The examination of waters and water supplies / by John C. Thresh.

  • Thresh, John C. (John Clough), 1850-1932.
Date:
1904
Catalogue details

Licence: Public Domain Mark

Credit: The examination of waters and water supplies / by John C. Thresh. Source: Wellcome Collection.

    79/500 (page 59)
    The following table, compiled from the returns for March 1903, show that there is some general correlation between the colour and the amount of organic matter in the various London supplies. The figures are the averages for the month :— Water Company Colour Brown Bine Oxygen required by organic matter New River . . 11-5 20 •035 East London . 19-8 20 •059 Chelsea . 18*6 20 •052 West Middlesex . . 19-4 20 •056 Lambeth . 25*5 20 •072 Grand Junction . . 23-2 20 •070 Southwark and Vauxhall . 21-7 20 •058 The next table, giving Hie results of the daily examination of two of the supplies, shows, however, that there are many exceptions to the rule that the depth of the brown tint varies with the amount of the organic impurity. Date of Collection New River Co. East London Co. Colour Proportion of Brown to 20 Blue Oxygen required by organic matter Colour Proportion of Brown to 20 Blue Oxygen required by organic matter March 2 5 0-015 20 0-045 March 3 5 0-018 17 0-045 March 4 4 0-018 17 0-045 March 5 5 0-018 17 0-045 March 6 6 0015 18 0-037 March 7 6 0-022 17 0-041 March 9 16 0-037 18 0-045 March 10 14 0-049 20 0-049 March 11 18 0-049 21 0-046 March 12 20 0061 23 0-057 March 13 26 0-056 26 0-060 March 14 28 0-049 30 0-064 March 16 20 0054 27 0-070 March 17 16 0-054 21 0-072 March 18 15 0-041 20 0-067 March 19 13 0-037 20 0-067 March 20 12 0-043 20 0-074 March 21 13 0039 20 0-070 March 23 11 0-030 20 0-075 March 24 10 0-030 18 0-071 March 25 8 0-030 18 0073 March 26 6 0-030 16 0-069 March 27 6 0-022 18 0-060 March 28 6 0-026 17 0-060 March 30 6 0-026 19 0064 1 March 31 5 0-033 16 0-064 The oxygen absorbed is expressed in grains per gallon.