Investigation of the physical and chemical properties of polonium important to its behavior and for the improvement of the quantity and quality produced is being continued. A sample of polonium is approximatelyf 1 x 10{sup 9} disintegrations per minute was counted in a Logac for 250 days in order to determine the half life. A statistical treatment of the results gave a half life of 138.3562 {+-} 0.446 days. Combined with previous calorimetric determinations a new grand mean of 138.3975 {+-} 0.0091 days resulted. The wavelengths of 138 lines appearing in the spark spectrum between 3050A and 3463A (Region 4) have been tentatively assigned to polonium and have a probable error of less than 0.02A. Thirty six lines in Region 6 (4225A to 5675A) tentatively assigned to polonium have a probable error of less than D D6A. A measurement of the resistivity of polonium has given a value of about 95 microohm centimeters, and although the Hall voltage could not be measured with much precision, it was possible to set a maximum value of 0.03 millivolt. These values indicate the polonium is a metallic conductor rather than a semiconductor. A rugged but compact gauge made of stainless steel with a …

Two approaches to lithium isotope separation have been followed in this research and are described and compared. One is electrolysis in non-aqueous systems at high cathode efficiency. The other is electrolysis in aqueous systems with anode depolarizers.