164 BACTERIA. 



a condition of intoxication, which would account for the 

 death of those animals in which partially successful results 

 were first obtained. Further, it is evidently quite possible 

 that this intoxication rriay account for the very rapid deaths 

 which occur during certain epidemics, and also for the pre- 

 liminary diarrhoeas by which the intestine, in some cases at 

 any rate, is prepared for the reception and multiplication 

 of the cholera organism itself. It must, indeed, be looked 

 upon as one of the common causes of this diarrhoea. If 

 these facts be borne in mind it is possible, even without 

 analyzing the further experiments on animals, to understand 

 the immunity against cholera experienced byBochfontaine and 

 Klein, and the susceptibility of the doctor who was attending 

 the cholera course, whilst he was suffering from indigestion 

 and diarrhoea. It may also be understood how infection 

 occurs by milk and through water after what has been 

 described, and in accordance with these facts is the experience 

 of all those who have had to deal with cholera epidemics. 



Utilizing the experience gained by Koch in his experiments, Nicati 

 and Rietsch performed a series of operations, by means of which they 

 claimed they were able in a certain proportion of cases to produce 

 typical cholera symptoms. They introduced pure cultures of the commi 

 bacillus into the upper part of the intestinal canal, having previously 

 tied the bile duct ; but as Koch pointed out later they were successful in 

 producing true cholera, probably, only in those cases in which the intestine 

 was somewhat injured during the manipulation to which it was necessarily 

 subjected, and its peristaltic action interfered with, and it is very naturally 

 objected that death might be due not to the action of the cholera bacillus at 

 all but to this rough manipulation. The observers themselves believed that 

 it was the presence or absence of bile in the small intestine which determined 

 the success or failure of their experiments. 



In order to avoid the operation of opening into the 

 duodenum, Koch thought that the two great factors in 

 bringing about the destruction of the bacilli might be 

 thrown out of court, first by neutralizing the acid reaction 

 of the stomach by means of S c.c. of a 5 per cent, solution 

 of carbonate of soda ; and, secondly, by interfering with the 

 peristaltic action of the bowel. He found in test experi- 

 ments that the intestinal contents remained distinctly alka- 

 line for six hours after the introduction of such a solution. 

 But he also found that the organism still passed through the 

 stomach alive, and that it failed to produce any changes in 

 the small intestine, the food and the bacilli passing from the 



