Report on the Bacteriology of Water. 455 



From the above table it will be seen that the B. coli communis 

 presents a great contrast to the typhoid bacillus in respect of its 

 behaviour in this steam-sterilised Thames water. Thus, at the com- 

 mencement of the experiment, both bacilli were present in about the 

 same numbers, the typhoid-infected water containing 74,000, and 

 the coli-infected water, 69,000 bacilli per 1 c.c. respectively, but 

 whilst the subsequent numbers found in the typhoid-infected waters 

 were invariably less than this initial number in the case of the coli- 

 infected waters, the initial number was subsequently very greatly 

 exceeded, the observed multiplication being greatest in the water 

 kept at a summer temperature. This multiplication was afterwards 

 followed by a corresponding decline, but even at the end of the 

 seventy-five days over which the observations were extended, the 

 number of the coli bacilli greatly exceeded that of the typhoid bacilli. 

 It is, moreover, worthy of remark that the coli-infected water kept at 

 19 C., in which the most extensive multiplication took place, ulti- 

 mately contained a smaller number of coli bacilli than the water 

 maintained at 6 C., in which the multiplication had been less con- 

 siderable. 



The above results, obtained by the gelatine plate cultivation of the 

 typhoid and coli-infected steam-sterilised Thames waters, were re- 

 peatedly confirmed and supplemented by the method of phenol 

 broth-culture, thus : 



