120 



MICRO-ORGANISMS IN WATER 



Bacterial Contents of various Waters as supplied to London, 

 1885 (Percy Frankland) 



Colonies obtained from 1 c.c. of water 



The astonishing effect of sand-filtration, as practised 

 by the London water companies, is here shown for the 

 first time, and we find the first record of the actual re- 

 duction in the number of micro-organisms effected in 

 the following table : 



1885 



September 

 October 

 November 

 December 



Thames 



97-8 per cent. 

 96-5 

 98-9 



Lea 



98'5 per cent. 

 88.8 



At the request of the Local Government Board 

 regular bacteriological examinations were made by 

 one of us 1 of the water supplied to London by the 

 various water companies, and the results of these in- 

 vestigations for the years 1886, 1887 and 1888 are 

 recorded in the following tables, together with the per- 

 centage reduction in the number of micro-organisms 

 effected : 



1 Local Government Board Reports. Eyre and Spottiswoode. 



