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have been determined by both Whitehorn's and also by Smirk's method, but chief reliance has been placed on a method worked out in this Laboratory of determining admixture of seawater by means of the electrical conductivity. Osmotic requirements of the body necessitate the maintenance of the concentration of electrolytes within comparatively narrow limits and variations in most of the organic constituents of bodily fluids have no effect on the conductivity. The admixture of 5% of seawater with blood will give an increase in the conductivity figure of about 2,000 reciprocal megohms.
A modification of the ortho-tolidine method is being worked out for the determination of total chlorine in a single drop of blood. In cases of supposed drowning, where it is of great importance to know the relative concentrations of chlorine in the right and left heart, such a method would be invaluable.
A certain amount of work was also carried out on the determination of minute amounts of chlorine in acid for the batteries of submarines. Specifications for such acid require the chlorine percentage to be not greater than 0.0005%. Accurate determinations of such amounts are not easy without special apparatus and exceptionally pure reagents.
SAMPLING.
The following Table gives the amount of sampling of commercial products carried out by the Government sampler during the year.
The amount of Chinese ingot tin sampled during the year as will be seen below amounted to over 4,000 tons or nearly 14 tons per working day. This in itself means the sampling of an average of 280 ingots and the placing of the Government stamp on each, per day.
Substance. 1929, 1928. Tin 4,119 tons. 1,965 tons. Wolfram ore 364 2,185 lbs. 42 19 7,500 lbs. Bismuth ore None. Lead ore 51 tons. Solder 770 lbs. Manganese ore 465 tons. Copper coins None. Portland cement 8,000 lbs. Wood Oil 5,209 lbs. 15,120 lbs. Anise Oil 43,330 lbs. Cassia Oil None. Tea seed Oil 80 tons. 414 tons. Lard 16,145 cases. Paraffin Wax 407 bags. 400 cases. Nitric Acid None. 470 tons. 2,150 bags. 39 cases.