A treatise on hygiene and public health, with special reference to the tropics / by Birendra Nath Ghosh and Jahar Lal Das.

  • Ghosh, Birendra Nath, 1882-1957.
Date:
1912
Catalogue details

Licence: In copyright

Credit: A treatise on hygiene and public health, with special reference to the tropics / by Birendra Nath Ghosh and Jahar Lal Das. 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.

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    Each bottle should be distinctly labelled to correspond with the official letter or invoice. For bacteriological examination either a sterile stoppered \ bottle or a hermetically sealed flask should be used. In case of a flask break the sealed end in the water when the water J will make its way in. Take it out and seal it again. In every case of bacteriological investigation the examination should be made as early as possible after the collection of sample. About two to four ounces of water is usually necessary for such an examination. I A Physical Examination'of Water—This by itself cannot form a basis of opinion, but brilliant, clear, non-smell-j ing, and highly gerated water is alone fit for human consump- tion. Note the following:— (a) Colour —Pour the water into a colourless glass tube about two feet deep placed on a white plate and note the colour. Tlie lon-er the tube the better is the colour noticed. Pure water hns a bluish or greenish tinge. Yellow or brown colour generally indicates contamination with animal organic matter mainly sewage?butmayalsobedueto vegetable matters or salts of Clearness.—Shake a small quantity of water and iron. note whether it looks hazy:or not. Heavy sediments rapidlj fall to the bottom. . J (A Lustre or brilliancy.—Some water is distinctly dull or of slimy appearance. Clear and sparkling water contam (J\j9 clilU Uli.. q (d) Taste.—Water that tastes bad should be rejected. (e) Smell.-Smell of hydrogen sulphide when heated to boiling indicates contamination. B Chemical Examination of Water: tn\ -Reaction —This is taken with a litmus paper or by • ( ) Son of Phenolphthalein which when added ft]