EXAMINATION OF WATER. 



137 



by making the fermentation-test (Fig. 48). Occasionally 

 other fermentative bacteria are found in water. 



FIG. 47. 



Esmarch apparatus for counting colonies in rolled tubes. (Abbott.) 

 FIG. 48. 



Flask for counting colonies of bacteria. 



The method usually employed for isolating the typhoid 

 bacillus from water is that of Pariette. He uses the follow- 

 ing solution : 



Phenol, 5 grams ; 



Hydrochloric acid, 4 " 



Distilled water, 100 c.c. 



