The fundamentals and most important experimental features of the elect
ric surface potentials of liquid solvents and solutions are briefly su
rveyed. Both aqueous and nonaqueous media are considered. The adsorbed
: Gibbs and Langmuir surface layers at the free surface of water, and
the influence of surface active and inorganic ions are considered. The
principles of the voltaic methods of measurement of the surface poten
tial shift are presented.