222 



MICRO-ORGANISMS IN WATER 



aminecL The following experiments are selected, and 

 may be regarded as typical : 



Description 



River Thames as supplied by the Grand 



Junction Co. 

 River Thames as supplied by the 



Lambeth Co. 



The micro-organisms in these filtered waters multi- 

 ply, therefore, at 20 C. with far greater rapidity than 

 those in the unfiltered waters, which, as already pointed 

 out, have rather a tendency to become diminished, un- 

 less raised to the temperature of the incubator. The 

 following experiments again show the effect of placing 

 these filtered waters in the incubator for one night : 



Docriptioii 



River Thames as supplied by the Chelsea Co. 

 Ditto Lambeth Co. ..... 



Ditto Grand Junction Co. . 



Thus, at the temperature of the incubator, the mul- 

 tiplication which takes place during a single night is 

 enormous. 



Experiments were also made to ascertain the effect 

 of placing these filtered waters in a refrigerator for 

 a week, and the following examples illustrate this 

 point : 



