IMMUNE SERA 



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 ZD 30 40 50 60 



100 



FIG. 3. 



Toxon 



150 160 



Here we would obtain the following figures: 



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



lutely neutral. 



x cc poison + if % = Toxon free. 



x cc poison + iJ = Toxon free. 



x cc poison + Mt = Toxin free (i fatal dose.) 



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



x cc poison + sVtf = Toxin free (100 fatal doses.) 



Now we come to the non-poisonous "prototoxoids" : 

 * cc + /cro- = Toxin free(ioo fatal doses.) 

 x cc + * 3 o<y = Toxin free (100 fatal doses.) 

 x cc + *i<r = Toxin free (100 fatal doses.) 

 We see here that after we have reduced the 



antitoxin to A<J n6 further increase of toxicity is 



brought about by any further reductions. Ehrlich 



