The study of the temperature-dependent phase equilibria of dilute solutions has been of interest to thermodynamicists over the last several decades. Oneway of studying this behavior is through the use of partial molar excess enthalpies at infinite dilution, hE. Recently a sizable body of accurate data nonionic solutions has begun to appear in the literature. 1 Such results are complimentary to limiting activitycoefficients, y; RT In y is a measure of the excess Gibbs free energy for solute—solvent interactions in the mixture, and hE represents the corresponding enthalpy. Physically, AE” is the enthalpy, on a molar basis, associated with removing a single solute molecule from a reference state of pure solute and placing it in a solvent at infinite dilution. The experimental methods for obtaining such data are reviewed by Fuchs and Stephenson et al., la-lj and by Trampe and Eckert. lk