122 Elements of Water Bacteriology. 



The practical results of the application of the colon 

 test from this standpoint have proved of the highest value. 

 As originally outlined by Dr. Smith, it consisted in the 

 inoculation of a series of dextrose tubes with small por- 

 tions 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 

 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 (Ha'mmerl, 1897) used the presence of Bacil- 

 lus 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 excrement. 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 cultures direct; he defined the B. coli as a 

 small bacillus, non-motile or but feebly motile, growing 

 rapidly at 37° C, coagulating milk and forming gas 

 in sugar media. In general, Hammerl failed to find 

 colon bacilli in the river by this method, except immedi- 

 ately below the various towns situated upon it; at these 



