ASIATIC CHOLERA. 



in a tank which contained the water supply of a neighbourhood 

 where cholera cases occurred; but commaihaped organisms are 

 frequently present in sewage-contaminated water. Korh> comma- 

 bacilli are aerobic, and their development is arrested by deprivation 

 of oxygt^ are destroyed by drying on a cover glass, but 



retain their vitality longer when dried on silk threads. Cultures 

 are sterilised by exposure for fifteen minui c., and l.v 



various antiseptic substances. 



FIG. 154. PCKE-CULMVATIOXS ix NUTRIENT GELATINE. , KOCH'S CHOUEKA 

 BACILLUS, twenty-four hours old. s FIKKLEE'S BACILLUS, twenty-four 



:- : .. 



METHODS .} STAINING THE COMMA-BACILLI OF KOCH. 



In cover-glass preparations they may be well stained in the ordinary 

 way, with an aqueous solution of methyl-riolet or fuchsine, or by the 

 rapid method, without passing through the flame (p. 85, Babes' method). 



A small quantity of the stools, or of the scraping of the intestinal 

 mucous membrane, is spread out on a glass slide and dried, then steeped 

 during some seconds in sublimate solution, or in osmic acid (I to 100). 

 It is then stained by immersion in fnchsine-aniline solutioi. 

 grammes of Bale fuchsine dissolved in a saturated aqueous solution of 

 aniline), washed, dried, and mounted in Canada balsam. 



