LESSON V 



Examination of Water (concluded] Examination of Water for the 

 Vibrio Choleras Asiaticse Peptone Method Gruber's Method 

 Agar-Agar Plate Method Gelatine Plate Method. 



II. Qualitative Examination of Water (concluded) 



B. EXAMINATION OF WATER FOR THE VIBRIO CHOLERA 

 ASIATICS. 



A sample of water is supplied containing cholera vibrios 

 (500 cc. of distilled water containing four broth tubes 

 of cholera vibrios). 



I. Peptone method. 



(1) To separate the vibrios, fill four small sterilised 

 flasks with 50 cc. of 2 per cent peptone solution each. 



(2) To these add respectively 50 cc., 40 cc., 25 cc., and 

 10 cc. of the suspected water, and place the flasks in the 

 warm incubator till next morning. 



(3) Now examine the surface of the culture fluid for 

 vibrios by means of cover- glass films, which should be 

 stained with carbol fuchsine or aniline gentian-violet (vide 

 p. 40). 



