MICROBES IN THE WATER SUPPLY OF LONDON.
LONDON’S water supply is regularly and efficiently inspected by Inspectors that not only do inspect but also know how to inspect. Hence that inspection is one of the main factors which insures for the British metropolis the healthy conditions enjoyed by its inhabitants. The inspection of the water supply of London is insisted upon by the health authorities, who, by the way, do not change with every change in the municipal administration, and are besides presided over by experts in their peculiar lines, each of whom is responsible to government for the due performance of his work. Among their duties is that of immediately communicating with any one of the companies which supply the metropolis with water, whenever the water they furnish contains more than a certain proportion of microbes, in order that they may be made aware of the fact that their filters are not doing their work properly and require attention. In this way the desired results are obtained. The bacteriological analysis of the water Is conducted in the most thorough manner—the results being tabulated and made public at regular intervals. According to the testimony of Sir William Crookes, F. R. S., the bacteriological examination of 470 samples of London water showed that six per cent. contuined more than 100 microbes the cubic centimetre. The percentage for the two or three months immediately preceding was only two per cent., and the comparative impurity of the samples collected in December was accounted for by the large increase of rainfall over that of the previous month. As to these microbes, however, a number of special daily examinations failed to show the presence of any pathogenic bacteria in any of the samples of filtered water so examined, so that, whether or not there is danger to health from the presence of so many, or any non-pathogenic microbes (as to which a considerable difference of opinion exists), there can be no doubt as to the safety inuring to the consumer from the absence of the hurtful organisms. It would be interesting to institute a comparison between the filtered water as supplied to Londoners and the non-filtered Croton water of today. Time was when the latter had no rival for wholesomeness and purity. The experience of the last fall has shown a terrible falling off in that respect as in others. As for Philadelphia—no comparison is possible!