THE SIGNIFICANCE OF B. COLI IN WATER. 83 



portions of water, tenths or hundredths of the cubic centi- 

 meter. It was first used by Brown (Brown, 1893) in 1892 

 for the New York State Board of Health, and its results 

 showed from 22 to 92 fecal bacteria per c.c. in the water 

 of the Hudson River at the Albany intake, and from 3 to 

 49 at various points in the Mohawk River between Amster- 

 dam and Schenectady. In some previous work at St. 

 Louis, the colon bacilli in the Mississippi River were found 

 to vary from 3 to 7 per c.c. 



Hammerl (Hammerl, 1897) used the presence of Bacillus 

 coli as a criterion of self-purification in the river Mur. 

 He considered, in spite of the position taken by Kruse, 

 that when a water contained large numbers of colon bacilli, 

 as well as an excess of bacteria in general, it might be 

 considered to be contaminated by human or animal excre- 

 ment. As, however, the organism would naturally be 

 present in large quantities of such a water as that of the 

 Mur, he used no enrichment process, but made plate cul- 

 tures direct; he denned the B. coli as a small bacillus, 

 non-motile or but feebly motile, growing rapidly at 37 C, 

 coaguf^ig milk and forming gas in sugar media. In 

 generaT, Hammerl failed to find colon bacilli in the 

 river by this method, except immediately below the 

 various towns situated upon it; at these points of pollution 

 he discovered a few colon colonies upon his plates, not 

 more than 4 to 6 per c.c. of the water. He concluded 

 that "the Bacterium coli, even when it is added to a 

 stream in great numbers, under certain circumstances 

 disappears very rapildy, so that it can no longer be detected 



