308 BACTERIOLOGY. 



and soil ; immunity towards anthrax was ob- 

 tained in this way and the first harmless pro- 

 tective inoculation thereby effected. 



The conviction became general, moreover, 

 that many of the methods employed to sepa- 

 rate the " specific " poisons from the parasites 

 forming them destroyed or altered the so-called 

 " specific " poisons, and it was seen that 

 immunity was still obtained with the metabolic 

 products. In fact, if only the poisons them- 

 selves were introduced, immunity did not result, 

 as Roger and Charrin discovered before in work- 

 ing with Pyocyaneus, C. Frankel with diphthe- 

 ria, and Hueppe with chicken cholera. Guided 

 by these facts, Gamaleia and Hueppe, and 

 afterwards H. Buchner, were led to the discov- 

 ery that the " specific " poisonous substances 

 found outside the parasites in the culture fluids, 

 were not identical with the protective sub- 

 stances occurring in the disease germs or their 

 metabolic products. 



By these discoveries along the line of " speci- 

 fic " immunization it was established that: i, 

 Undergoing the disease, 2, Inoculation with 

 attenuated germs, 3, Inoculation with disease 

 germs which have become wholly impotent, 4, 

 Inoculation with saprophytes, and 5, Inocu- 

 lation with the metabolic products of the para- 

 site, can all confer immunity while ; 6, Inocu- 



