As a part of our calorimetric studies, we have measured the excess molar enthalpies of the ternary system {(x(1))propyl propanoate + (x(2))1-hexanol + (1 - x(1) - x(2))benzene} and of their corresponding binary mixtures at 25 degreesC and 35 degreesC and atmospheric pressure, over the whole composition range. The excess molar enthalpies were obtained by means of a Calvet microcalorimeter. The excess molar enthalpies for the binary mixtures were fitted to a Redlich-Kister variable-degree polynomial, and the ternary excess molar enthalpies were adequately correlated by the Cibulka equation. The results obtained for the ternary mixture were used to test the empirical methods of Kohler; Jacob and Fitzner; Colinet; Tsao and Smith; Toop; Scatchard et al.; and Hillert. These methods predict excess properties of the ternary mixtures from those of the involved binary mixtures.