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 388. “ “ “ 
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. 
