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Joseph Howard McCarthy

Publications and source records attributed to Joseph Howard McCarthy.

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Mercury in soil gas and air--A potential tool in mineral exploration

The mercury content in soil gas and in the atmosphere was measured in several mining districts to test the possibility that the mercury content in the atmosphere is higher over ore deposits than over barren ground. At Cortez, Nev., the distribution of anorhalous amounts of mercury in the air collected at ground level (soil gas) correlates well with the distribution of gold-bearing rocks that are covered by as much as 100 feet of gravel. The mercury content in the atmosphere collected at an altitude of 200 feet by an aircraft was 20 times background over a mercury posit and 10 times background over two porphyry copper deposits. Measurement of mercury in soil gas and air may prove to be a valuable exploration tool.

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Density comparison method for the measurement of isotopic variations in prepared waters

The falling-drop method of density determination has been modified so that the densities of a standard and a sample water are compared simultaneously. A constant temperature bath that does not vary more than 0.0001°C and an accurate double micropipet are described. The method has sufficient sensitivity and precision to distinguish waters that differ in specific gravity by 0.025 micrograms per ml. The method could be applied to the measurement of small variations in the isotopic composition of prepared waters.

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