The escape of molecules from a plane surface into a still atmosphere

Abstract

Abstract When molecules escape from solids or liquids into a gaseous atmosphere, they do so at a rate which is governed by certain inherent properties of the condensed systems and by the relative values of the saturation pressure of the condensate and the total pressure of the atmosphere. Present considerations are restricted to systems where in the saturation pressure is a small fraction of the ambient pressure, and to liquids evaporating from plane surfaces. A theory is advanced which embraces the diffusion conditions formulated by Maxwell (1890) and the vacuum conditions investigated by Knudsen (1915), and is cast in such a form as to make accessible to experiment the determination of the coefficients of diffusion and accommodation by novel means.