Heise: Chloride of Lime 



31 



Table VII. — Interaction of chloride of lime solution with varying concen- 

 trations of urea. 



[Water, 100 cubic centimeters: urea, additions as noted. Five cubic centimeters of chloride 

 of lime solution digested eighteen hours in the dark at 28°C] 



SERIES A. ADD1T1ON-11.0 MILLIGRAMS AVAILABLE CHLORINE. 



Urea. 



Available chlorine. 



Solution 

 added. 



Weisht 

 added. 



Consumed. 



Left. 



cc. 

 



0.1 

 0.25 

 0.50 

 1.00 



g. 







0.003 



0.007 



0.015 



0.030 



mg. 



0.05 

 10.3 

 10.8 (6) 

 10.8 (4) 

 10.8 



mg. 

 10.9 (5) 

 0.7 



0.1 (4) 

 0.1 (6) 

 0.2 



.1 



SERIES B. ADDITION— 11.8 MILLIGRAMS AVAILABLE CHLORINE. 











0.1 



11.7 



0.5 



0.01 (5) 



11.5 (5) 



0. 1 (5) 



1.0 



0.03 



11.5 



0.3 



2.0 



0.06 



11.4 



0.4 



3.0 



0.09 



11.3 (5) 



0.4 (5) 



4.0 



0.12 



11.3 



0.5 



6.0 



0.18 



11.2 



0.6 



7.0 



0.21 



11.1 (5) 



0.6 (5) 



8.0 



0.24 



11.1 



0.7 



9.0 



0.27 



11.0 



0.8 



10.0 



0.30 



10.8 



1.0 



11.0 



0.33 



10.6 (5) 



1.1 (5) 



12.0 



0.36 



10.4 



1.4 



13.0 



0.39 



10.3 



1.5 



14.0 



0.42 



10.1 



1.7 



15.0 



0.45 



9.9 



1.9 



16.0 



0.48 



9.8 



2.0 



GENERAL DISCUSSION 



Since there is no direct parallelism between the oxygen-con- 

 suming capacity and the amount of chlorine a water or sewage 

 is capable of taking up, the determination of chlorine-consuming 

 capacity, in spite of its limitations, is an important test in the 

 laboratory control of hypochlorite disinfection. Hairi(8) di- 

 gested 100 cubic centimeter samples with chloride of lime solu- 

 tion in excess (13 milligrams available chlorine) and titrated 

 after an hour in weakly acid solution. If digestion is carried 

 out at constant temperature in the dark, this procedure will give 

 concordant, relative values for the chlorine absorption. 



Elmanowitsch and Zaleski(4) recommended the determination 



