Report on the Bacteriology of Water. 473 



munis in twenty-four hours, the uninfected and typhoid -infected 

 waters in forty-eight hoars. 



Of the plate cultivations prepared from these turbid broth-tubes, 

 it need only be stated that the plates from the tubes which had gone 

 turbid with typhoid-infected water, yielded characteristic typhoid 

 colonies which satisfied all the several confirmatory tests ; similarly 

 the plates prepared from those broth-tubes which had been rendered 

 turbid by coli-infected water, yielded the characteristic colonies of the 

 B. coli communis, and also satisfied the various confirmatory tests. 

 On the other hand, those phenol broth-tubes which had become turbid 

 through the uninfected water, yielded colonies on the plates which 

 were small in the depth, and formed small pin-heads on the surface 

 of the gelatine, but did not give rise to the characteristic expan- 

 sions, whilst on transferring these to potatoes, strong, highly -raised, 

 greyish growths, much more conspicuous than those of typhoid, were 

 obtained. 



Thus on July 8, 1893, four days after infection, both the typhoid 

 bacillus and the B. coli communis were proved to be still alive in the 

 unsterilised Loch Katrine water. 



The second examination by phenol broth-culture was made on 

 July 15, 1893, or eleven days after infection, with the following 

 results : 



