An inquiry into the relative efficiency of water filters in the prevention of infective disease / by G. Sims Woodhead and G.E. Cartwright Wood.

  • Woodhead, German Sims, Sir, 1855-1921.
Date:
1898
Catalogue details

Licence: Public Domain Mark

Credit: An inquiry into the relative efficiency of water filters in the prevention of infective disease / by G. Sims Woodhead and G.E. Cartwright Wood. Source: Wellcome Collection.

Provider: This material has been provided by The University of Leeds Library. The original may be consulted at The University of Leeds Library.

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    in it frequently escape the antiseptic action of the gastric juice, by being passed on at once from the stomach into the intestines. The presence of these large numbers of water organisms in the water from such a filter is not, in our opinion, a matter of indifference, since these undoubtedly must set up fermentative changes, and thus tend to digestive disturbance. Inefficient table and domestic filters are not therefore merely incapable of obviating danger, but when used even with a good water, in all probability tend to render it unwholesome. The evil resulting from the misleading statements of the filter vendors is most obvious when such filters are used for the purpose of purifying waters which are regarded as dangerous. Owing to the misplaced confidence reposed in these statements, the common-sense precaution of boiling water is omitted, and in this way they have worked unmiti- gated evil. When we read that one manufacturer alone has supplied no fewer than 17,000 of these inefficient pocket filters to our army, which were probably used for filtering waters open to contamination, the magnitude of the danger may, to some extent, be realised, especially as disease organisms once having gained access to the filter would be carried about from place to place. As the outcome of this investigation, we believe that we are warranted in concluding that we have been able to settle the principle on which must be based the method of testing the efficiency of filters in preventing the transmission of water- borne infective disease. The method had already been suggested by Gruber and his pupils, but we have been able to carry out experiments on so many types of filters, and over such prolonged periods, that we may now hopt; that this vexed question has been finally set at rest. We wish to take advantage of this opportunity to express our great indebtedness to the Laboratories Committee of the Royal Colleges of Physicians (London) and Surgeons (England) for placing so unreservedly at our disposal the facilities for carrying on so prolonged and extensive a series of -experiments. We must also thank Mr. James Millar for the'valuable assistance he has given in helping to carry out and to record the results of such a long and laborious investigation. G. E. C. W. London, 22nd February, 1898.