BACTERIAL CONTENTS OF VARIOUS WATERS 



91 



month the average of the observations made by him 

 during three years, 1887-90, of the water derived from 

 the Seine at Ivry, the Marne at St,-Maur, and the 

 Ourcq. 



Bacterial Contents of the Seine, the Marne, and the Ourcq (Miquel) 

 Nuviher of Micro -org anisms in 1 c.c. of Water 



Moutli 



January . 



February . 



March 



April . 



May . 



June . 



July . 



August 



September 



October 



November 



December . 



Average for the 



year 



OurccL 



143,370 



63,720 



47,780 



22,660 



29,340 



7,340 



7,730 



8,520 



8,070 



12,560 



135,700 



153,200 



53,330 



Prom this table it will be seen that the same phe- 

 nomenon is observable as in the case of the Thames and 

 the Lea, viz., that it is during the winter months that 

 the largest, and during the summer that the smallest, 

 number of bacteria are present in the water. 



In another series of experiments Miquel has col- 

 lected Seine water above and below Paris, and also at 

 St.-Denis after it has received the drainage from Paris. 

 He found that at Choisy, above the city, there were 

 800 in 1 c.c, at Percy, in the immediate vicinity of 

 Paris, 1,200, whilst at St.-Denis the numbers rose to 

 200,000 per c.c. 



An examination of the water supplied to Lyons 

 from the rivers Ehone and Saone has been made by G. 

 Eoux.^ The river Ehone water is filtered through sand 



^ Precis d' Analyse microhiologique des Eaux, p. 258. Paris, 1892. 



