478 BACTERIOLOGY. 



producing the tissue-reaction which results in the for- 

 mation of the protecting substance. They likewise 

 isolated from the serum of immunized animals a pro- 

 teid that possesses the same powers as the serum itself, 

 viz., of affording immunity and curing the disease. 



Here, again, it appears that the processes of infection 

 and immunity are chemical in their nature, the active 

 poisons of the invading organisms — " the pneumo- 

 toxins" — being instrumental in producing the diseased 

 condition, while the antidotal or resisting body of the 

 tissues — "the anti-pneumotoxin " — is the agent by 

 which the poison is neutralized. 



Results in general analogous to those of G. and F. 

 Klemperer have also been obtained by Emmerich and 

 Fowitzky.^ 



In the light of these experiments the hypothesis ad- 

 vanced by Buchner, that the establishment of immunity 

 is to be explained by reactive changes in the integral 

 cells of the body, receives additional support, and when 

 we consider the observations of Bitter,^ who found that 

 in protective vaccinations against anthrax the vaccines 

 do not disseminate themselves through the body, as is 

 the case when the virulent organisms are introduced, 

 but remain at the point of inoculation, and from this 

 point produce, by the absorption of their chemical pro- 

 ducts, the systemic changes through which the animal 

 is protected against subsequent infection by the virulent 

 organisms, we feel justified in concluding that the Aveight 

 of evidence is strongly in favor of this view. 



The experiments of the past two or three years indi- 

 cate the probability of there being present in the blood 



1 Emmerich and Fowitzky : Miinoheuer med. Woohenschr., 1891, No. 32. 



2 Bitter : Zeltsohrlft fUr Hygiene, 1888, Bd. iv. 



