SPECIFICITY AND THERAPEUTIC VALUES OF ANTIVENINS 243 
tension becomes very high, but the subsequent administration, also intra- 
peritoneally, of an adequate amount of antivenin stops further distension and 
accelerates resorption of the sanguine exudate very promptly. The quantity 
of antivenin had to be increased the more the injection was delayed. 
The comparatively favorable results of experimental antivenin therapy 
against the crotalus and moccasin venoms are no doubt to be ascribed to the 
differences in the chief toxic principles of these American snake venoms and 
of the Indian cobra venoms. At least the absorption of the hemorrhagins, 
the chief toxins of the former, is much slower than the neurotoxins of the 
latter; hence there is more chance for the antivenin to act directly and in 
higher concentration. 
From these observations it would appear that antivenins, at least crotaline 
antivenins, possess excellent neutralizing quality. 
The second factor which affects the therapeutic value of antivenins is the 
conditions with which we have to deal in the practical cases of snake bite. 
This is an unknown factor, namely, the quantity of venom injected into the 
victim during the bite. It may happen that the snake injects the maximal 
quantity of its venom, or it may inject only a small quantity. It is the first 
hypothetical case that we ought to expect in practice. 
I have given the maximal quantities of venom per single bite for various 
kinds of venomous snakes in a separate topic and shall avoid repetition here, 
and take up only three representatives of subfamilies, Elapine, Crotaline, 
and Viperine, for the discussion (table 26). 
TABLE 26. 
Naja tripudians (cobra) yields about .............. 0.2 to 0.35 gm. (dried). 
Crotalus adamanteus (rattlesnake) yields about...... 0.2 too.3 gm. (dried). 
Daboia russellii (chain viper) yields about .......... 0.15 to 0.25 gm. (dried). 
Now the question arises as to the quantity of antivenins necessary to neu- 
tralize the above doses when mixed directly im vitro. Of course the quantity 
of antivenins depends upon the antitoxic units contained in them. 
According to Martin and Lamb‘ the cobra antivenin, prepared at the 
Pasteur Institute in India, requires 1 c.c. to neutralize o.cor gm. of dried 
cobra venom, while Calmette’s antivenin takes 2 c.c. for the same amount of 
venom. 
Of preparations of crotalus antivenins prepared by Flexner and Noguchi, 
0.5 c.c. neutralized o.cor gm. of dried crotalus venom. 
Of the daboia antivenin, prepared by Lamb, 1 c.c. is required to neutralize 
0.001 gm. of the dried venom. 
From these figures we can immediately calculate the amount of each anti- 
venin necessary to neutralize in vitro the maximal quantities of venoms liable 
to be injected by the respective snakes into their victims. 
But here comes another consideration, namely, the maximal amount of 
each venom which a man can resist. Calculated from the experiments made 
upon,monkeys the minimal lethal doses for cobra venom are placed by Lamb 
1C, J. Martin and Lamb. Snake bite. Allbutt System of Medicine, 1907, II, London. 
