Report on the Bacteriology of Water. 



351 



K. 



After the six and a half hours' exposure two plates were made from 

 each flask. The two from F 7 (exposed) gave 93 and 31 per c.c. ; 

 total, 124 ; mean, 62 colonies per c.c. ; while those from F 8 (covered) 

 in the same period of incubation, viz., four days, gave 2190 and 2130 ; 

 total, 4320; mean, 2160 per c.c. 



Here again, therefore, the direct sunshine has a decided bactericidal 

 effect, as is clear from details in the following Table L : 



