Ultrasonic vibration potentials (uvp) are alternating potential differences which arise when sound waves are propagated through electrolytic solutions. The amplitude of the uvp depends on the masses of the hydrated ions which in turn are related to their partial molal volumes. 200‐kHz pulse‐modulated ultrasonic waves were used for the measurement of the uvp's of uni‐univalent electrolytes in methanol, ethanol, and dimethylformamide (DMF). Uvp's were found to depend little on concentration in the range 3.10−4‐3.10−2Mfor nitrates and chlorides, but showed small decreases for bromides and large decreases for iodides. The amplitudes of the measured uvp's were strongly dependent on the nature of the electrolyte and of the solvent. The uvp data were combined to data of partial molal volume of electrolytes to yield the partial molal volumes V̄10of monovalent ions in methanol, ethanol, and DMF. Hepler's equation was used to split the V̄10's into their geometric and electrostrictive contributions. It was found that the geometric contribution depends essentially on the packing of the solvent molecules about ions. The electrostrictive contribution appeared to be mostly dependent on the nature of the content of the layer of atoms, 3–4 Å thick, in contact with the ion.