26 TOXINS AND ANTITOXINS. 



under certain conditions) which, introduced a cer- 

 tain time after the introduction of the poison, 

 will save the life of the animal. They have experi- 

 mented with diphtheria toxin, which we will study 

 later, and they have demonstrated that, if the 

 antitoxic serum be introduced immediately after 

 the toxin, a dose of antitoxin twice as large as 

 that of the toxin suffices to effect a cure. 



Eight hours after the administration of the toxin 

 the dose must be trebled, while after thirty-six hours 

 it is necessary to have recourse to a quantity of 

 antitoxin eight times as great. These experiments 

 show that the curative action of the antitoxin is 

 so much the less the longer the period of time 

 that has elapsed between the introduction of the toxin 

 and the antitoxin. This is because the toxin has 

 become so intimately attached to the tissues that 

 the antitoxin introduced has not the power to 

 destroy the combination. These facts have been 

 confirmed by Donitz * and by the classic experi- 

 ments of Decroly and Rousse.f 



This is not, however, the case with cold-blooded 

 animals, which, generally, are not affected by injec- 

 tions of poisonous toxins. Thus Metchnikoff J and 



* DONITZ: Ueber die Grenzen der Wirksamkeit des Diph- 

 theria Heilserums. Deutsche Med. Woch., No. 27, 1897. 



f DECROLY et ROUSSE: Arch. Int. de Pharmacodyn., in and 

 VI ; Masoin: Arch. Intern, de Pharmacodyn., n, 1903. 



J METCHNIKOFF: L'Immunite, Paris, 1902; MORGENROTH: 

 Zur Kenntniss des Tetanus des Frosches. Deutsche Med. Woch., 

 No. 35, 1898. 



