View report page

43
expenditure is incurred, no long term effect can be obtained. At the end of the year an
experiment was in progress, using ultra-violet radiation. Chlorophyll products which
also contained some formaldehyde and pine oil were examined but these are of limited
efficacy.
Chemicals, drugs and medical supplies
This group comprises a wide range of materials. Various proprietary vitamin preparations
were examined and in one case the accessory food factors were negligible in
concentration and in another very expensive when compared with the British
Pharmacopaeia preparations. Some complaints (e.g., oculent albucin and halibut liver
oil) were investigated and found either to be groundless or due to personal idiosyncrasy.
Complaint of the cloudiness of mist, ferri: sulph. pro infantibus was due to the orange
flavouring added and in no way deleterious. Warning was given on some proprietary
silver cleaning compounds which contained thiourea and could, by regular ingestion
cause depression of the thyroid gland. A powder supposed to give a chromium finish
was found to be potassium sulphostannate, magnesium powder and an organic acid.
The metal deposited was tin and not chromium and had a soft and not very durable
finish. Various zinc oxide plasters were evaluated, especially as regards their action on
the skin, and a compound found in a building was shown to be calcium hydride, a
dangerous chemical if wetted with water, for inflammable and explosive gas (hydrogen)
would be evolved.
Insecticides and fungicides
The Council's specifications for insecticides which include both D.D.T. and
Gammexanc formulations continue to give satisfaction and economical treatment.
Many proprietary products marketed at a greater price based on these chemicals were
examined and, as a result, no modification in the present specified products was advised.
Attention was called to the spraying of absorbent surfaces with insecticides with a
kerosene base for, although the base may have satisfactory evaporation characteristics,
an odour may linger for a considerable time and, furthermore, the efficacy of the
spraying treatment is adversely affected if the absorption is high.
A proprietary product, claimed to produce a film permanently lethal to insects, was
examined but the film was found to be highly inflammable and so would increase the
fire risk of the premises. It was, of course, rejected because the risk of fire must be
carefully considered and it is futile to reduce one nuisance and cause danger in another
important direction.
The so-called seaweed flies reported on the South Coast were found at the Southern
Outfall Works in November. They were attracted to the laboratory when chloroform
was used. They did not bite, but their presence was, to some degree, a nuisance.
Gammexane proved most effective for their destruction and 110 difficulty was experienced
in dealing with the trouble.
Detergents
Kitchen and
general
cleansing
Under this heading are included the examination of many soaps of all types supplied
under contract to L.C.C. specification and also the special powder incorporating
synthetic detergents for washing up in the Council's establishments. These specifications
are constantly under review with the object of obtaining maximum efficiency at the
minimum cost. New tests were introduced for the assessment of efficiency of washing
up and work was initiated to determine the general bacteriological condition of crockery
when a variety of different detergents, with and without germicides, were employed.
Detergent tablets have been introduced in eight kitchens and, after an extended
trial, the policy of using the material in this form will be decided.