VIL] PRODUCTION OF CHOLERA. 123 



ground ; from a diseased intestine they had been originally 

 derived. 



Koch repeated (Deutsch. med. Woch. 45, 1884) these 

 experiments of Nicati and Rietsch on dogs, without pre- 

 viously ligaturing the bile-buct. The fluid, a fraction of a 

 drop of a cultivation of comma-bacilli greatly diluted, was 

 injected into the duodenum, of course after opening the 

 abdominal cavity. " With few exceptions the animals so 

 experimented upon died after one and a half to three days. 

 The mucous membrane of the small intestine was reddened, 

 its contents watery, colourless, or slightly reddish, and at 

 the same time flakey. In the intestinal contents the comma- 

 bacilli were present in pure cultivation and in enormous 

 numbers. We have then here the same appearances as in 

 the cholera intestine in acute cases." To these experiments 

 I have to apply exactly the same criticism as I applied above 

 to those of Nicati and Rietsch. There is absolutely no 

 guarantee that the peritoneum and bowels of an animal 

 under such an experiment, leaving out the comma-bacilli, 

 would not become inflamed, and in this state the comma- 

 bacilli would readily and copiously multiply. From some 

 experiments made later by Koch, and hereafter to be 

 described, this assumption will appear very feasible. 



I recommend to the notice of van Ermengem, and particu- 

 larly to Mr. Watson Cheyne and Dr. Workman, the following 

 statements on those points made by Koch himself, after a large 

 number of experiments. These gentlemen thought it quite 

 unwarranted and thoughtless on my part to accuse the 

 operation as having anything to do with the result of the 

 experiments. Here is the passage of Koch's that I refer to, 

 as given in his address to the Second Conference on Cholera 

 held in Berlin, May 1885 : l 



1 Brit. McL Journ. Jan. 9, 1886, p. 62. 



