253 
CELE Hin, XIV, 
NEUTRALISATION OF VENOM BY ANTITOXIN. 
Iv is difficult, in the present state of our knowledge on the 
subject of toxins and antitoxins, to determine the precise nature 
of the reactions that are produced in the living organism as the 
result of serum injected for the purpose of preventing the toxic 
action of venom. 
I maintained, some years ago,' that the phenomenon in this 
case was a purely physiological one, which I considered to be 
proved by the fact that, if we mix im vitro, in determinate propor- 
tions, venom and antivenomous serum, and if we heat this mixture 
at 68° C. for half an hour, the injection of the heated mixture kills 
animals as if they were inoculated with venom alone, although 
with a considerable retardation. I concluded from this that, in all 
probability, antitoxic serum does not modify the toxin with which 
it is mixed, but that it confines itself to displaying a parallel and 
opposite action by preventing the noxious effects. I therefore 
supposed that no chemical combination is produced between these 
two substances, or, at least, that the combination effected is very 
unstable. 
My experiments were subsequently repeated by Martin and 
Cherry, who showed that the results as stated above were perfectly 
correct when the mixture of venom and antitoxin was heated less 
than ten minutes after it had been made, but that, if the heating 
' Annales de l'Institut Pasteur, 1895, No. 4. 
2 
* “The Nature of the Antagonism between Toxins and Antitoxins,” Proceed- 
ings of the Royal Society of London, vol. Ixiii., 1898, p. 420. 
