4(58 BACTERIOLOGY. 



The failure to induce cholera in animals by feeding 

 or by injection of cultures into the stomach, was shown 

 by Nicati and Rietsch 1 to be due to the destructive 

 action of the acid gastric juice on the organisms. They 

 showed that if cultures of this organism were intro- 

 duced into the alimentary tract of certain animals in 

 such a manner that they would not be subjected to the 

 influence of the gastric juice, a pathological condition 

 closely simulating cholera as it occurs in man could be 

 produced. For this purpose the common bile-duct was 

 ligated, after which the cultures were injected directly 

 into the duodenum. Such interference with the flow 

 of bile lessens intestinal peristalsis, and thus permits 

 development of the organisms at the point at which 

 they are deposited that is, the portion of the intestine 

 having an alkaline reaction and beyond the influence of 

 the acid stomach-juice. 



By this method Nicati and Rietsch, Van Ermengem, 2 

 Koch, 3 and others were enabled to produce in the ani- 

 mals upon which they operated a condition that was, if 

 not identical, at all events very similar pathologically 

 to that seen in the intestines of subjects dead of the 

 disease. 



At a subsequent conference held in Berlin in 1885 

 Koch 4 described the following method, by means of 

 which he had been able to obtain a much greater de- 

 gree of constancy in all his efforts to produce cholera in 

 lower animals : bearing in mind the point made by 

 Nicati and Rietsch as to the effect produced by the acid 



1 Archiv. de Phys. norm, et path., 1885, t. vi., 3e ser. Comptes rendus, 

 xcix., p. 928. Kevue de Hygiene, 1885. Eevue de Medecine, 1885, v. 



2 Recherches sur le Microbe du Cholera Asiatique. Paris-Bruxelles, 

 1885, Bull, de 1'Acad. roy. de Med. de Belgique, xviii., 3e ser. 



3 Loc. cit. 4 Ibid., 1885. 



