Chemical Analysis of Potable Waters. 



In all this nothing has been said about disease germs, for like the 

 chemist's atoms their existence even is not proved, though it seems cer- 

 tain that many diseases are produced by specific poisons, of the nature 

 of which we as yet know little,"and that in certain diseases these 

 poisons are contained in the excreta, which may give rise to these 

 same diseases through the use of drinking water to which they have 

 gained access. All filth is not necessarily harmful, a statement which 

 hardly needs proof, but the truth of which is well seen in the case re- 

 ported by Dr. J. C. McKee, TJ. S. A., in the New York Medical Journal 

 for November 3, 1883, in which water containing large quantities of pu- 

 trescent animal matter was used for two weeks by a garrison of eighty 

 people, including men, women and children, without producing any 

 deleterious effects, but if some specific kinds of filth are poisonous, 

 then the use of a given water which is liable at any time to become 

 specifically polluted, should be abandoned, if possible, in favor of a 

 safer source of supply. 



And lastly as regards the natural purification of polluted waters, 

 while the tendency of all organic matter, animal or vegetable, is to- 

 ward ultimate death and final destruction by oxidation, it is as yet 

 impossible to say how rapidly such a destruction goes on in many 

 cases. The Eivers PollutionCommission mixed urine with water, in 

 the proportion of one part of urine to 3,077 of water, agitated the 

 mixture from time to time and analysed samples. At the end of the 

 eleventh day the improvement in the water was so inconsiderable that 

 other experiments were made in which a stream of impure water was. 

 allowed to flow from one vessel to another, and was thus freely exposed 

 to the air, and as a result of these experiments the commissioners con- 

 cluded that purification by natural oxidation had been greatly over- 

 rated, and that " there is no river in the united kingdom long enough 

 to secure the oxidation and destruction of any sewage which may be 

 discharged into it even at its source." They also conclude that 

 "rivers which have received sewage, even if that sewage has been pu- 

 rified before its discharge are not safe sources of potable water." (Riv- 

 ers Pollution Commissioners' 6th Report, pp. 134-8.) Upon this 

 point Frankland says : " Twelve years ago there was a general im- 

 pression amongst chemists and others that polluted water quickly re- 

 gained its original purity by spontaneous oxidation. The opinion had 

 no foundation in quantitative observations ; indeed there was not a 

 single experimented fact to prove it. * * * The impression had 

 gained currency from the improved appearance of a polluted river 

 after a flow of a few miles. * * * Two classes of persons strongly 

 interested in its acceptance were chiefly instrumental in the origina- 

 tion and diffusion of this opinion. These were, first, the polluters of 

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