Societies and Academies

Abstract

LONDON. Faraday Society, May 2.—Mr. James Swinburne, F.R.S., president, in the chair.—A. Scott-Hansen: Hydro-electric plants in Norway and their application to electrochemical industry (see p. 501).—Edgar Stansfleld: Two simple forms of gas-pressure regulators. The two regulators described give a steady pressure, easily adjusted, not influenced by the rate of flow of the gas. They consist merely of an outer containing vessel into which water is poured, and an inner cylinder open top and bottom containing a floating beaker to which a valve is connected. When gas is passed into the inner cylinder through the valve, the position of the floating beaker adjusts itself so that the pressure of gas rises until the valve just closes.—Dr. W. C. McC. Lewis: Internal, molecular, or intrinsic pressure-a survey of the various expressions proposed for its determination. If we consider an imaginary plane of unit area placed in any direction well inside a liquid mass, equilibrium across this plane is maintained by the balanced attractive and repulsive molecular forces, which we have reason to believe are of very great magnitude, amounting to hundreds, or even thousands, of atmospheres. The attractive force per unit area is defined as the molecular, internal, or intrinsic pressure of the liquid, and is usually denoted by the symbol K. The present paper is a survey of the various attempts which have been made to estimate the value of K for various liquids.