134 



MICRO-ORGANISMS IN WATER 



West Middlesex Waterworks, Barnes, August 12, 1892 



No. of 

 Filter Bed 



No. 1 . 

 No. 11 

 No. 2 . 

 No. 3 . 

 No. 9 . 

 No. 7 . 

 No. 10 

 No. 8 . 



Filter Bed 



Filtered Water 



Age of Filter 

 Bed in days 



. 14 . 



. 33 . 



. 62 . 



. 36 . 



3 . 



. 45 . 

 10 



No. of Colonies 

 from 1 c.c. 

 of Water 



. 98 



. 65 



. 25 



. 16 



. 27 



. 17 



. 22 

 18 



No. 1 

 No. 11 

 No. 2 

 No. 9 



No. of Colonies 

 from 1 c.c 

 of Water 



. 288 



. 691 



. 447 



308 



West Middlesex Waterworks, Barnes, Oct. 3, 1892 

 Filtered Water 



Age of Filter 

 Bed in davs 



No. of Colonies. 



from 1 c.c. 



of Water 



No. of Filter Bed 



Nos. 1 and 11 (princi- 

 pally from No. 11) 

 No. 2 . 

 No. 3 . 

 No. 5 . 

 No. 8 . 

 No. 9 



Unaltered Water 



Unfiltered Thames Water from Hampton . 1,437 



Uiifiltered Thames Water which had only 



passed through one subsiding reservoir . 318 



Ditto, which had passed through two sub- 

 siding reservoirs 177 



Thus in the experiments made at these works on 

 August 12, 1892, the unfiltered and filtered waters of 

 ei ( i>'ht filter beds were submitted to examination. 



The number of bacteria in the unfiltered water 

 varied from 851 to 271, and averaged 482 in one cubic 



