Two different electrode systems are found. One is the system in which the gold surface is covered with a hydrated monolayer of adsorbed oxygen atoms. Here, the rest potential is a mixed potential, . The other is the system in which the gold surface is covered with a multilayer of hydrated . In this case, the rest potential is an equilibrium metal‐metal oxide potential, . The electrical properties of the Au‐O layer are such that the reaction proceeds with great difficulty on it, and the reversible value of 1230 mv is not expected to be observed on gold electrodes.