458 



Profs. Percy Franldand and Marshall Ward. 



Another examination by phenol hroth- culture was made of the 



typhoid-infected steam-sterilised Thames water about one month 



later, on 5.7.1893 and on 6.7.1893, and for the last time on 25.7.1893. 

 Thus 



Examination by Phenol Broth-culture. 



From the above it will be seen that even on 25.7.1893, when the 

 plate cultivations (see p. 452) were only yielding about twelve 

 colonies per c.c., and these colonies of a very feeble and degenerate 

 character, the phenol broth-cultures of 1 c.c. of the water still 

 became turbid in forty-eight hours, and thus revealed the presence of 

 living typhoid bacilli with the greatest facility. 



On the other hand, when the number of typhoid bacilli in the 

 water is small, it may very easily happen that a phenol broth tube 

 now and again may fail to go turbid (as in the case of Broth tubes 

 443 and 444, see table above), and it is very necessary, therefore, to 

 exercise great caution, and not to draw conclusions from a single 

 observation, but only after a number of repeated trials. 



The examinations by phenol broth-culture of these infected steam- 

 sterilised Thames waters thus entirely substantiate the results arrived at 



