Report on the Bacteriology of Water. 



485 



Examinations of Coli-infected Sterilised Loch Katrine Waters by 

 Phenol Broth-culture. 



These examinations by phenol broth-culture substantiate the results 

 obtained by gelatine plates, and show that only a very small number 

 of the bacilli were still living in the waters on the later dates. Thus, 

 in the case of broth-tubes Nos. 199 and 200, it is evident that in No. 

 199, in which 2 c.c. of water were employed, at least one living B. coli 

 communis was introduced, for the broth-tube became turbid; whilst 

 in No. 200, in which only 1 c.c. of the same water was employed, no 

 living bacillus can have been introduced, as the broth-tube did not 

 become turbid. On referring to the table of gelatine plate examina- 

 tions (p. 483) it will be seen that on the same day (21.7.1893) in the 

 same water there was found only one B. coli communis colony per 

 1 c.c., so that it might easily happen that any particular 1 c.c. of the 

 water might not contain any bacillus, as was apparently the case in 

 the 1 c.c. of this water added to the phenol broth-tube No. 200. 



