ELECTRODE OF THE SECOND KIND2

"The assembly consists of a metal, in contact with a slightly soluble salt of this metal, immersed in a solution containing the same anion as that of the metal salt (e.g., silver---silver chloride---potassium chloride solution). The potential of the metal is controlled by the concentration of its cation in the solution, but this, in turn, is controlled by the anion concentration in the solution through the solubility product of the slightly soluble metal salt. "