416 CHOLERA. 



changes in the small intestine. This animal had aborted a short time previ- 

 ously, and as its abdominal walls were very relaxed, Koch considered that 

 the intestinal peristalsis had been interfered with, and thus opportunity had 

 been afforded to the organisms of gaining a foothold and multiplying in the 

 intestine. He accordingly tried the effect of artificially interfering with the 

 intestinal peristalsis by injecting tincture of opium into the peritoneum (i c.c. 

 per 200 grm. weight), in addition to neutralising as before with the carbonate 

 of sodium solution. The result was remarkable, as thirty out of thirty-five 

 animals treated died with the same changes as in the single animal in the 

 previous series of experiments. The animals infected by this method show 

 signs of general prostration, their posterior extremities being especially 

 weakened ; the abdomen becomes tumid, respiration slow, heart's action weak, 

 and the surface cold. Death occurs after a few hours. Post 7uorteni the 

 small intestine is distended, its mucous membrane congested, and it contains 

 a colourless fluid with small flocculi and the cholera organisms in practically 

 pure cultures. These experiments, which have been repeatedly confirmed, 

 therefore demonstrated that the cholera organisms could, under certain con- 

 ditions, set up in animals a condition in some respects resembling cholera. 

 Koch, however, found that when the spirilla of Finkler and Prior, of Deneke, 

 and of Miller (vide infra) were employed by the same method, a certain, 

 though much smaller, proportion of the animals died from an intestinal infec- 

 tion. Though the changes in these cases were not so characteristic, they 

 were sufficient to prevent the results obtained with the cholera organism from 

 being used as a demonstration of the specific relation of the latter to the 

 disease. 



Within later years some additional facts of high interest have been 

 established with regard to choleraic infection of animals. For example, 

 Sabolotny found that in the marmot an intestinal infection readily takes place 

 by simple feeding with the organism, there resulting the usual intestinal 

 changes, sometimes with haemorrhagic peritonitis, the organisms, however, 

 being present also in the blood. It was found by Issaeff and Kolle that 

 young rabbits could be infected by merely neutralising the gastric secretion 

 with sodium carbonate, the use of opium being unnecessary ; but of special 

 interest is the fact, discovered by Metchnikoff, that in the case of young 

 rabbits shortly after birth a large proportion die of choleraic infection when 

 the organisms are simply introduced along with the milk, as may be done by 

 infecting the teats of the mother. Further, from these animals thus infected 

 the disease may be transmitted to others by a natural mode of infection. In 

 this affection of young rabbits many of the symptoms of cholera are present 

 great prostration, markedly subnormal temperature, sometimes anuria, and 

 occasionally slight cramps before death. Most frequently there is diarrhrea, 

 though sometimes this may be absent, the group of phenomena sometimes 

 corresponding, according to MetchnjkofF, with cholera sicca. The organisms 

 occur in large numbers in the intestine, and in some cases a few may be found 

 in the blood, and especially in the gall-bladder. Many of these experiments 

 were performed with the vibrio of Massowah, which is now admitted not to 

 be a true cholera organism, others with a cholera vibrio obtained from the 

 water of the Seine. 



