The author points out that Arrhenius‘s theory of partial electrolytic dissociation was immaturely displaced about eight decades ago by the empirical concept of ionic activities and the assumption of complete dissociation of electrolytes at all concentrations. The latter gradually amounted to converting the theory of electrolytes into a highly complicated set of parametrically extended Debye-Huckel equations without any physical significance. Therefore, the author abandoned the existing theory and undertook a systematic investigation of the available experimental data. Over the recent decades, the author could completely quantitatively restore the original theory of partial dissociation for all concentrations. Now solution properties can be easily explained through simple mathematical equations with absolute concentrations and volumes of ions and ion pairs and surface and bulk hydration numbers.