Room Temperature Tarnishing of Silver in Bromine and lodine

Pure silver was tarnished in an atmosphere of iodine and bromine vapor at room temperature. This resulted in impervious halide surface layers, from which tarnishing rates could be deduced by means of a photomicrographic technique. It was found that the parabolic rate law, with diffusion being the rate‐determining step, also holds at room temperature. The presence of water vapor reduces the rate of halogenation by a factor of two.