Molecular susceptibility. The determination of molar Cotton-Mouton constants of solutes at infinite dilution

Abstract

The construction and testing of apparatus for the measurement of magnetic birefringences of liquids are described. An equation is developed whereby specific and molar Cotton-Mouton constants of solutes may be obtained at infinite dilution from the magnetic double refractions, densities, and refractive indices of solutions of known concentrations. The results, when considered in conjunction with mean susceptibilities from the literature and principal polarizabilities available via the Kerr effect, can lead to specifications of molecular susceptibility ellipsoids for the dissolved species. Nine solutes are now examined. For three of these the principal susceptibilities have been previously recorded by the Krishnan-Lonsdale techniques applied to crystals. The satisfactory agreement between past and present values is held to justify the investigation as solutes of liquids and other substances which, for various reasons, cannot be studied by the "crystal" method.