The electrocapillary equations and their application to solid electrodes are reviewed. Evidence is presented showing that solid electrodes exhibit two kinds of electrocapillary properties. For plastic deformation or immersion processes, thermodynamic properties of the solid electrodes are consistent with the classical Lippmann equation. For elastic processes, thermodynamic properties are inter-related by; the Gokhshtein equation that accounts for the influence of elastic strain on a solid electrode's charge density. The latter equation predicts the difference between the potential of zero charge and the potential of the maximum ni the electrocapillary curve. For solid metals, the presence of the electronic dipole layer is the primary reason for the difference between these two points.