ANTITOXINS 



Here we would obtain the following figures: 



2 7 



# cc poison -f 

 lutely neutral. 



# cc poison + 



# cc poison + 



# cc poison -f 



oo poison + 



oc cc poison + 



antitoxin unit = o, i.e. abso- 



= Toxon free. 

 = Toxon free. 



= Toxin free (i fatal dose.) 

 - Toxin free (60 fatal doses. ) 

 = Toxin free (100 fatal doses.) 

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

 # cc + inm = Toxin free(ioo fatal doses.) 

 # cc + *oo = Toxin free (100 fatal doses.) 

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

 We see here that after we have reduced the 

 antitoxin to ^ no further increase of toxicity is 

 brought about by any further reductions. Ehrlich 

 calls these toxoids " prototoxoids " because they 

 have such a high affinity for the antitoxin. But 

 there are apparently still other toxoids, as is shown 

 by the following spectrum: 



Protoxoid 



Syntoxoid 



Toxon 



' 100 ' 10 ' '200 



FIG. 4. 



Here we would obtain values as follows: 

 x cc poison -f- f $% = o, i.e. absolutely neutral. 

 x ce poison -f iol = Toxon. 



