The interfacial density profiles, pressure tensor, and Tolman-length ST are determined for the critical droplets of nonane in the framework of the semiempirical van der Waals/Cahn-Hilliard theory. It is shown that the Tolman＇s length is strongly size dependent, and tends to a negative value for large drops; indicating that Tolman＇s approximation for the curvature : dependence of the interfacial free-energy gamma approximate to gamma(infinity)/(1 + 2 delta(T,eq)/R) based on the equilibrium values delta(T,eq), and gamma(infinity), is inaccurate for typical liquid nuclei.