48 THE POPULAR SCIENCE MONTHLY. 



says (in the paper previously quoted), " Grounds for distrust in deter- 

 mining the purity of water are grounds for its rejection, especially 

 when brought into comparison with water from a source of undoubted 

 purity." 



It has been objected that no water outside the laboratory is abso- 

 lutely "pure ;" that water ordinarily available for town-supply is only 

 relatively pure, and that too high a degree of purity must not be ex- 

 pected, lest the cost of the works be too great a public burden. This 

 is true, abstractly, yet who will have the temerity to draw the line and 

 say : " Our town can and must stand such and such a death-rate, but 

 no more ; let us risk it and take our water from this contaminated pond 

 close by, and let the death-rate be so and so, rather than spend so many 

 thousands more in bringing pure living water from the everlasting 

 hills miles away, and thus reduce our death-rate to the minimum ! " 



The question of cost should never for a moment weigh against the 

 question of purity of quality. Foul, though apparently pure, water 

 may be the cheaper in the beginning, but it will surely be the dearer 

 to the community in the end, when it is remembered that health and 

 life itself tremble in the balance. Cost and quantity should not be 

 underrated, certainly, neither should quality. It is the frequent neglect 

 of this latter element of calculation, in designing works for the water- 

 supply of towns, that results in the frightful epidemics usually and 

 impiously attributed to the " mysterious dispensations of Providence," 

 rather than to human ignorance, or cupidity, or negligence. Recently 

 an English clergyman acitually preached to his j^arishioners that a dev- 

 astating fever among them was a visitation from God upon them in 

 punishment for their sins, while at the same time a gentleman, writing 

 to the authorities to complain of the water-supply, dipped his pen in, 

 and wrote with water from the river instead of ink ! 



Setting aside now all other sources of water-contamination, let us 

 see what the best authorities say would be the effect on the quality of 

 drinking-water derived from agricultural lands enriched with organic 

 manures, and especially that manure which consists largely of human 

 excreta from privy-vaults and the contents of house cesspools. 



Two propositions may here be stated that are perfectly sustained 

 by proof : 



1. Any organic matter will poison water, and is not removable ex- 

 cept by boiling or distillation. 



2. Hmnan excremental matter is the most dangerous organic sub- 

 stance likely to be contained in privy-vaults or cesspools, and its viru- 

 lence is largely increased when it consists partly of the excrementitious 

 matter of cholera and fever patients. 



We will take as an example a compactly-built tov.'n of some fifteen 

 thousand inhabitants. Each habitation has its one or more privy- 



