Symud i'r prif gynnwys
Cuddio Rhestr Erthyglau

4 erthygl ar y dudalen hon




SANITATION FOR THE PEOPLE. [BY DR. WALKER.] III.—METHOD (Continued). As one of the elements of nature, water is essential to life. The importance of its influence in nature is imperfectly recognized. Two thirds of the human body is composed of water, and in some things we are wont to call solid, the proportion is greater still- With so ubiquitous a substance, its power for good or evil is, as one would expect, enormous. It is usually wielded in nature as a beneficent influence, clean sing the atmosphere and the soil, removing im- purity and fertilizing the earth. In the animal body it is no less .an agent of blessing, carrying away effete and poisonous matters, and distributing nourishment to the tissues. But it may be the means of potent mischief by its very life-sustaining properties. Some forms of bacteria propa- gate in water, and make use of it as a channel by which disease is spread. The frightful scourge of Cholera is chiefly propagated by water, and recent case43, at Maidstone and Worthing prove that typhoid fever is also a water-bourne disease. The purity of the water supply in view of such dangers, and other which could be cited, is therefore of prime importance from a sanitary point of view. The source of the supply is the most important consideration, for there is no more foolish or wasteful policy than drawing water from an impure source, and then expending vast sums in removing the impurity. Yet that is the, egregious folly committed by the citizens of the first city in the world, originally from ignorance but latterly from cupidity and stupidity. The Corporation of Aberyst- wyth have been wise and farseeing in going to the lonely slopes of Plynlimmon for their water. No source is better than a breezy upland, practically uninhabited, and with a large area for collection. It is practically rain water unpolluted by smoke or bacteria. It is probably deficient in mineral salts, and by its softness liable to act on lead pipes and cisterns. A constant service, as at Aberystwyth, makes the latter unnecessary, and diminishes the danger from pipes by keeping them always full and excluding the air. Few towns are so fortunately situated as to secure such a supply. Rivers are most frequently drawn upon. If they are fed from springs and now through sparsely populated country if they are turbulent and rapid so as to be well aerated if they are not polluted by sewage or farm drainage or effluents from manufactures, they are wholesome enough. But how few rivers in this country fulfil these conditions. It is a disgrace to our commonsense and enterprise that so many of our beautiful rivers are poisonous to man and beast. Sewage and other poisonous matter never can be entirely got rid of by natural means, and the mud at the bottom remains more or less offensive. Lakes are sometimes used as the source of supply. When unpolluted by sewage or farm refuse and fed by a good supply of spring or mountain water, they are good enough, though care should be taken to draw from the surface only, and avoid the deeper and less pure layers. If they receive sewage or are fed,, from polluted streams or surface water from farm land they are utterly unsuited for drinking purposes. Carnarvon water supply is from such a source according to Sir W. H. Preece. Shallow wells, which at best contain sub-soil water, and are liable to contamination from the surface, or by infiltration, are a dangerous source of supply. Deep wells, especially tkose fed from springs, are fair but uncertain sources. Artesian wells, which tap sub- terranean reservoirs, produce a pure water, but one usually over rich in mineral salts. Boiling and chemical means may be used to soften such water, which, of course, comes also from chalky and lime stone soils, but it never is suitable for some people, and always a nuisance in domestic operations. A constant service is infinitely best, but where cisterns are needed, they should be of galvanized iron in a safe position from contamination, be kept covered, and ventilated, and frequently cleaned. The service pipes should be of glazed iron or composition, and the mains be kept at a distance from sewers and gas mains. When water is obtained from a source open to suspicion it should be filtered. It is obvious that filter beds should be as far as possible from reach of pollution, and not as in one London district separated by a hoarding from an extensive ash-shoot. The usual filter is sand and gravel in layers, but carbon and iron filters are used at great cost in some cases. Bacterial filtration is in the experimental stage, but promises to surpass all others. For domestic use carbon, iron or unglazed porcelain are best, but to be efficient require constant cleaning and frequent renewal. Where epidemic disease is prevalent or the water is known to be impure, filtration is but a broken reed to trust to. Boiling is the proper resource, even if it makes the water insipid as a beverage. The appearance, taste, or smell of water is a poor test, as sewage contamina- tion often renders it bright and sparkling, and pleasant to taste, as in the historical St. George's Well in London, whose pellucid but polluted water was sent for from long distances, and was the means of spreading cholera broadcast in 1844. There is a fallacy, and a very ridiculous one, that alcohol renders impure water safe for consumption. You will be warned as I was not to drink the Seine water on visiting Paris without qualifying it. I paid no attention to the warning as I deemed it one of the many contradictory reasons urged for indulgence in alcoholic liquors, and I observed the Parisian drinking it freely with their liqueurs and eau sucre. Water examination is of the utmost importance as a sanitary precaution. It ought not to be a per- functory performance as it frequently is, but exhaustive and periodic. The examination I should be both chemical and bacteriological, and the presence of impurity reported without fear or favour. The quantity of water needed is found on an average to be from 25 to 30 gallons per, head of popula- tion. At the seaside, sea water should be use for road watering both from economical and sanitary reasons. -f.