M (1) 48
pentoxide. Any rice yielding 0.4% or over of Phosphorus pentoxide is held to be safe from the beri-beri point of view. None of the white polished rices came up to this standard, though No. 2 Saigon Round Rice yielded 0.33% P2O5. All the brown rices passed easily, Brown Seemin rice yielding 0.67%. Samples of New Territory padi of the white unpolished type yielded 0.47%. The preparation of Vitamine B Extract for the treatment of beri-beri is at present under consideration.
Some work was also carried out on the complete analysis of Bismuthite, an ore exported in considerable quantities from Hong Kong and in which the determination of some of the impurities is a matter of great commercial importance, especially traces of tungsten, molybdenum and tellurium.
A modified method for determining the phosphorus in manganese ores was also worked out.
SAMPLING
The following sampling of ores, metals, oils etc. was done by the Laboratory sampler during the year :-
Tin 24,200 ingots Antimony metal 120 cases Antimony ore 50 cases Wood oil 29,633 containers Cassia oil 145 cases Anise oil 417 cases Bismuth ore 18 cases Tea-seed oil 1 tank Bleaching powder 60 drums Lard 3,656 cases Tallow 74 casks Wolframite 10,860 tons Manganese ore 3,752 bags Paraffin wax 250 cases Coal 1 lot Condensed milk 39 casesMISCELLANEOUS SERVICES
In June, 1927, the assistance of the Laboratory was requested in dealing with insects in the herbarium of the Botanical and Forestry Department. It was therefore fumigated with prussic acid gas for 24 hours. The Superintendent reports that since then no insects have been observed among the books, plant specimens or in the room treated.
The filling of balloons with hydrogen gas for the Royal Observatory was another matter to which attention was given. A simple method of generating hydrogen gas was selected and a suitable apparatus supplied. Micrometric measurements were also made of fused quartz threads for the suspensions of some of the Observatory instruments.