viii CULTIVATION OF VIBRIOS 37 



(b) From the alcohol transfer it directly to filtered 

 aniline gentian-violet and allow it to stain for two to ten 

 minutes. 



(c) Einse the section in distilled water. 



(d) Now place it in Gram's iodine solution till it is 

 black (about two minutes). 



(e) Transfer it to absolute alcohol for a quarter to half 



a minute, and thence to 



0f* 

 (/) Acid alcohol (alcohol with 3 per cent hydrochloric 



acid) for not more than ten seconds. 



(g) Again wash it in alcohol until the section appears 

 colourless, or if previously stained with picrocarmine, until 

 the section again becomes red. 



(h) Clear it in xylol or turpentine and creasote. 

 (i) Transfer it to a slide with a cigarette-paper. 

 (k) Mount it in Canada balsam. 



Examine with low and high powers and -^ in. oil 

 immersion : the bacilli appear dark blue on a 

 yellowish or red background. 



Cholera 



Inoculate 



(1) a gelatine tube (stab), an agar-agar tube (streak), 

 and a broth tube with Vibrio cholerse Asiaticse ; 



(2) a gelatine tube (stab), an agar-agar tube (streak), 

 and a broth tube with Vibrio Finkler-Prior ; 



(3) a gelatine tube (stab), an agar-agar tube (streak), 

 and a broth tube with Vibrio Metchnicovi. 



