

INOCULATION OF HUMAN SUBJECT. 391 



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 leav- 

 ing was seized with severe choleraic symptoms, attended 

 with watery evacuations, etc. The stools were found to 

 contain cholera spirilla in enormous numbers. Recovery, 

 however, took place. In this case there was no other con- 

 ceivable 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 performed 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 Petten- 

 kofer, who made experiments on themselves, the former 

 especially becoming seriously ill. In the case of both, 

 diarrhoea was well marked, and numerous cholera spirilla 

 were present in the stools, though toxic symptoms were 

 proportionately less pronounced. Metchnikoff also by ex- 

 periments 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 Ger- 

 many. 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 



