580 BACTERIOLOGY. 



ished, this condition lasting for several days. In both 

 cases the cholera spirillum was obtained in pure cul- 

 ture from the dejecta. Another instance is reported 

 by Metschnikoff, in Paris, of a man who became 

 infected experimentally. In this case the algid stage 

 of cholera was produced, with complete suppression of 

 urine, cramps in the legs, contraction of the extrem- 

 ities, and collapse, the man's life being saved only with 

 difficulty. Finally, there is the case of Dr. Oergel, 

 of Hamburg, who accidentally, while experimenting on 

 a guinea-pig, had some of the infected peritoneal fluid 

 to squirt into his mouth. He was taken ill and died 

 a few days afterward of typical cholera, though at the 

 time of his death there was no cholera in the city. 

 These accidents and experiments would certainly seem 

 to prove conclusively the capability of pure cholera cul- 

 tures of producing the disease; and yet Strickler and 

 Hasterlick (Vienna, 1893) report negative results from 

 experiments on the human subject. This only goes to 

 show, however, that in cholera, like other infectious 

 diseases, there is an individual susceptibility. It is 

 also possible that the cultures used for experimentation 

 may have lost in virulence, as cholera cultures are so 

 liable to do when kept for any length of time. 



Cholera Toxin. Koch was the first to assume, as the 

 result of his investigations, that the severe symptoms 

 of the algid stage of cholera were due to the effects of 

 a toxin produced by the growth of the comma bacillus 

 in the intestines. 



In 1892, Pfeiffer published an account of his elabo- 

 rate researches relating to the cholera poison. He finds 

 that recent aerobic cultures of the cholera spirillum con- 

 tain a specific toxic substance which is fatal to guinea- 



