SPIRILLUM OF ASIATIC CHOLERA. 377 



The failure to induce cholera in animals by feeding, 

 or by injection of cultures into the stomach, was shown 

 by Nicati and Rietsch' to be due to the destructive 

 action of the acid gastric juice on the bacilli. 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 condition pathologically 

 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 the 

 development of the bacilli at the point at which they 

 are deposited — that is, the portion of the intestine hav- 

 ing an alkaline reaction and beyond the influence of the 

 acid stomach-juice. 



By this method Nicati and Rietsch, Van Ermengem,^ 

 Koch,' 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* described the following method by means of 

 which he had been able to obtain a relatively high 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 

 reaction of the gastric juice, this reaction was first to be 



1 Arohiv. de Phys. norm, et path., 1885, xvii., 3e s6r., t. vi. Compt.-rend., 

 xcix. p. 928. Kev. de HygWne, 1885. Rev. de M«d , 1885, v. 



2 " Eeoherehes sur le Microbe du ChoWra Asiatique," Paris-Bruxelles, 1885. 

 Bull, de I'Aead. roy. de MSd. de Belglque, Seser., xviil. 



3 Loo. cit. * Loo. cit., 1885. 



