Report on the Bacteriology of Water. 409 



labour, which is, however, well worth bestowing in consideration of 

 the very great importance attaching to the question at issue. 



FIRST SERIES OF EXPERIMENTS. 



The Vitality of the Typhoid Bacillus and of the Bacillus Coli 

 Communis in Thames Water. 



As already indicated above, I have endeavoured to make these ex- 

 periments as far as possible comparable with those previously con- 

 ducted by me on the B. anthracis and its spores recorded in the 

 Second Report. 



The Thames water was collected by me personally from the river, 

 close to the intake of the Grand Junction Waterworks, near Hamp- 

 ton, on May 4, 1893 ; this spot was selected as being in that region 

 of the river from which the supply for London is abstracted. 



This water was submitted to chemical analysis with the following 

 results : 



Results of Analysis expressed in Parts per 100,000. 



Total solid matters 26'SO ^ 



Organic carbon "1 , , , . f 0'247 



> by combustion < 

 nitrogen J I 0'038 



Organic nitrogen (by Kjeldahl 



method) 0'041 



Ammonia (free) 0'013 



,, (albuminoid) 0'016 The sample was turbid 



Oxygen consumed by organic )> and free from poison- 

 matter - 102 ous metals. 



Nitrogen as nitrates and nitrites. . 0'124 



Total combined nitrogen 0'173 



Chlorine T65 



Temporary hardness 13'8 



Permanent ,, 4'4 



Total , 18-2 _ 



The analysis shows that the water is chemically a typical sample 

 of Thames water as found in this part of the river at this season of 

 the year. 



In this series of experiments I proposed introducing the typhoid 

 and coli bacilli respectively into (a) Thames water in its natural and 

 unsterile condition; (6) Thames water sterilised by filtration through 

 porous porcelain ;* (c) Thames water sterilised by steam,\ and to com- 



* The Chamberland filter (see 2nd Eeport, ' Boy. Soc. Proc.,' vol. liii, p. 183) was 

 sterilised in the steamer on two successive days, 1 litres of the Thames water 

 being then passed through it immediately before infection. 



t 1500 c.c. of the Thames water were placed in the steamer for two hours on 

 each of three successive days. 



