IOWA ACADEMY OF SCIENCES. 85 



THE INFLUENCE OF CHLORINE AS CHLORIDES 

 IN THE DETERMINATION OF OXYGEN CON- 

 SUMED IN THE ANALYSIS OF WATER. 



J. B. WEEMS. J. C. BROWN. 



One of the most valuable determinations in the analysis 

 of water and sewage is the determination of the oxygen 

 .consumed. In the deep well waters of the state, the 

 amount of chlorine in the form of chlorides in many 

 cases is very high, as may be seen by the investigations of 

 the Geological Survey,* on the artesian waters. 



In this investigation it was found that chlorides were 

 present in the following amounts, as shown in the analysis 

 of water from the places named: 



McGregor 967. parts per million. 



Manchester 80. 



Boone 152. " 



Davenport 273. " " '' 



Centerville 3S8. 



The selections made contain large amounts of chlorine 

 as chlorides, and while there are many other waters which 

 contain only small quantities of chlorides, it is readily seen 

 that the deep well waters vary between wide limits in the 

 amounts of this substance present in them. It may be said 

 in a general sense, that the amount of chlorine found in 

 the analysis of the deep well waters of the state varies from 

 a small quantity to 1000 parts of chlorine as chlorides per 

 million. 



It has been recognized for some years that the presence 

 of chlorine in combinations in the form of chlorides has 

 a certain effect upon potassium permanganate when 

 boiled in the presence of sulphuric acid; and the problem 

 which naturally presents itself is, to what extent is the 



* Iowa Geological Survey, Vol. 6. 



