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.
49/1146 page 27
![may, however, be sometimes slightly coloured with vegetable matter. Cultivated lands, with rich manured soils, give a water containing both organic matter and salts in large quantity. Some soils contain potassium, sodium, and magnesium nitrates, and yield these salts in large quantity to water. In towns and among the habitations of men, the surface water and the shallow-well Avater often contain large quantities of calcium and sodium nitrites, nitrates, sulphates, phosphates, and chlorides. The nitrates in this case probably arise from ammonia, ammonium nitrate being first formed, Avhicli dissolves large quantities of lime. Organic matter generally exists in large amount, and sloAvly oxidises, forming ammonia and nitric acid. In some cases butyric acid, which unites with lime, is also formed. Marsh water always contains a large amount of vegetable organic matter ; it is not unusual to find of volatile solids from 17 to 57 parts per 100,000, and in some cases even more. Suspended organic matter is also common. The salts are variable. A little calcium and sodium in combination with carbonic and sulphuric acids and chlorine are the most usual. Of course, if the marsh is a salt one, the mineral constituents of sea-water are present in varying proportions. Water taken from wells sunk in the vicinity of cemeteries contains ammonium and calcium nitrites and nitrates, and sometimes fatty acids, and much organic matter. Lefort found a well of Avater at St Didier, more than 330 feet from a cemetery, to be largely contaminated Avith ammoniacal salts and an organic matter Avhich Avas left on evaporation. The Avater Avas clear at first, but had a vapid taste, and speedily became putrid. The Avater from old givaveyards (disused) may shoAv less organic matter, but it Avill contain large quantities of .nitrates, chlorides, &c. The Avater derived from deep Artesian Avells is usually of excellent quality and contains only a very minute quantity of organic matter. In some cases, hoAvever, the Avater is so highly charged Avith salin^ matter as to be un- drinkable; the Avater of the Artesian Avell at Grenelle contains sufficient sodium and potassiimi carbonates to make it alkaline; there is also present in it a considerable amount of free ammonia. When not very hard, these Avaters are of good quality, clear and colourless, and, OAving to the depth of the Avell, are usually of a uniform temperature throughout the year. The Avater is not Avell aerated, and therefore not so palatable as spring Avater, Some Artesian Avell Avaters are Avarm; these are generally used for medicinal l)Urposes. Others, again, contain iron or are aperient; these are unfitted for ordinary drinking purposes. The Artesian avcUs in London are alkaline from tlie presence of bicarbonate of sodium, and hence are very soft. Water from Avells near the sea frequently contains so much saline matter as to taste quite brackish, although the organic matter may not be very large. In some samples from Shoeburyness (analysed at Netley) the total solids ranged from 148 to 312 parts per 100,000, the cldorides being from 31 to 93 : mean of six sam])les—236 total solids and 50 of chlorides. In one sam])le, hoAvever, the albuminoid ammonia Avas only 0-007 per 100,000, and in five tlie oxygen required for organic matter Avas under 0'075 ])er 100,000. Samples from Avells at Gibraltar yield in some cases large quantities of solids; in one instance as much as 338 parts of total solids and 244 of chlorides in 100,000. At Landguard Fort, Avater from a boring 150 feet deep yielded more tlian 700 parts of solids and 540 parts of chlorides. Kain-Avater may be contaminated by Avasliiiig tlie air it falls tbrougli, but more by matters on the surface on Avhich it falls, such as deciiying leaves, bird droppings, soot, or otlicr matters on tlio roofs of houses; it also](https://iiif.wellcomecollection.org/image/b2135764x_0049.jp2/full/800%2C/0/default.jpg)
