476 Profs. Percy Frankland and Marshall Ward. 



readily detected and confirmed on the plates from both broth-tubes 

 Ubs. 179 and 180. 



From these examinations it was evident, therefore, that the B. coll 

 -communis was still alive in the unsterilised Loch Katrine waters (kept 

 both tit winter and summer temperature) on July 21, 1893, or seventeen 

 days after infection ; the typhoid bacillus was also still alive in the similar 

 water kept at the winter temperature (6 8 (7.), whilst it was again, as 

 on the previous occasion (July 15, 1893), proved to be extinct in the same 

 water kept at the summer temperature of 19 C. 



3. Bacteriological Examination of the Infected Sterilised Loch 

 Katrine Waters. 



With the preceding results must now be compared the behaviour 

 of the typhoid bacillus and the B. coli communis in the Loch Katrine 

 water which had been previously sterilised by steam and by filtra- 

 tion through porous porcelain respectively. 



These infected sterile waters were, as before, intended to show 

 whether these bacilli are capable of multiplication or not in water of 

 this character when the disturbing influence of the simultaneous 

 presence of other micro-organisms is removed. 





