90 



MICRO-OKGANISMS IN WATER 



Biver Thames Water collected at Hampton] 



Number of Micro-organisms ohtainedfrom 1 c.c. of Water 



(Percy Frankland) 



Biver Lea Water collected at Chingford 



Number of Micro-organisms obtained from 1 c.c. of Water 



(Percy Frankland) 



Prom tlie above figures it will be seen that it is 

 during the summer months that these waters are purest 

 as regards micro-organisms, this being due to the fact 

 that during dry weather these rivers are mainly com- 

 posed of spring water, whilst at other seasons they 

 receive the washings of much cultivated land. 



In the following table Miquel ^ has stated for each 



^ Manuel ^pratique d"* Analyse bacteriologique des Eaux^ p. 132, 1891. 



