The organic analysis of potable waters / by J. A. Blair.

  • Blair, J. A. (James Andrew)
Date:
1891
Catalogue details

Licence: Public Domain Mark

Credit: The organic analysis of potable waters / by J. A. Blair. Source: Wellcome Collection.

    44/136 (page 32)
    complete oxidation. During three hours, at ordinary temperatures, starch and cane sugar absorb almost no oxygen compared with the quantity required for the complete oxidation of these substances. The proof of these statements will be shown later on, in a series of tables. After the consideration of this objection to the oxygen process as usually carried out, the question naturally arises—Can this objection to the oxygen process be overcome or minimised ? Hitherto, the best method of carryingout the oxygen process is the one recommended by Professor Tidy, the working details of which were published in the ‘ Chemical Society’s Journal’ for 1879. Since then his plan has been usually followed, some analysts modi- fying the time of exposure of the water to the action of the oxidising agents, and others modifying the temperature. It has been suggested to keep the water in stoppered bottles at a temperature of 80° F. for four hours, whilst it is exposed to the action of the permanganate. If the quantity of oxygen absorbed by a water in a given time can be used as a reliable basis for classifying the organic purity of waters, even when this quantity of oxygen is only a small fraction of the total quantity the organic matter is capable of absorbing, it is reasonable to suppose that the nearer the quantity absorbed can be made to approach the quantity required the more satisfactory will be the