88 lOAVA ACADEMY OF SCIENCES. 



In the Kubel and Association methods, however, a reac- 

 tion would be expected and the permanganate acted upon 

 to a certain extent. As the results from the investigation 

 of these two methods were the same the following table 

 will give the amount of permanganate decomposed for 

 both methods in terms of oxygen consumed. 



Parts per million of ohlnrine as Oxygon consum- d in parts 



sodium chloride iu sample. per milliou. 



5 ('3 



10 08 



15 10 



20 13 



25 15 



50 18 



100 ■ 23 



200 28 



300 33 



400 3S 



500 48 



600 63 



700 72 



800 80 



mo 83 



1000 V)8 



1100 1.08 



1200 1.24 



1400 1.44 



1600 1.56 



1800 1.68 



From these results it is seen that in waters that contain 

 large quantities of chlorides, it is well to give consideration 

 to the action due to the presence of chlorides on the per- 

 manganate solution where the Kubel or the Association 

 method is used, for the determination of oxygen consumed. 



