Cyclic voltammetry has been applied to the study of a simple charge transfer reaction at a spherical electrode such as the static mercury drop electrode. Theoretical and experimental curves have been obtained at constant sphericity both for a reversible and slow electrode process, taking into account amalgam formation. The use of constant sphericity lends great advantages since, on the one hand it allows us to discriminate between kinetic and curvature effects? and on the other reduces the interference from uncompensated IR drop. Methods for evaluating heterogeneous kinetic parameters are also proposed.