572 



Asiatic Cholera 



Babes, in demonstrating it in the rice-water discharges, " spread out 

 one of the white mucous fragments upon a glass slide and allow 

 it to dry partially; a small quantity of an exceedingly weak solu- 

 tion of methyl violet in distilled water is then applied to it, and it is 

 flattened out by pressing down a cover-glass, over which is placed a 

 fragment of filter-paper, which absorbs any excess of fluid at the 

 margin of the cover-glass. The characteristics of comma bacilli 

 so prepared and examined with an oil-immersion lens ( X 700-800) 

 are readily made out because, though they take up enough stain 

 to color them, they still retain the power of vigorous movement, 

 which would be entirely lost if the specimen were dried, stained, and 

 mounted in the ordinary fashion." 



Fig. 238. Spirillum of Asiatic cholera; colonies two days old upon a gelatin 

 plate. X 35 (Heim). 



Isolation of the Organism. One of the best methods of securing 

 a pure culture of the cholera spirillum, and also of making a bacterio- 

 logic diagnosis of the disease in a suspected case, is probably that 

 of Schottelius. v 



A small quantity of the fecal matter is mixed with bouillon and stood in an 

 incubating oven for twenty-four hours. If the cholera spirilla are present they 

 will grow most rapidly at the surface of the liquid where the supply of air is good. 

 A pellicle will be formed, a drop from which, diluted in melted gelatin and poured 

 upon plates, will show typical colonies. 



Cultivation. The cholera organism is easily cultivated, and 

 grows luxuriantly upon the usual laboratory media. 



Colonies. The colonies grown upon gelatin plates are character- 

 istic and appear in the lower strata of the gelatin as small white 



