A simple method of water analysis : especially designed for the use of medical officers of health / by John C. Thresh.

Date:
1897
Catalogue details

Licence: Public Domain Mark

Credit: A simple method of water analysis : especially designed for the use of medical officers of health / by John C. Thresh. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

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    Examination of a Sample of Drinking-watkh FROM RaIN-WATKR TaNK No. 1. Odoher mh, 1896 Source ami possihility of contamination.—Collected on a clean surface. Not filtered. No possibility of contamination. A fair sample of Avater collected from a roof with a rain-Avater separator. Chemical and Physical Examination 1. Colour in 6-m. column.—Faint blackish-yellow tint. Turhidity.—Very slight. 2. Odour.—Faint, sui generis. 3. Residue left on ei-aporalion.—Very slight. Signs of charring when ignited. 4. Free ammonia.—Large trace. ■ 5. Chlorine.—About ^ a grain per gallon. Equivalent of common salt.—Under 1 grain per gallon. C). Nitrites.—None. 7. Nitrates.—None. ■ 8. Hardness.—About 2°. 9. Lead.—None. •10. Zinc, iron, and co])per.—None. '11. Oxygen ahsorbed in 15 min. at 212° F.—Over •15 grains per gallon. From the examination of the source of the water herein referred to, and the results obtained by analysis, I am of opinion that the water is admirably adnpted for domestic purposes if always as carefully collected. It must be remembered that such waters act energetically on lead, zinc, and iron. Earthen- ware or slate cisterns should be used for storage, and block-tin pipes for distribution of that portion used for drinking and culinary purposes.