River water (no. 2) : a reply to Dr. Frankland / by Charles Meymott Tidy.

  • Charles Meymott Tidy
Date:
1881
Catalogue details

Licence: Public Domain Mark

Credit: River water (no. 2) : a reply to Dr. Frankland / by Charles Meymott Tidy. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    expresses himself, at the result, seeing that I expected that the materials in the sewage of easy oxidation would yield first and rapidly, leaving in the water those portions of the organic impurities most difficult to be disposed of. In discussing the peculiarities of Severn water Dr. Frankland criticises my statements about chlorine. I remarked that starting with a freshly polluted sewage river the chlorine would be large, but that the quantity would gradually decrease until it reached an amount equal to about one grain per gallon, the quantity commonly found in a good river water. I said probably the excess of chlorine was taken up by vegetation. Dr. Frankland disputes this. Dr. Mills remarks that “the weeds in a river’s bed into which sewage is poured constitute a natural sewage farm, capable of absorbing chlorides, phosphates and organic matter in the ordinary way. A great deal of the purification of the Thames must be owing to this cause. I should regard with grave apprehension any proposal to dredge the bed of the Thames above London.” I should wish to add that by supplying some growing watercresses for twenty-four hours with a water to which 1 had added forty grains of common salt per gallon, I succeeded in increasing the quantity of chlorides present in the watercresses by 220 per cent. With respect to Dr. Frankland’s criticisms on my experiments with sewage water in troughs I have only one word to say (for as far as I can see they remain absolutely unanswered) and that is that the sewage used was filtered. I should wish to express my regret that in quoting Dr. Frankland’s report respecting the River Wear at Durham as “of good quality,” I omitted, unintentionally, the succeeding words which I certainly ought to have quoted, “ considering its source.” I would suggest, however, that, without considering its source. Dr. Frankland’s analysis of the water (0166 of organic carbon, no previous sewage contamination being found in the turbid unfiltered water, and 0-082 of organic carbon in the filtered water) would not, even by Dr. Frankland, be regarded otherwise than as satisfactory. I now approach that part of my subject where, in addition to Dr. Frankland, I have to meet the criticisms of Professor Huxley and of Professor Tyndall. Let me therefore endeavour to state my precise line of argument, and then attempt to answer their objections. The Thames admittedly receives sewage in certain parts of its course. At Hampton the Water Companies take their supply from the river, and the filtered water is drank by nearly the whole of London. This, says Dr. Frankland, in efEect, is the cause of all your troubles and much of your disease. The supply of chalk water to London
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