Surface Tension of Mercury

Abstract

Consistent values for the surface tension of mercury in a high vacuum (air pressure less than 1.2×${10}^{-5\mathrm{}}$ mm Hg throughout the period of experimentation), ranging from 438.4±0.3 dynes per cm at 12.5°C to 423.9±0.6 dynes per cm at 67°C, have been found by a modified flat-drop method. In evaluating them Worthington's equation $\sigma =\frac{{\mathrm{}(K-k)\mathrm{}}^2\rho }{2} . \frac{1.641 L}{1.641 L+(K-k)\mathrm{}}$ was used. The temperature gradient, determined from the best mean straight line through the experimental points, is 0.3015 dyne per cm per degree. Hence the average value of $k$, in the ? relation, was found to be 1.82. Reproduction of concordant results at intervals during a period of four months affords ample evidence of the thorough outgassing of the apparatus and is attributed to the great care used in securing relative perfection of details.