30 IMMUNE SERA 



Bordet * believes that the neutralization of toxin 

 by antitoxin is an adsorption phenomenon, and 

 compares it with the process of dyeing. The 

 molecules of the toxin would " stain " more or less 

 deeply by the antitoxin molecule, and the com- 

 plexes that result in the various instances would 

 be less toxic in proportion as they contained more 

 antitoxin and less toxin. If a large piece of filter 

 paper is placed in a certain volume of sufficiently 

 diluted dye, it takes a uniform shade of intensity; 

 if, on the other hand, the same sized piece of paper 

 is cut in pieces and added in fragments, the first 

 pieces are stained deeply, and the last find no color 

 left. In the same way, on adding toxin to antitoxin 

 in divided doses, the last portions of the poison 

 cannot be neutralized, as the first are supersatu- 

 rated with antitoxin. When the entire mixture 

 is made at once, on the contrary, the antitoxin is 

 spread all over the toxin molecules and a complex 

 is obtained which contains an even proportion of 

 the antidote, and which, consequently, is not as 

 fatal as even a small dose of free toxin. The action 

 which Ehrlich therefore ascribes to toxons, Bordet 

 refers to toxin which is partially saturated with 

 antitoxin. Bordet also cites the researches of 

 Grassberger and Schattenfroh on the toxin of 

 symptomatic anthrax. The toxic fluid which these 



1 Bordet-Gay, Collected Studies in Immunity, Wiley & Sons, 

 1909. 



