Abstract
The complex dielectric constants of three compositions of trimethylpentane and nitrobenzene have been measured as a function of temperature for a range near the consolute temperature. The frequency employed was 3300 Mc/sec. The experimental procedure involved the study of the standing wave established in a coaxial line. The chemical systems showed maxima in both the real and imaginary parts of the complex dielectric constant at temperatures above those at which phase separation occurs. The finding of Semenchenko and Azimov is thus confirmed. A discussion of the validity of applying thermodynamic formulae to dielectrics showing loss is given and some qualitative remarks are offered concerning the change of the systems as they are cooled. These remarks are based upon the effect of the applied field upon the entropy of the solutions.