BACTERIAL ACTIVITY 179 



that lecithin (a highly complex fat found in the nervous 

 system, and to a less extent in bile) has the property of 

 activating the haemolytic substance in cobra venom. This 

 is very important, since it points to a definite chemical 

 combination, leading to the formation of a toxin from two 

 non-toxic bodies, and is in line with the observed for- 

 mation in diphtheria of an antitoxin, which has many of 

 the characters of a chemical antidote. 



