116 CHEMICAL EQUILIBRIA 



of added acid over this point of first acid action. 

 The smaller angle between the line marked Acid 

 and the ^r-axis indicates that acids have about half 

 as great haemolytic power as bases. 



The neutralization of cobra lysin (poison from 

 the cobra) by its antibody, the so-called antivenin, 

 behaves in nearly the same manner (see Fig. 31, 

 upper line). But there is really a small degree of 



75 



o 

 52 

 o 



Q. 



I' 5 



75 

 ©•25 



Fig. 31. 



dissociation, for when an equivalent quantity of 

 antivenin is added to the venom still 3-3 per cent 

 of its toxicity remains, according to the observations 

 of Madsen and Noguchi, from which we may 

 calculate the dissociation constant to be K = 00014 

 or the seventh part of that for diphtheria poison. 

 Another snake venom from the water- moccasin 

 (Ancistrodon piscivorus) gives the value K = o-oo6, 

 and that from Crotalus only K = 00006. Their 



