Electrochemical studies in the temperature range 600-700 C are reported for Au, Pt, Ag, Ni, and a noble metal alloy, Au-20% pd in the ternary carbonate eutectic mixture, using the potentiostatic polarization method. Referred to a Ag/Ag(+) reference half cell, the steady-state or corrosion potentials for this series of metals at 600 C are: Au-pd, -430 mv, Au, -470 mv, Pt. -475 mv, Ag, -680 mv, and Ni, -1166 mv. For Ni at 600 C the anodic potentiostatic polarization curve is characteristic of metal passivation; a primary passive potential is found at -1015+ 5 mv, but the protection conferred appears far from complete. Further data are reported to contribute to the nature of the anodic and cathodic processes in molten carbonate electrolyses. The phenomenon of carbon deposition at the cathode is reported and examined in light of thermodynamic free energy calculations.