MICROSPIRA COMMA 533 



Nicati and Rietsch^ to be due to the destructive action of 

 the acid gastric juice on the organisms. They showed that 

 if cultures of this organism were introduced into the alimen- 

 tary 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 inter- 

 ference 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,^ 

 Koch,^ and others were enabled to produce in the animals 

 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 much greater degree of constancy 

 in 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 neutralized by injecting through 

 a soft catheter passed down the esophagus into the stomach 

 5 c.c. of a 5 per cent, solution of sodium carbonate. Ten 



' Arohiv de Phys. norm, et path., 1885, t. vi. 3e s^r. Comptes rendus,_ 

 xcix, p. 928; Revue de Hygitoe, 1885; Revue de Medecine, 1885, v. 



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

 1885; Bull, de I'Acad. roy. de Med. de Belgique, xviii, 3e sfir. 



3 Loc. cit. ' Loo. oit. 



