SEWAGE POLLUTED WATER.

SEWAGE POLLUTED WATER.

In a paper by Major W. H. Horricks, of the Brit ish Royal Army Medical Corps, on the bacillus coli communis as an indication of sewage contamination of water supplies, the author points out that, although the bacillus coli communis has been regarded as one of the most important indications of sewage contamination of water, nevertheless, much confusion exists as to the cultural characteristics which are to he considered diagnostic of this particular organism. He then shows that the cultural reactions may vary to a wide extent, when the organisms are grown on ordinary nutrient media. He has made elaborate experiments, and as the results of his investigations he comes to the following conclusions: (1) The bacillus coli communis is the only organism of the coli type on which implicit reliance can be placed as an indication of sewage contamination, (2) The bacillus coli communis should not be present in 200 c. c. of water derived from properly protected deep wells and springs. (3) If the bacillus coli communis is not found in 10 c. c. of upland surface waters, it is practically certain that the supply has not been contaminated with human fecal material. These conclusions are further strengthened by Messrs. H. W. Clark and Stephen D. Gage, of Boston, who, at the meeting of the Public Health association, held last October in Washington, read a paper “O11 the value of tests for bacteria of specific tvpes as an index of pollution,” in the course of which they pointed out that tests for the bacillus coli at the experimental station at Lawrence bad agreed well with the results obtained by chemical analysis and by inspection of the sources of the samples. Surface waters having the greatest relative population on their watershed had shown bacteria of the colon type more frequently than others with less population. Ground waters, on the other hand, unless grossly polluted, never showed bacteria of the colon type. Samples of shellfish from sources polluted and unpolluted had almost invariably shown the presence of bacillus coli in the polluted samples, and their entire absence in the noil-polluted sample.

In a paper by Major W. H. Horricks, of the Brit ish Royal Army Medical Corps, on the bacillus coli communis as an indication of sewage contamination of water supplies, the author points out that, although the bacillus coli communis has been regarded as one of the most important indications of sewage contamination of water, nevertheless, much confusion exists as to the cultural characteristics which are to he considered diagnostic of this particular organism. He then shows that the cultural reactions may vary to a wide extent, when the organisms are grown on ordinary nutrient media. He has made elaborate experiments, and as the results of his investigations he comes to the following conclusions: (1) The bacillus coli communis is the only organism of the coli type on which implicit reliance can be placed as an indication of sewage contamination, (2) The bacillus coli communis should not be present in 200 c. c. of water derived from properly protected deep wells and springs. (3) If the bacillus coli communis is not found in 10 c. c. of upland surface waters, it is practically certain that the supply has not been contaminated with human fecal material. These conclusions are further strengthened by Messrs. H. W. Clark and Stephen D. Gage, of Boston, who, at the meeting of the Public Health association, held last October in Washington, read a paper “O11 the value of tests for bacteria of specific tvpes as an index of pollution,” in the course of which they pointed out that tests for the bacillus coli at the experimental station at Lawrence bad agreed well with the results obtained by chemical analysis and by inspection of the sources of the samples. Surface waters having the greatest relative population on their watershed had shown bacteria of the colon type more frequently than others with less population. Ground waters, on the other hand, unless grossly polluted, never showed bacteria of the colon type. Samples of shellfish from sources polluted and unpolluted had almost invariably shown the presence of bacillus coli in the polluted samples, and their entire absence in the noil-polluted sample.