vii.] PRODUCTION OF CHOLERA. 133 



jured through the stomach; but they had not set up any 

 disease in the animals." Similar experiments were then 

 made on eight other guinea-pigs. These animals also re- 

 mained quite healthy. Finally four guinea-pigs were similarly 

 experimented upon (5 ccm. of solution of sodium carbon- 

 ate, then 10 ccm. of cultivation of the comma-bacilli in 

 meat-infusion) ; three remained well, the fourth appeared ill 

 next day, looked shaggy and did not eat ; on the following 

 day it was very ill ; paralytic weakness of the posterior ex- 

 tremities came on, the respiration was weak and slow, the 

 head and extremities were cold, and the animal died in this 

 condition. On post-mortem examination the small intestine 

 was markedly reddened and full of a flakey, watery, colour- 

 less fluid. The stomach and caecum contained a large 

 quantity of fluid. "The examination with the microscope 

 and with gelatine-plates showed that the contents of the 

 small intestine contained a pure cultivation of the choleraic 

 comma-bacilli." " That this one animal only should have 

 died, out of a series of nineteen uniformly experimented upon, 

 suggested some peculiar condition that had obtained in 

 this one animal and as a matter of fact on examination it 

 was ascertained that this animal had aborted immediately 

 before the injection, and on post-mortem examination it 

 was found that the abdominal walls were very flaccid and 

 the uterus still greatly enlarged. This led me to the idea 

 that either the abortion per se, or perhaps its unknown cause, 

 had acted on the other abdominal organs, more especially 

 on the small intestine, in such a way as to produce a tem- 

 porary relaxation with arrest of peristaltic movement ; and 

 thus had rendered it possible for the comma-bacilli to remain 

 longer and gain a footing in the intestine." This conclusion 

 appeared to Koch justifiable, inasmuch as by direct experi- 

 ment he thought he had proved that the contents of the 



