Report on the Bacteriology of Water. 



507 



This porcelain-filtered deep well water, to which the tliree drops of 

 msterile deep well water were thus added on 11.11.1893, was ex- 

 lined by plate cultivation on 14.11.1893, or three days after the 

 lition, and was then found to contain 10,462 bacteria per 1 c.c. ; it was 

 jain examined on 23.11.1893, or twelve days after the addition, and then 

 contained 603,900 bacteria. It is obvious, therefore, that in this same 

 water in ivhich the typhoid bacilli were destroyed with such remarkable 

 rapidity, some at any rate of the common water bacteria present in the 

 unsterile deep well water were able to multiply both to an enormous extent 

 and with wonderful celerity. This result dismisses, in my opinion, the 

 last lurking suspicion which might still remain of any antiseptic 

 substance having accidentally gained access to the water in the 

 process of filtration through these porous cylinders. 



VOL. LVI. 



2 H 



