VENOM HAMOLYSIS 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 imira 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. Hmolysis 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 hemolytic 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 hemolysis. 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 hemolytic 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 hemolysin 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 hemotoxic substances was employed 
first by Ehrlich in his famous studies on ricin and abrin and their antiserums. 
Of hemolytic substances, Madsen, under Ehrlich, introduced a colorimetric 
measurement for determining the quantity of liberated hemoglobin 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 hemolytic strength of snake venom 
was first employed by Myers and Stephens‘ in their study on cobra venom. 
1 Stephens fad Myers. ‘Test-tube reactions between cobra poison and its antitoxin. Brit. Med. Jour., 
1898, I, 620. 
