68 Kansas Academy of Science. 



so we have concluded that when we get the pipes completely 

 cleared of river water the city supply ought to show prac- 

 tically no bacterial contamination. 



The analyses above quoted show the extreme importance of 

 having a full and complete knowledge of the source of the 

 water before passing any judgment on its quality. A decision 

 that would apply to a river water would not apply to a well 

 water, and a decision on the quality of a well water might not 

 apply at all to an artesian-well water. The iron waters in the 

 underflow of the valleys of the Middle West are a class by 

 themselves. 



The standards ordinarily applied to shallow-well waters do 

 not apply at all here. Doctor Kinnicutt (Science, Vol. XXIII, 

 p. 56) would exclude as suspicious a water that had more than 

 the following quantities of nitrogen in 1,000,000 parts: In 

 free ammonia, 0.05; albuminoid ammonia, 0.08; nitrates, 0.10. 



Comparing the waters mentioned above with such a stand- 

 ard would be utterly futile. Then, afterwards the process of 

 aeration entirely changes the character of the water, and it 

 must be compared with surface-waters, in which more albu- 

 minoid ammonia would be allowable. 



Facts of this kind only emphasize the necessity for more 

 satisfactory chemical methods for water analysis, and a care- 

 ful study of each water by itself, without too close reliance 

 on standards that are fixed even for that particular class of 

 waters. 



