54 



BA CTERIA 



RIVER THAMES WATER COLLECTED AT HAMPTON 



Number of Micro-organisms Obtained from i cc. of Water. 



Month. 



January. . . , 

 February . . 



March 



April 



May 



June 



July 



August. . . . 

 September. 

 October . . . 

 November . 

 December . 



1886. 



1887. 



1888. 



Again, another example : 



RIVER LEA WATER COLLECTED AT CHINGFORD 



Number of Micro-organisms Obtained from i cc. of Water. 



Month. 



January . . . 

 February. . 



March 



April 



May 



June 



July 



August. . . . 

 September. 

 October. . . 

 November. 

 December. . 



1886. 



1887. 



1888. 



*' During the summer months these waters are purest as 

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

 during dry weather these rivers are mainly composed of 

 spring water, whilst at other seasons they receive the wash- 

 ings of much cultivated land." — Frankland. 



