aqueous solutions of octyl phenoxy polyethoxy ethanol (triton x-114) show phase separation on standing and also in the presence of corn oil. the surface tension of varying concentrations of the upper phase of these systems decreases markedly at lower concentrations, tending to become constant at higher concentrations. the surface activity of this phase as observed from surface tension/concentration curves may be greater, less than or about the same as that of the corresponding upper phase concentration of the control which is a surfactant solution without the oil. results of this study indicate that the surface activity of the upper phase of triton x-114 solutions is not affected so much by the solubilization of corn oil but by the limit to which solubilization has occurred. the surface activity of this phase is much less than that of the lower phase of corresponding systems. however, the surface activity of the lower phase is not influenced by the solubilizate or solubilization of the oil. 13 refs