CHAPTER XXIV. 
SPECIFICITY AND THERAPEUTIC VALUES OF ANTIVENINS. 
SPECIFICITY OF ANTIVENINS AS A WHOLE. 
Calmette at one time held that the neutralizing property of an antivenin 
is not quite specific, and that a number of immune serums produced by cer- 
tain plant toxalbumins or bacterial toxins can equally counteract the effects 
of snake venom, but the experimental evidences brought out by many inves- 
tigators now seem to contradict this view. ‘The investigations of Stephens 
and Myers seem conclusive on this point. They? first studied the effect of 
Calmette’s antivenin upon the hemolytic power of cobra venom and found 
that hemolysis can be completely prevented by adding enough antivenin, 
and that the relation holds good for a multiple of doses. This antihemo- 
lytic property was found to be specific to the antivenin. They also studied 
the relation between the antiheemolytic and the antitoxic powers of the anti- 
venin and found that with only 1 minimal lethal dose the neutralization went 
hand in hand for both principles, but with multiple doses a mixture hemo- 
lytically neutral still proved fatal. 
In a subsequent paper? the same authors extended their study on the 
specific protective action of antivenin, the anticlotting power of cobra venom 
being used as a test-reaction. ‘They arrived at the same conclusions as in 
their previous experiments on hemolysis, namely, that the anticlotting power 
of cobra venom can be neutralized by the antivenin and that this neutraliza- 
tion is specific. ‘They state that the neutralization of the anticlotting and that 
of the toxic power of cobra venom run parallel as long as only one minimal 
lethal dose is used, but this ratio does not hold good in multiple doses of 
venom in regard to its lethal effects in vivo. 
SPECIFICITY OF ANTIVENINS DUE TO DIFFERENCES IN THE CHARACTER- 
ISTIC TOXIC PRINCIPLES OF THE VENOM OF EACH SPECIES. 
The fatal effects of various kinds of snake venoms are by no means due 
to one toxic principle, but are produced by different sets of toxins which vary 
according to the kind of venom. Thus in the venoms of Naja, Bungarus, 
and all of the Hydrophiine death is produced through the neurotoxins present 
in these venoms in dominating proportions. On the other hand, the venoms 
of Viperine, namely, those of Daboia or Echis, cause instantaneous death by 
1 Stephens sei Myers. ‘Test-tube reactions between cobra poison and its antitoxin. Brit. Med. Jour., 
1898, I, 620. 
2 Stephens and Myers. The action of cobra poison on the blood, a contribution to the study of passive 
immunity. Jour. of Path. and Bacter., 1898, V, 279. 
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