1 62 BACTERIA. 



cholera, rice-water stools, great weakness, unquenchable 

 thirst, diminished excretion of water, except by the bowel, and 

 spasmodic contraction of the feet and toes. He was very 

 anxious to have this rice-water material examined for the 

 comma bacillus, and a quantity was despatched to Koch, 

 who was able to demonstrate in and cultivate from it, true 

 comma bacilli ; the patient recovered. There were no other 

 cases of cholera in Germany at the time, but the doctor had 

 been examining and making cultivations of the cholera 

 bacillus shortly before he was attacked, and there can be 

 little doubt that he had, through inattention to the rules of 

 the laboratory, in some way or other, ingested some of the 

 bacilli with which he had been working. 



The description of these cases of infection or non-infection 

 of individuals by cholera material introduced into the 

 alimentary canal, naturally opens up the way for an account 

 of the results obtained experimentally. 



Thiersch was the first to make experiments on animals 

 with cholera dejecta. He fed white mice with scraps of 

 filter paper, impregnated with decomposing cholera dejecta, 

 but he found that plain filter paper was equally efficacious 

 in causing the illness of the white mice. He was quickly 

 followed by Burdon Sanderson, who carried on a similar 

 series of experiments, and obtained much the same results. 

 Dr. Richards, of Goolando, also attempted to produce cholera 

 in pigs by feeding them with large quantities of cholera 

 material, but he found that the animals died in from fifteen 

 minutes to two and a half hours after the administration of 

 the poisonous material, and the contents of the intestine of 

 the first pig that died, when given to another, produced 

 absolutely no symptoms. It was argued from this that the 

 poison had not multiplied, but had been destroyed or ab- 

 sorbed, or rendered inactive in the stomach of the first host, 

 so that none was left to act on the second pig ; death in the 

 first case being produced by rapid intoxication through the 

 introduction of a large quantity of some active poison, and 

 not by a poison developed in the intestinal canal as in the 

 case of true cholera. This poison, whatever its nature, 

 had no effect on dogs. 



Following on these came a series of experiments by Koch, 

 who attempted to produce symptoms of cholera by feed- 

 ing and inoculating in various ways, mice, monkeys, cats, 



