524 Profs. Percy Frankland and Marshall Ward. 



very large number of fluorescent liquefying colonies was found en 

 the plates, and in all the subsequent examinations of this water 

 numerous liquefying colonies were also present, thus clearly showing 

 that the diminution in the total number of colonies found in the 

 successive plates must have been in large measure due to the dying 

 off of the typhoid bacilli. 



Thus, whilst in the case of the simply typhoid- infected unsterilised 

 Thames water there is no evidence (see table, p. 521) of multiplication 

 of the contained water bacteria having taken place, in this typhoid- 

 infected steam-sterilised Thames water, to which a few water bacteria 

 had been added, there is evidence of abundant multiplication of these 

 water bacteria having occurred, and it becomes a matter of the 

 greatest importance to ascertain in which of these two waters the 

 typhoid bacilli (present in each case in approximately the same 

 numbers and having exactly the same origin and history) exhibited 

 the greater longevity. This question was determined by means of 

 the examinations by phenol broth-culture, the results of which are 

 recorded in the following tables : 



