PHENOMENA FOLLOWING IMMUNIZATION 83 



thrown upon these phenomena by the efforts of hoth schools rapidly 

 led to a complete abandonment of those earlier theories of immunity 

 which had conceived the acquired resistance of animals against bac- 

 teria as a purely passive development in the body of conditions 

 unfavorable for bacterial gro ,vth. 



Among these earlier theories, now of historical interest only, are 

 the "Exhaustion Theory" of Pasteur and the "Ketention Theory' 7 of 

 Nencki, 13 Chauveau, and others. 



Pasteur's views, defended for a time also by Garre, held that the 

 growth of any given variety of bacteria in the animal body exhausted 

 certain specific nutritive substances necessary for this growth. Sub- 

 sequent lodgment in the same body was impossible owing to the 

 absence of proper nutrient material. It is interesting to note, as 

 Kolle 14 points out, that this theory is in principle very similar to 

 the "Atrepsie" idea of Ehrlich advanced in explanation of species 

 immunity to cancer. 



The hypotheses of Chauveau, of Nencki, and others were the 

 converse of those of Pasteur. They were based purely on inference, 

 assuming that conditions occurring in the test tube could be applied 

 also to those existing in the animal body. Baumann 15 had shown 

 that, among other things, phenol was produced as a result of bacterial 

 putrefaction. Nencki had noticed the inhibition of bacteria in 

 culture by the products of their own metabolism. Wernicke, 16 too, 

 had demonstrated the presence of phenol, phenylacetate, skatol, and 

 other aromatic compounds harmful to bacteria in putrefying mix- 

 tures. The reasoning which formulated the so-called "Retention The- 

 ory," therefore, was the following : Bacteria growing in the animal 

 body produce certain substances peculiar to their own metabolism, 

 which eventually lead to inhibition of their growth. By the retention 

 of these products the animal is rendered immune. Chauveau's adher- 

 ence to this theory was largely based on the fact that he had observed 

 immunity in the lambs born of Algerian ewes which had recovered 

 from anthrax shortly before or during parturition. He explained 

 this by a transference of the retention products from mother to off- 

 spring. As a matter of fact the observation could just as well have 

 been utilized as support for the Exhaustion Theory. 



Both the theory of "Exhaustion" as well as that of "Retention" 

 could not long withstand experimental criticism. .Theories which 

 were not so easily disproved and which have given rise to much in- 

 vestigation are the "Alkalinity Theory," first formulated by v. Beh- 



13 Nencki. Jour. f. prakt. Chem., May, 1879, cited from Sirotinin, 

 Zeitschr. f. Ilyg., Vol. 4, 1888. 



14 Kolle in "Kolle u. Wassermann Handbuch," 2d Ed., Vol. 1. 



15 Baumann. Zeitschr. f. physiol. Chem., Vol. 1. 



16 Wernicke. Virch. Archiv, Vol. 78. 



