104 Fermentation and Kindred Phenomena. 



the present century, since when there have been six visitations. 

 The first indications that cholera is caused by an organism 

 were the result of the researches of the French and German 

 commission sent to Alexandria in 1883 to investigate the disease. 

 Koch, a member of the German commission, discovered it, and 

 called it the " comma" bacillus, from its peculiar curved shape. 

 The bacillus is found in the intestine, but not in the blood ; it 

 can be cultivated on nutrient gelatine, and Koch has observed 

 that it readily multiplies in most articles of food, and even in 

 damp linen. It requires a fairly high temperature for favourable 

 development, but cold does not kill it. Koch also found the 

 organism in the stagnant waters of certain cholera-stricken 

 districts, and also in a tank, the water from which had apparently 

 produced the disease in several people who had used it for 

 drinking purposes. As soon as the bacilli disappeared from 

 the water, cholera cases ceased. 



I believe that there is still some doubt as to this organism 

 being the cause of the disease, as inoculation experiments have 

 only been of very doubtful success. It has been asserted that 

 cholera has been communicated experimentally to guinea-pigs ; 

 but others have maintained that these animals did not show the 

 typical symptoms. Bochefontaine, of Paris, swallowed pills 

 containing choleraic matter ; but although he felt unwell for 

 some days no serious symptoms arose. 



Many other diseases are believed to be due to organisms, and 

 of these I may enumerate the following : — 



Name of Disease. Nature of the Organism. 



Diptheria Micrococcus 



Erysipelas „ 



Pneumonia Bacteria 



Leprosy Bacillus 



Glanders 



