114 



The Philippine Journal of Science 



1916 



Many substances are known * to affect the chlorine consump- 

 tion, notably albumin and its decomposition products, urea, 

 glycocol, peptone, asparagin, and the like. We have determined 

 the chlorine-consuming power of a number of different sub- 

 stances, using the following method : 



Two hundred cubic centimeter samples of water, or else the 

 substances under examination dissolved in 200 cubic centimeters 

 of distilled water, were placed in glass-stoppered bottles. To 

 each sample a known excess of clear (filtered) calcium hypochlo- 

 rite solution was added. The bottle was stoppered and allowed 

 to stand at room temperature (30° C.) for two hours in the 

 diffused daylight of the laboratory. After digestion with hypo- 

 chlorite, 2 cubic centimeters of 10 per cent potassium iodide 

 solution and 2 cubic centimeters of 25 per cent phosphoric acid 

 were added to each sample, and the liberated iodine was titrated 

 with 0.02N sodium thiosulphate solution, starch being used as 

 an indicator. 



The differences in chlorine consumption are shown in Table IX. 



Table IX. — Chlorine-consuming power of different substances. 



Substance. 



Chlorine 

 added. 



Chlorine 



con- 

 sumed. 



Chlorine 

 con- 

 sumed 

 per liter. 



Remarks, 



Distilled water ._ 



mg. 

 6.6 

 6.6 

 6.5 

 1.0 

 6.6 



6.5 

 6.6 

 6.6 

 6.5 

 3.4 



mo. 

 0.16 

 0.2-0.5 

 0.2-0.6 

 0.24 

 0.75 



0.28 



0.7 



4.4 



6.6 



2.0 



mg. 

 0.76 

 1.0-2.6 

 1.0-3.0 

 1.2 

 3.75 



1.4 



3.6 



22.0 



28.0 



10.0 



Varies from day to day. 



Do. 

 Bureau of Science well. 

 From aquarium. 



Reservoir water (unchlorinated) 



Tap water (chlorinated) 



Artesian well water _._ 



Sea water 



200 cubic centi meters distilled water: 



Plus 0.0025 gram oxalic acid 



Plus 0.005 gram oxalic acid 



Plus 1 cubic centimeter urine -— 

 Plus 0.5 cubic centimeter ± sweat 

 Plus 0.5 cubic centimeter saliva - 



It is significant that the substances given off from the human 

 body cause the consumption of relatively large amounts of 

 chlorine. This emphasizes the necessity of personal cleanliness 

 on the part of the users of swimming pools if the purification 

 of tank water by means of chlorine is to be successful. A 

 thorough bath with soap should be taken before the pool is 

 entered to remove all body products so far as possible, not 

 only to avoid introducing into the water substances noxious per 



"Cf. Elmanowitsch and Zaleski, Zeitschr. f. Hyg. (1914), 78, 473; Hairi, 

 ibid. (1913), 75, 46. 



