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31
Chemical branch
The work of the chemical branch was carried on during the year at the three
laboratories, the total number of samples examined being 14,917, and Mr. C. J. Regan,
the Chemist-in-Chief, has submitted the following report:—
"A large proportion of the work was of a consultative or advisory nature
and on the practical side much of it was of an investigational character. The
great advances made during the past few years in the application of science,
not only to the use of war but also in industry and medicine, have emphasised
the help which it (and as far as this Branch is concerned particularly chemistry,
physics, etc.) can give in solving numerous problems which arise in connection
with the Council's service. The liaison made with many research associations
and similar bodies has been a considerable aid in this respect. It is impossible
to quote more than a few instances of the types of advisory work done during the
year, but that of formulating or commenting on specifications for the supply of
many materials or for the performance of operations of various kinds should be
mentioned (e.g., supply of various foods, comments on painting specifications):
also the frequent conferences with officers of the Chief Engineer's Department
in connection with sewage disposal problems. Among other special cases
involving advice or investigation were :—
Central
laboratory
"(1) Rapid advances have been made in the field of insecticides during
the war years and the materials developed were carefully studied throughout.
Both D.D.T. and Gammexane were found to be great improvements on the
types previously available and each has its special virtues. The use of
these was developed in the service to replace the less efficient materials
employed in the past.
"(2) In co-operation with the Meals Service, work on the analysis and
assay of meals in regard to various aspects of their nutritional value was
continued. Special surveys were conducted as to the vitamin C content
and a report was prepared including general considerations as to the
quantity of the vitamin required, the ease of its destruction by incorrect
methods of storage, cooking and subsequent treatment, seasonal variations,
etc.
"(3) The Architect requested that a report should be made on the
general question of the utility of waterproofers in concrete. Both the
'integral' and the 'surface' type were considered and it was concluded
that these were of use in certain cases. Particularly as regards the 'surface'
type, it was recommended that the 'coloured' class was most likely to give
satisfactory results as the 'colourless' type was still in an experimental
stage.
"(4) The submission for analysis of a proprietary substance sold for
use as a mineral salts addition to cattle foods caused consideration to be
given to the general question of the necessity or otherwise for such mineral
supplements. Admittedly in the event of the diagnosis of a deficiency
disease it can be valuable, but the opinion was expressed that, failing that
condition arising, there is no need for the general adoption of the use of
such supplements, providing that there are also no soil deficiencies at the
farms in question in respect of the minerals concerned.
"(5) Several failures in service of metals were investigated. (a) The
corrosion of calorifier tubes (copper) at a hospital was attributed mainly to
the inferior quality of the metal, the presence of zinc lowering the corrosion
resistance. The condensate was potentially corrosive in view of its dissolved
oxygen and carbon dioxide content. Remedies suggested were the use of a
more resistant metal and the installation of a deäerator. (b) The failure of