ACTION OF CALMETTE S COBRA ANTIVENIN. 



203 



the neurotoxins as antigen, the antitoxin acting strongly on the neurotoxin 

 used as an antigen, and only very weakly upon the neurotoxin of a related 

 reptile. 



The recent experiment of Bang and Overton,* who found that the cobra 

 antitoxin had a protecting influence on tadpoles which were kept in a solution 

 of crotalus venom, to which the cobra antivenin had been added, seems to 

 point to a similar conclusion as that reached by ourselves. We must take into 

 consideration the fact that Bang and Overton observed the neutralizing effect 

 in experiments with crotalus venom, a substance rich in hemorrhagin; but per- 

 haps in this case also the protecting influence of the antivenin was mainly 

 directed against the neurotoxin in the crotalus venom. 



The following table gives a summary of our result : 



Fluids injected. 



Calmette serum 0.5 c.c. venom 0.15 mg 



Calmette serum 0.5 c.c. venom 0.3 mg 



Calmette serum 0.5 c.c, venom O.fi mg 



Calmette serum 0.5 c.c, venom 1.2 mg 



Calmette serum 0.5 c.c, venom 1.8 mg 



Calmette serum 0.5 c.c, venom 2.25 mg 



Calmette serum 0.75 c.c, venom 0.14 mg.; mixture 



kept at room temperature 



Calmette serum 0.75 c.c, venom 0.14 mg.; mixture 



kept at 37.5 C 



Calmette serum 0.5 c.c, venom 0.15 mg.; injected 



separately 



Horse serum 0.75 c.c; venom 0.14 mg 



Diphtheria antitoxin 0.5 c.c, venom 0.15 mg 



Rabbit serum 0.5 c.c; venom 0.15 mg 



Rabbit serum 1.0 c.c, venom 0.15 mg 



Rabbit serum 0.75 c.c; venom 0.1 mg.; 3 affected 



as soon as controls; 3 survived (1 control died, 



1 survived) 



Bang and Overton. Biochem. Zeitschrift, Bd. 34, p. 428, 1911. 

 tOnly one of these died. 



