., 

 1898, I, 630. 



