TOXINS AND ANTITOXINS. 37 



anti venom, which they filtered through a layer of 

 gelatin, under the supposition that, if the venom 

 and its anti venom were not chemically combined, 

 the former alone would be able to pass through 

 into the filtrate, because its molecules are so much 

 smaller. Martin and Cherry allowed the venom 

 and its antivenom to remain in contact for varying 

 periods before filtering. As the result of a series 

 of experiments carried out with this idea, they 

 have demonstrated that the filtrate obtained after 

 allowing a few minutes' contact between the two 

 substances, was decidedly toxic, while that obtained 

 after a contact of half an hour was absolutely non- 

 toxic. From this the authors conclude that the 

 antitoxin enters into chemical union with the 

 venom, but that the combination does not take 

 place immediately, and requires a certain length 

 of time for its accomplishment. 



Ehrlich and Knorr have demonstrated that the 

 neutralization is less rapid in dilute solutions than 

 in concentrated ones. 



Prof. Svante Arrhenius has completed our knowl- 

 edge regarding the mode of combination between 

 the toxins and the antitoxins, by demonstrating the 

 occurrence of limited reactions analogous to the 

 etherification of an alcohol by an acid, and in 

 such a manner that there always exists, in a mix- 

 ture of these two substances, a certain quantity of 

 free toxin and antitoxin. This is an important 



