THE MICROBES OF WATER 



295 



It will be seen from the above analyses that the 

 number of microbes is greatly reduced by the 

 methods of nitration, etc., in use by the various 

 London water companies. The average reduction 

 in the number of developable microbes present in 

 the river waters before delivery by the companies 

 is from 96*2 to 99'1 per cent. 



Dr. Miquel 1 has also made periodical examina- 

 tions of the various waters in and around Paris. 

 Paris takes its supplies of water from the Seine and 

 Marne. There are three water-works belonging to 

 the former, and one belonging to the latter river. 

 During 1890 Miquel obtained the following results 

 with the Paris water supply : 



Annuaire de VObservatoire de Montsouris, 1887-91. 



