ACTIVE IMMUNIZATION 



Experiment. 



Results 



Second Fundamental Aggressin Test. 



(Its Property of Active Immunization.) 



Bail and his pupils believe that when bacteria invade a normal organ- 

 ism, it is the aggressin power of these bacteria which determines whether or 

 not, by their multiplication, disease will set in. If infection does take 

 place, it continues until the "aggressive" nature of the bacteria is curbed. 

 As there are some bacteria which on injection do not produce any disease, 

 Bail attributes this phenomenon of immunity to the missing " aggressive" 

 action of the respective bacteria. It is not merely the presence of bacteria 

 which is the criterion for the existence of disease; as long as they are void 

 of their " aggressive" property, they have actually become saprophytes. 



Accordingly, Bail believes that the bactericidal immunity is no true 

 immunity because it can be obtained by injection of dead micro-organisms 

 or by live bacteria in such minute doses that no specific symptoms are pro- 

 duced, i.e., no aggressins are produced within the body. "If the im- 

 munity lacks the "anti-aggressive" component, which alone governs the 

 existence of disease, one gains only an apparent immunity against the ex- 

 citing factor of the disease, but not against the disease itself" 



