Water supply : considered mainly from a chemical and sanitary standpoint / by Wm. Ripley Nichols.

  • Nichols, Wm. Ripley (William Ripley), 1847-1886.
Date:
1883
Catalogue details

Licence: Public Domain Mark

Credit: Water supply : considered mainly from a chemical and sanitary standpoint / by Wm. Ripley Nichols. Source: Wellcome Collection.

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    is in the habit of drinking a soft water generally experiences some derangement of the digestive organs on beginning to use hard water, and vice versa. It is contended by some that the human system needs salts of lime, etc., that these compounds are furnished in an assimilable form in water, and that, consequently, a somewhat hard water is more advantageous for town supply ; statistics have been brought together to support this view by comparing the death rate of various towns with the hardness of the water supply, but the death rate depends upon too many factors to be used as the chief argument in this connection. It is however, the result of general observation that a hard water of which the hardness is due to salts of magnesia or to sulphate of lime is not well suited for drinking, and is injurious to most PerWaSters, especially surface waters, containing much vegetable matter are also, in some cases, unwholesome The water of marshes is sometimes the cause of diarrhoea and other diseases of this character, and is supposed by some to cause malaria and other fevers (see also page loo). The mere presence of vegetable organic matter, however, is not sufficient to produce these effects because many waters which are quite deeply colored by vegetable matter are proved by experience to be perfectly wholesome While some waters are thus, in their natural condition unwholesome and may be the cause of sickness, the attention of sanitarians and water experts is directed nowadays principally 0 tt effect of water which is polluted by the waste materials from manufactories and dwellings, or by the sewage o! towns and cities- audit is generally held, especially in England and the Uni d Sutes, that water thus polluted may be, and frequently 1 the cause of certain specific diseases. Before ^cussing this question directly, it is important to have a genera idea of the present prevailing view with reference to the so-called zymotic dSases,and to understand what is meant by the « genri theory Many clear liquids containing organic matter of animal or vedbfe origin-such, for instance, as infusions of hay infusion o turnip, urfne, etc., etc,-* exposed to the air gradu^ be- come turbid or cloudy, or, perhaps, a film forms on the surface of The liquid, or a deposit^he^^^ * See, however, a remark by Professor Mallet, page 26.