Densities of aqueous solutions of disodium tartrate at the molalities (0.09996, 0.49097, and 0.9649) mol (.) k(-1) and of dipotassium L-tartrate at the molalities (0.09993, 0.49769, and 0.9912) mol (.) kg(-1) were determined at 1 K temperature intervals from T = 278.15 K to T = 343.15 K. The densities were used to determine the apparent molar volumes, cubic expansion coefficients, the apparent molar expansibilities, and the second derivatives of the volume with respect to temperature which are related to the derivatives of isobaric heat capacities with respect to pressure.