174 



MICRO-ORGANISMS IN WATER 



Bacterial Condition of Water filtered through a Gharfiherland filter 

 and kept at 35° and '2i'2P C. respectively (Freudenreich) 



Filters kept at a Temperature of 35° C. 

 Examination 1, after 2 days the water was sterile 



Filters Ti-ept at a Temperature of 22° C. 



Examination 1 after 7 days the water was sterile 

 2 



A filter kept at a temperature of between 15° and 

 18° C. yielded a sterile filtrate even after twenty-one 

 days. From these experiments it would appear that 

 certain bacteria are capable of growing through the 

 filter, and others not ; for whereas in some instances 



^ Freudenreich explains these discrepancies as due partly to differ- 

 ences in the character of the cylinders employed, and partly to differences 

 in the micro-organisms, present in the water at different times. 



