Аннотация:It is shown that there is complete agreement between values of specific adsorption obtained by differentiating the two-dimensional pressure with respect to the logarithm of concentration and those obtained from the potential shift caused by adding the active component to the solution at epsilon equals const when the specific adsorption of cesium on Hg from dimethylformamide (DMF) is studied by the mixed-electrolyte method provided the reference ion Na plus is not surface active. It is shown that a virial isotherm which accounts for the buffer action of the electric double layer yields a good description of Cs** plus ion adsorption from DMF on Hg.