Staining 4Q9 



to find spores in the cholera organism, and the nature of 

 the bodies described by Hiippe must be regarded as doubtful. 

 Staining. The cholera spirillum stains well with the 

 ordinary aqueous solutions of the anilin dyes, especially 

 fuchsin. At times the staining must be continued for from 

 five to ten minutes to secure homogeneity. The organism 

 does not stain by Gram's method. It may be colored and 

 examined while alive; thus, Cornil and Babes, in demon- 

 strating 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 



Fig. 14-8. Cover-glass preparation of a mucous floccule in Asiatic 

 cholera. X 650 (Vierordt). 



weak solution 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 of the slight stain they 

 take up, and because they still retain the power of vigor- 

 ous movement, which would be entirely lost if the specimen 

 were dried, stained, and mounted in the ordinary fashion." 



Isolation of the Organism. One of the best methods 

 of securing a pure culture of the cholera spirillum, and also 



