M
M (1) 70
SPECIAL REPORTS.
Special reports were prepared during the year on "The Determination of Iron in Battery Acid," "Chinese Peanut Oil,” "Impurities in Chinese Tin," "Phosphorus Pentoxide Content of Chinese Rice," and "The preservation of bodies in Mortuaries."
RESEARCH.
An investigation has been begun into the degree of pollution of Hongkong harbour. To provide the necessary data for this work, a preliminary investigation was made into the nature and composition of Hongkong sewage. Eleven composite samples, each composed of 14 samples of sewage were analysed, and the average composition of the sewage thus determined.
The composition of the sea-water in the neighbourhood of the Colony in an unpolluted condition has also been determined, and data thus obtained for interpreting the results obtained on mixtures of sewage and sea-water in the harbour.
As regards the latter, some 373 samples of harbour water have been examined, some at High tide and some at Low tide. The work has not advanced sufficiently for many conclusions to be drawn.
Some work has been done on the factors affecting the accuracy of the assay of Chinese bismuthite, and the comparative results obtained by various methods of assay. Methods for the estimation of metallic impurities in tinned foods have also been studied and an improved method worked out. Experiments have also been made on the application of electrical conductivity methods to problems connected with the analysis of foods.
SAMPLING.
The sampling and analysis of consignments of metals, ores and oils for local export firms was, of course, affected by the strike, but in spite of the unfavourable conditions a considerable amount of this work was done. The following Table shows the amount of sampling done by the Government sampler during the past year :-
Anise Oil 1,262 Containers Antimony 1,227 slabs 101,655 Antimony ore 1,100 670 19 Bismuthite 12 2 Cassia Oil 1,458 12,937 " 3,800 Tons Manganese ore 7,300 tons Nickel bar 50 Spelter Tin 15,932 con-tainer Tin slag Wolfram Wood Oil Lard Limestone 50 tons 3,477 bags