XVI VENOMOUS SNAKES AND THE PHENOMENA OF THEIR VENOMS 



The introduction of snake venom into the domain of immunity has been 

 quite fruitful in obtaining various facts which served to increase our knowl- 

 edge of the nature of immunization in general. On its practical side we all 

 know that Calmette was the first to recommend his antivenin for the treat- 

 ment of snake poisoning, and, despite much protest and dispute as to its 

 value as a therapeutic, it has no doubt saved many victims from death. This 

 assertion requires no advocate, because the antitoxic property of the anti- 

 venomous serum has long been established on the purely experimental basis, 

 and this alone is enough to encourage the use of the antivenin in as large doses 

 as practicable in all cases of snake bites. 



Many lives must have perished through the minute excess of venom beyond 

 the limit of human toleration, whereas the removal of that excess by the injec- 

 tion of a few vials of antivenin would have spared them from the grip of 

 death. There are to-day at least several different specific antivenins that can 

 be employed in combating snake bites. These are of comparatively feeble 

 strength, yet we may reasonably expect some benefit from these preparations. 



I do not believe that the limit of antitoxic units attainable by these immune 

 serums has been reached, but I am convinced that in the future much more 

 potential antivenins will be obtained through the employment of various 

 methods and improvements in the modes of immunization. 



The importance of a thorough consideration of the specificity of anti- 

 venomous serums was recognized in the earlier work of C. J. Martin and the 

 later investigations of George Lamb and also of the present writer. While 

 Calmette once erred as to the specificity of antivenin although not without 

 possible grounds for his assumption C. J. Martin keenly observed that 

 the action of antivenin is specific in the sense that the physiological actions 

 of the venom of different species of snake are the work of different constitu- 

 ents of each specimen; hence the antivenin capable of counteracting the 

 lethal principle A fails or may fail against the lethal principle B or C of other 

 venoms. Here Martin openly regards the venom as a polytropic poison and 

 sees the necessity of securing a polytropic antitoxin. This line of thought is 

 in perfect harmony with the early views of Mitchell and Reichert and the 

 later treatise of Flexner and Noguchi. 



The question of specificity did not, however, remain long without another 

 and still more urgent modification the question of individual specificity. 

 Lamb and Noguchi investigated another problem, as to whether or not the 

 individual toxic constituents of the venoms belonging to the different species 

 are identical. That the physiological and pathological effects do not reliably 

 indicate the principles that produce them, hence disclose no identity of the 

 active agents, is well understood. But, when we come to deal with such 

 substances as snake venoms so closely related to each other both in action 

 and origin there is but little reason for one to doubt their complete identity. 

 It is most extraordinary that the haemolytic or neurotoxic or haemorrhagic 

 constituents of one kind of snake venom should differ from the similar con- 

 stituents of another kind; yet this was found to be the case. In its infinite 



