The static dielectric constants of n-butyl alcohol, t-butyl alcohol, n-butyl chloride, n-butyl bromide, t-butyl chloride, and water were experimentally determined over a temperature range of 14° to 50°C and over a pressure range of 1 to 200 atmos. In addition, for glycerol, both the static dielectric constant from −18° to 14°C and the dielectric relaxation data at 0°C and up to 1.5 mc were obtained over the same pressure interval. The theory of dielectric polarization was then applied to these measurements to determine the molecular interaction. On the basis of the molecular interaction, structures and structure changes with temperature and pressure have been proposed for the various liquids studied.