4i8 CHOLERA. 



in the algid stage, produce toxic phenomena and death, when injected 

 intravenously in rabbits. In this case also, nothing is known with 

 regard to the chemical nature of the toxic bodies. 



Experiments on the Human Subject. Experiments have 

 also been performed in the case of the human subject, both 

 intentionally and accidentally. In the course of Koch's 

 earlier work, one of the workers in his laboratory shortly 

 after leaving was seized with severe choleraic symptoms. 

 The stools were found to contain cholera spirilla in enor- 

 mous numbers. Recovery, however, took place. In this 

 case there was no other possible source of infection than 

 the cultures with which the man had been working, as no 

 cholera was present in Germany at the time. Within recent 

 years a considerable number of experiments have been per- 

 formed on the human subject, which certainly show that in 

 some cases more or less severe choleraic symptoms may 

 follow ingestion of pure cultures, whilst in others no effects 

 may result. The former was the case, for example, with 

 Emmerich and Pettenkofer, who made experiments on 

 themselves, the former especially becoming seriously ill. 

 In the case of both, diarrhoea was well marked, and numer- 

 ous cholera spirilla were present in the stools, though toxic 

 symptoms were proportionately less pronounced. Metchni- 

 koff also by experiments on himself and others obtained 

 results which convinced him of the specific relation of the 

 cholera spirillum to the disease. Lastly, the case of Dr. 

 Orgel in Hamburg may be noted, who contracted the 

 disease in the course of experiments with the cholera and 

 other spirilla, and died in spite of treatment. It is believed 

 that in sucking up some peritoneal fluid containing cholera 

 spirilla, a little entered his mouth and thus infection was 

 produced. This took place in September 1894 at a time 

 when there was no cholera in Germany. On the other 

 hand, in many cases the experimental ingestion of cholera 

 spirilla by the human subject has given negative results. 

 Still, as the result of observation of what takes place in a 

 cholera epidemic, it is the general opinion of authorities 

 that only a certain proportion of people are susceptible 



