Based on the 1967 work of Delmastro and Smith, a study has been carried out of the effect of sphericity on current-time relationships at potentiostatted electrodes. The study embraces all degrees of reversibility, does not assume equal diffusion coefficients and covers instances in which the reduction product dissolves in the electrolyte solution or in the electrode. It has implications for all polarographic techniques, particularly those that employ the static mercury drop electrode. The effect of electrode sphericity is examined in detail for cases of polarographic reductions to amalgamable metals and it is demonstrated that the customary plots of ln(id-i)/i versus potential are without quantitative significance (except when the reduction is reversible and the sphericity is negligible). Alternative logarithmic plots are suggested that are accurately linear under all circumstances and from which exact thermodynamic and/or kinetic parameters may be obtained.