Six determinations have been made of the half-life of polonium with four different steady-state, resistance-bridge calorimeters and five different samples of polonium. These six values of the half-life have been weighted and combined to give a grand-mean value of the half-life of 138.4005±0.0051 days (internal consistency) or ±0.0058 day (external consistency).

• Received 14 May 1953

DOI:https://doi.org/10.1103/PhysRev.96.719