Report on the Bacteriology of Water. 



475 



3. The broth-tube, which had been rendered turbid in twenty-four 

 hours with coli-infected water, yielded plates containing numerous 

 depth and surface-expansion colonies, which were undoubtedly those 

 of the B. coli communis. 



Thus from these examinations it was apparent that on July 15, 1893, 

 or eleven days after infection, the Bacillus coli communis was still alive 

 in the unsterilised Loch Katrine ivater, as was also the typhoid bacillus 

 in similar water which had been kept at the winter temperature of 

 6 8 0., whilst in the water Icept at a summer temperature of 19 C. the 

 typhoid bacillus was no longer discoverable. 



Another examination was made of these uninfected and infected 

 unsterilised Loch Katrine waters on July 21, 1893, with the following 

 results : 



Examination of Unsterilised Loch Katrine Waters by Phenol Broth- 

 culture, 21.7.1893. 



The plate cultivations made from the above turbid broth-tubes 

 yielded the same results as those on July 15, 1893 ; thus no typhoid 

 colonies were obtained on the plates from broth-tube No. 177, whilst 

 they were easily discoverable and confirmed on the plates from 

 broth-tube No. 178 ; again the colonies of the B. coli communis were 



VOL. LVI, 2 K 



