90 



MICRO-ORGANISMS IN WATER 



River Thames Water collected at Hampton] 



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



(Percy Frankland) 



1888 



92,000 



40,000 



66,000 



13,000 



1,900 



3,500 



1,070 



3,000 



1,740 



1,130 



11,700 



10,600 



Eiver Lea Water collected at Chingford 



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



(Percy Frankland) 



From the 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 dr}^ 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 1 has stated for each 



1 Manuel pratique d' Analyse bacteriologique des Eaux, p. 132, 1891. 



