64 



IOWA ACADEMY OF SCIENCES. 



absorption may, however, be given some attention, as this 

 part of the analytical work has not reached a satisfactory 

 position. The method of oxygen absorption used is what 

 may be called the " English method " and was first pro- 

 posed by the Association of Public Analysts of England 

 and is outlined in connection with another investigation 

 published recently.* 



In the analyses of the deep well waters the amount of 

 free ammonia at once attracts attention. This is not a 

 new observation but has been recognized for some time as 

 quoted by Mason. f 



THE SANITARY ANALYSIS OF WATERS FROM SOME OF THE DEEP WELLS OF 



IOWA. 



(1) 



(2) 



980 feet of casing. 

 1, 300 feet of casing. 



"The 'free ammonia' in artesian wells is often excessive, 

 under circumstances that make animal contamination an 

 impossibility, and even rain water, freshly collected after 

 periods of long drought, will often exhibit properties calcu- 

 lated to mislead the analyst." 



•Weems & Brown. Influence of Chlorine as Chlorides in the Determination of Oxygen 

 Consumed in the Analysis of Water. Proc. Iowa Acad, of Sciences, 8. p. 87. 

 +Water Supply, p. 392. 



