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74
Copies of these 70 complaints were sent to the Borough
Engineer.
During the year Webb's Patent Sewer Gas Destructor Lamps
were fixed in the following situations:—
Netherwood Street, by Kelson Street.
Hemstal Road, by Lowfield Road.
Sumatra Road, near Kingdon Road.
Fairhazel Gardens, by Goldhurst Terrace.
Broomsleigh Street, opposite the School.
The importance of the problem of sewer ventilation was
emphasized during the year 1908 by the publication, in the Annual
Report of the Medical Officer of the Local Government Board,
of an important report by Dr. F. W. Andrewes on "Micro-organisms
present in sewer air and in the air of drains." Dr. Andrewes, it
will be remembered, was engaged by the Borough Council
in 1905 to investigate the air of the Hampstead sewers
in order to determine whether the emanations from the
ventilating grids, which were the subject of many complaints,
were likely to cause disease. Prior to Dr.
Andrewes' observation in Hampstead there was a fairly general
concensus of opinion amongst bacteriologists that under ordinary
conditions sewage does not give up its own specific bacteria to the
air with which it is in contact. The earlier experiments had shown
that sewer air contained fewer bacteria than fresh air, and such
bacteria as were found in sewer air were shown to be of the same
species as those found in fresh air. But since these experiments,
which were made for the most part about fifteen years ago, great
improvements have been effected in bacteriological technique, and
Dr. Andrewes, in making his Hampstead observations, was able to
employ methods of investigation that were much more refined and
trustworthy than those upon which the earlier workers had to
rely. His results threw grave doubt on the view then commonly
held that "the bacteria of sewer air are derived only from the
fresh air and not at all from the sewage." He obtained evidence
that "sewer air may be the bearer of micro-organisms derived from
sewage itself," and his observations led him to the following conclusions:—