22 BACTERIOLOGICAL EXAMINATION OF WATER. 



THE INFLUENCE OF THE CHEMICAL COMPOSITION OF A WATER 

 ON THE NUMBER OF MICRO-ORGANISMS. 



The relation of the chemical composition of a water supply 

 to the number of micro-organisms has been investigated by 

 many observers, especially in Germany. 



Proskauer examined the unfiltered water from Stralaw and 

 Tegel Works, and the filtered supply delivered to the houses. 

 His results were as follows : 



STRALAW. 



TEGEL. 



FILTERED WATER. 



G. Frank obtained similar results when examining the Spree 

 water from its entrance into Berlin up to Sacrow. From these 

 experiments it is apparent that there is no constant direct 



