SIGNIFICANCE OF COLON GROUP IN WATER 171 



is impossible, since many regions have no other water 

 available. 



On the other hand, it may be urged that it is better 

 to be on the safe side if possible. There is no doubt 

 that in the United States there is no difficulty in secur- 

 ing water supplies, either from the ground or by storage 

 or filtration, which only rarely contain colon bacilli 

 in I c.c. samples. It may, perhaps, be that in the thickly 

 settled and intensively cultivated parts of Germany 

 this is not the case. Where it is possible to obtain such 

 waters we believe it to be wise to do so. Ground 

 waters to which the colon baciUi from cultivated soil 

 penetrate and surface waters which still contain many 

 colon bacilK from fields and roadways may be generally 

 inocuous but there is always the chance that infectious 

 material may find its way to the soil and may enter, 

 along with the intrinsically harmless colon bacilli of 

 manure. The two most recent German contributions 

 to the subject are on the whole favorable to the colon 

 test if wisely and intelligently apphed. Fromme 

 (1910), from Dunbar's laboratory at Hamburg, concludes 

 from a survey of the literature and from his own studies 

 that " the finding of colon bacilli in water is a valuable 

 indicator of the quality of the water " and recommends 

 it particularly for ground-water spring waters and 

 filter effluents ; and Prof. Gartner, the head of the Hygiene 

 laboratory at Jena, after a thorough discussion of 

 previous work, comes to a much more conservative 

 conclusion than his pupil, Konrich (Gartner, 1910). 

 While emphasizing the shortcomings of the process 

 and deploring the tendency "to set B. coh on a high 



