CHEMICAL EQUILIBRIA 



113 



sets of observations. Strangely enough there are 

 two observations for 72 = 0-675 which differ from 

 each other by not less than a third of the value, but 

 the mean value is in perfect accordance with the 

 calculated value. If we now take # = 025 as the 

 value of A, we find that the first addition of A 

 neutralizes 25 lethal doses (obs. 26), the second 24-5 

 (obs. 25), the third 23-5 (obs. 22), the fourth 182 

 (obs. 167), the fifth 57 (obs. 8-2), and the sixth only 



3 Quantity of Antitoxin 

 in equivalents 



Fig. 30. 



14 (obs. 06) lethal doses. This different action of 

 the different quantities of antitoxin is termed 

 Ehrlich's phenomenon. This peculiarity is just 

 what we might expect if the bond is rather weak, so 

 that a part of the compound is dissociated. The 

 progress of neutralization is represented by the 

 undermost curve in the diagram, Fig. 30. 



These figures were not the first calculated in the 

 said manner. There were some experiments on 

 tetanolysin, a poison produced by the lock-jaw 



