Previous work J-133 Quarterly Report No. 2 has established the eclectrochemical activity of metallic sodium. Recent work has been concentrated on improvement of the electrochemical utilization Faraday efficiency of the sodium electrode in aqueous electrolytes. The apparent increase in Faraday efficiency with current drain is due to the use of a constant rate of extrusion at all loads. Steady drains were obtained at all loads tested indicating that a minimum extrusion rate corresponding to maximum Faraday efficiency has not been attained.