26 



IMMUNE SERA 



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 

 toxin formation a double action is always going 

 on that of toxin and toxon production, and that 

 of their decomposition. As was pointed out on 

 a previous page the poisons quickly change into 

 non-poisonous toxoids, and these substances are 

 still able to bind antitoxin. 



This is shown in the following " spectrum." 



Protoxoid 



10 20 30 40 50 



100 



Toxon 



150 160 



FIG. 3. 



Here we would obtain the following figures: 



x cc poison + f$$ antitoxin unit = o, i.e. abso- 

 lutely neutral. 



x cc poison + i{j-<|- = Toxon free. 



x cc poison + Mo = = Toxon free. 



X CG poison + Mf ---- Toxin free (i fatal dose.) 



x cc poison + iH = Toxin free (60 fatal doses. ) 



x cc poison + 5 e o\ = Toxin free (100 fatal doses.) 



