Every electrokinetic process is necessarily accompanied by an electric process which, in certain circumstances, can produce an important deviation in measured values of flows in relation to the expected values. In this work it is shown how the phenomenological equations are affected by the electromotive force (e. m. f.), e, of the electrochemical cell, generated in the system by electrolytic decomposition, and by the process of electric purification. The former modifies one of the generalized forces, while the latter alters the values of the phenomenological coefficients.