Using the synthetic soap cetyl pyridinium chloride the effects of added chlorobenzene and sodium chloride upon various physical properties, such as saturation solubilities, viscosity, osmotic pressure, sedimentation velocity, and interfacial tension, have been quantitatively measured. The results suggest that the soap micelle has a very labile structure, the approximately spherical aggregates present in pure soap solutions changing to more asymmetric shapes in the presence of suitable concentrations of sodium chloride and chlorobenzene.