The behaviour of rare gases in metals has been studied quite frequently : n the past. The migration of the rare gas atoms was shown to be a very complex phenomenon, which could satisfactorily be described in a system of release stages1similar to the recovery stages in quenched or irradiated metals. The most studied metal is probably silver2,3but Cu4–11and Pt4, 12–14have also been investigated. It is the purpose of the present note to communicate some new results for Cu and Pt, and to indicate some common features of the three metals.