Abstract :
Hubert H. Race (General Electric Company, Schenectady, N. Y.): The flat portion called region B (figure 1) of the conductance-time curve for insulating liquids has always puzzled me. The authors state that “region C represents the time during which the ions are swept out of the space between the electrodes and space charges built up in the spaces near the electrodes”. It seems to me that this statement must also apply to region B because certainly the current carriers are ions. Therefore, if we assume that on the average the charge per ion is constant, we must have conditions such that in region B the number of ions remains constant while in region C the number of ions is gradually decreased. From his work on nonaqueous solutions, Doctor R. M. Fuoss of our laboratory suggests the explanation that in the region B there is an equilibrium between associated and dissociated ions so that new ions are formed by dissociation as fast as they are swept out by the field. When the supply of undis-sociated ions is exhausted, however, further current flow decreases the ion concentration and the current decreases as in region C. The mathematical form of this time dependence is given by Doctor Fuoss as follows:
