By neglecting the relaxation effect in concentrated solutions, it is shown that ionic mobilities determined from ionic self-diffusion coefficients give a consistent interpretation of conduction and diffusion measurements. Ionic hydration is assumed and is found to lead to hydration numbers which are reasonably constant over wide ranges of concentration and are consistent with the known behavior of the ions concerned. Where ionic hydration occurs, it should affect transport numbers, and the corresponding relationship is derived and applied. Empirically determined electrophoretic factors agree with those calculated by the Onsager-Fuoss model up to the highest concentrations for neutral salts and only fail for the highest concentrations of HCl. The values of a which must be assumed can be used for accurate calculation of equivalent conductivities in dilute solutions.