A.c. measurements on several alkali berate glasses were made at high temperatures. It was suggested that the positive-ion depleted region (PDR) which develops near the temporary anode during each halfcycle is an electric double layer formed by uncompensated negatively charged species and their mirror image and that, as an applied voltage increases, conduction of the electrons and/or negatively charged ionic species in the PDR as well as field-assisted injection of the gold ions from the gold anode take place.