The theory and practice of hygiene (Notter and Firth) / by J. Lane Notter ... and W. H. Horrocks.
- James Lane-Notter
- Date:
- 1900
Licence: In copyright
Credit: The theory and practice of hygiene (Notter and Firth) / by J. Lane Notter ... and W. H. Horrocks. Source: Wellcome Collection.
Provider: This material has been provided by London School of Hygiene & Tropical Medicine Library & Archives Service. The original may be consulted at London School of Hygiene & Tropical Medicine Library & Archives Service.
39/1146 page 17
![Comparative Value of the Various Sources of Water-Supply. This depends on many circumstances. Spring-water is both pure and impure in dilferent cases; and the mere fact of its being a spring is not, as sometimes imagined, a test of goodness. Frequently, indeed, river-water is purer than spring-water, especially from the deposit of calcium carbonate j organic matter is, liowever, generally in greater quantity, as so much more vegetable matter and animal excreta lind their way into it. The water of a river may have a very different constitution from that of the springs near its banks. A good example is given by the Ouse at York ; the water of this river is derived chiefly from the millstone grit, which feeds the Swale, the. Ure, and the Nid, tributaries of the Ouse; the water contains only 13 parts per 100,000 of salts of calcium, magnesium, sodium, and a little iron. The wells in the neighbourhood pass down into the soft red sandstone (Yoredale series) which lies below the millstone grit; the water contains as much as 92*8 parts, and even, in one case, 137 parts per 100,000 of total solids ; in addition to the usual salts there is much calcium chloride, and calcium, sodium, and mag- nesium nitrates. Shallow-well water is always to be viewed with suspicion; it is the natural point to which the drainage of a good deal of surrounding land tends, and heavy rains will often wash many substances into it. Instances are recorded where good and bad water was obtained from different levels in the same well. Classification of Drinking Waters,—The general characters of good water are easily enumerated. Perfect clearness; freedom from odour or taste; coolness; good aeration; and a certain degree of softness, so that cooking operations, and especially of vegetables, can be properly performed, are obvious properties. But when we attempt a more complete description, and assign the amounts of the dissolved matters which it is desirable should not be exceeded, we find considerable difference of opinion, and also a real want of evidence on which to base a satisfactory judgment. ThefoUoAving tables are given by the Rivers Pollution Commissioners:^ 1. In respect of wholesomeness, palatabihty, and general fitness for drink- ing and cooking:— (I. Spring-water, . . ) ^ ^ ^^ Wholesome •] 2. Deep-well water, . /^^y Palatable. \ 3. Upland surface water, 1 j . , , ^ ,, r 4. Stored rain-water, . ] moderately palatable. Suspicious Dangerous 5. Surface water from cultivated land, . . i 6. River-water, to which sewage gains access, . [ palatable 7. Shallow-well water, J 2. Classified according to softness with regard to washing, &c.:— 1. Rain-water. 2. Upland surface water. 3. Surface water from cultivated land. 4. Polluted river waters, 5. Spring-water. 6. Deep-well water. 7. Shallow-well water. 3. As regards the influence of geological formation in rendering the water .sparkling, colourless, palatable, and wholesome. The following water- bearing strata are the most efficient:— 1. Chalk. 2. Oolite. 3. Greeusand. 4. Hastings Sand. \ 5. New Rod and Conglomerate Sandstone.](https://iiif.wellcomecollection.org/image/b2135764x_0039.jp2/full/800%2C/0/default.jpg)
