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Diphtheria investigations.—Including 97 reswabs, a total of 4,237 swab cultures
(4,206 from throat and nose, and 31 from ears) were examined and found to yield
3,981 negative results and 256 in which bacilli morphologically resembling diphtheria
were reported; of the latter cultures 207 were submitted to animal test for virulence,
152 (73.4 per cent.) proving virulent and 55 non-virulent. Among the 4,140
primary swabs, 213, or 5.1 per cent. of those swabbed proved positive, including
3 positive out of 31 swabs from ears.
Ringworm and favus.—A total of 464 hair specimens yielded 125 in which
fungus was present, 87 being of the small spore and 37 of the large spore variety of
ringworm, but only one favus.
Sputum,.—Eighteen specimens from the same number of individuals were
examined for tubercle bacilli, with positive results in 5.
Gingivitis (oral infection).—A total of 89 slide preparations were examined from
the gums and buccal mucous membrane of 23 children in whom the organisms
associated with Vincent's stomatitis had been found in the primary smears.
Miscellaneous.—(1) Slide preparations from the cervix, vagina, or urethra of
35 individuals were examined for the presence of gonococci; 6 were regarded as
positive, 10 doubtful and 19 negative.
(2) Chemical and microscopical examinations were made of five specimens
of urine and of one specimen of cerebro-spinal fluid.
(3) Bacteriological examinations were made of a specimen of faeces with negative
results for the Salmonella group, and of samples of cellophane vaccination
dressings, and bamboo cane, without yielding evidence of specific pathogenic contamination.
(4) Throat and nose swabs from 9 individuals were examined for evidence of
scarlatinal infection ; all proved negative, except one, in which heemolytic streptococci
were found.
(5) In two cases of conjunctivitis, smears from the conjunctivae showed the
presence of cocci and bacilli, not identified as specific causative organisms.
Milk.—Sixteen samples of school milk were examined bacteriologically; 10
were reported as unsatisfactory and six as satisfactory.
Water examinations.—(1) Institutional supplies.—Examinations were made of
532 samples from 30 establishments.
(2) Swimming baths.—Four samples of the water from separate baths yielded,
on the whole, satisfactory results.
Preparation of media.—During the year approximately 80 litres of various media
for cultural use were prepared at the County Hall laboratory.
Work of the chemical branch
The work of the chemical branch is carried out at three laboratories, viz.,the
central laboratory at County Hall, and the laboratories at the northern and southern
outfall works.
The work done at the central laboratory consists mainly of the chemical examination
of materials of all kinds bought by the Council, for use in its numerous institutions
or for its other activities. The greater portion of these are materials supplied
under contract to the Council's specifications, where chemical analysis is essential
to ensure that the quality of the goods delivered is equal to that specified. In
addition, analysis is made of samples of air in tunnels, foods, etc., materials which
have failed in use, and other matters arising out of the Council's undertakings. A
considerable number of samples have been examined in connection with the
Petroleum Act, 1928, and the Fertilizers and Feeding Stuffs Act, 1926.
A systematic determination is made of the amounts of sulphur in air both in
London and in urban areas in connection with the scheme of the Department of
Scientific and Industrial Research for the investigation of atmospheric pollution.
An important part of the work of the branch consists of the consideration of,
and giving advice on, matters involving scientific questions in connection with the
various branches of the Council's work.