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 aérobic cultures of the cholera spirillum con- 
tain a specific toxic substance which is fatal to guinea- 
