Rn acelin 
SPIRILLUM CHOLERZ ASIATICZ. 579 
weakened by the fact that experiments made with 
some other bacteria—viz., those isolated by Finkler and 
Prior, Deneke, and Miller, and morphologically similar 
to the comma bacillus of Koch—occasionally pro- 
duced death when introduced in the same way into 
the small intestines of guinea-pigs; but while only 
twelve out of fifty-one animals died when injected 
with cultures of these last-mentioned bacteria, in the 
cholera experiments there was 90 per cent. of deaths, 
and when larger doses were administered all of the 
animals died. Control experiments made with many 
other bacteria gave negative results. Intraperitoneal 
injections of larger quantities of pure cholera cultures 
also often produce death in rabbits and mice. 
There are several cases on record which furnish the 
most satisfactory evidence that the cholera bacillus is 
able to produce the disease in man. In 1884, a student 
in Koch’s laboratory in Berlin, who was taking a course 
on cholera, became ill with a severe attack.of cholera. 
At that time there was no cholera in Germany, and the 
infection could not have been produced in any other 
way than through the cholera cultures which were heing 
used for the instruction of students. In 1892, Petten- 
kofer and Emmerich experimented on themselves by 
swallowing small quantities of fresh cholera cultures 
obtained from Hamburg. Pettenkofer was affected 
with a mild attack of cholerine or severe diarrhea, from 
which he recovered in a few days without any serious 
effects; but Emmerich became very ill. On the night 
following the infection he was attacked by frequent evac- 
uations of the characteristic rice-water type, cramps, 
tympanitis, and great prostration. His voice became 
hoarse, and the secretion of urine was somewhat dimin- 
