SPECIFICITY AND THERAPEUTIC VALUES OF ANTIVENINS 245 



Notwithstanding the pessimistic calculations of Martin and Lamb, Cal- 

 mette still adheres to his well-known optimistic views. He recommends the 

 injection of 10 c.c. of his antivenin when the symptoms are not yet manifest, 

 but 30 c.c. must be injected subcutaneously if the patient should come under 

 treatment after some delay or the snake should prove to be a cobra or a bun- 

 garus. Where symptoms of toxication are already present 10 to 20 c.c. of 

 the antivenin must be given intravenously. 



The third factor, which equally lessens the possibilities of the practical 

 application of antivenin treatment of snake poisoning, lies in the difficulty 

 of obtaining sufficient venom for immunizing large animals. In order to 

 promote the degree of immunity to a much higher standard than hitherto 

 accomplished, enormous quantities of venom would be required. To obtain 

 10 grams of dried cobra or daboia venom is by no means easy, but to accumu- 

 late many kilograms of such material appears to be impracticable. In fact 

 Lamb, who had every encouragement and support from the British govern- 

 ment and no doubt was best situated to undertake such work, confesses his 

 discouragement about the future of serum therapy for bites of Indian snakes. 



Again, in every case of snake bite we have to inject the specific antivenin 

 only, and no other. It is rather difficult to identify the nature of the snake 

 from the description of the victim. Even when the snake is identified, it may 

 happen that it is too small, though deadly, to furnish enough venom for pre- 

 paring its specific antivenin, and in such an instance there will be no available 

 antivenin. 



Although the future of antivenin therapy may appear hopelessly gloomy, 

 yet the problem of antivenins has its bright side. The circumstances which 

 control the amount of the venom injected by a snake are extremely variable. 

 Not every snake bite ends disastrously. Only those which occur under cir- 

 cumstances very favorable to the snake prove fatal. Under some conditions 

 only superficial scratches of the fangs may be inflicted. Between these two 

 extremes there must be a series of variations in which the excessive amounts 

 (beyond the dose which a man can bear) vary from a mere fraction of 0.001 gm. 

 up to those doses which would require 50 or 100 c.c. of the present antivenins 

 to neutralize and to prevent death. I conceive, therefore, that injections of 

 specific antivenins are of a great benefit in cases of snake-poisoning. It 

 would be necessary to employ the maximum practicable dose of antivenin in 

 every instance, no matter what quantity of the venom might have been injec- 

 ted by the snake. 



In America the future of antivenin therapy of snake bites is of a more 

 optimistic nature. The average fatality from the bite of the more common 

 American venomous snakes is extremely low and the occurrence of the accident 

 is comparatively rare. The collection of venoms is not as difficult as in India, 

 for Crotalus and Ancistrodon yield rather large amounts of venom. At the 

 Rockefeller Institute stronger antivenins for crotalus and moccasin venoms 

 are now being prepared. 



