ANTITOXINS 35 



# cc poison 4- *t>& = Free toxon. 



# cc poison + %%% = Free toxon. 



That is to say, if the proportion of antitoxin added 

 was Mtf of the amount required for complete 

 neutralization, it would be found that the poison 

 thus uncombined was much less, and differently 

 toxic than a corresponding amount of the original 

 toxin. It was found that these fractions possessed 

 a rather constant though low degree of toxicity 

 with characteristic action. This consisted in the 

 production of some local oedema, followed by a 

 long incubation period, and finally the develop- 

 ment of cachexia and paralysis. Ehrlich believes 

 that this action is due to a separate poison excreted 

 by the diphtheria bacillus which he calls a toxon. 



If we continue with the above poison we shall 

 obtain these values: 



x cc poison + i&ftj- = Toxin action (i fatal dose). 



of 6 poison + /A =30 fatal doses. 



x cc poison + sW = 90 fatal doses, etc. 



That is to say, if we add only $& units antitoxin ; 

 i.e. T^TF unit less than in the i&& mixture, we find 

 that one fatal dose is set free. This relation would 

 exist right to the end. The fact that in this experi- 

 ment the toxins are liberated after the toxons, 

 shows that the toxons have less affinity for the anti- 

 toxin than have the toxins. 



As a matter of fact, however, conditions are prob- 

 ably never as simple as this. In the process of 



