THE SURFACE TENSION OF LIQUID HELIUM I AND THE LAW OF CORRESPONDING STATES

Measurements have been made by determining the force necessary to break the liquid film between the edge of a suspended metal ring and the liquid surface. The results obtained are about 13% larger than those given by Allen and Misener (1938), and the variation of the surface tension, γ, with temperature T fits quite well the equation γ = 0.600 (1 − T/Tc)1.04 dyne cm−1, where Tc is the critical temperature. Comparison with other liquids has been made following de Boer's formulation of the law of corresponding states, and the reduced equation γ = (γ0*/Tc*n) (Tc* − T*)n describes the results, (γ0*/Tc*n) and n being functions of the quantum parameter Λ*; the classical limit of (γ0*/Tc*n) is found by extrapolation to be 2.2.