A semi-empirical equation for the conductivity of concentrated electrolytic solutions is derived from the Debye-Hlickel-Onsager limiting law. The comparison of this equation with experiment shuws agreement within a few per cent. or better, up to 4 to 5 N and in one case even up to 11 N.Measurements on NaNO, up to 4.85 N and K,Fe(CN), up to 2.96 N are reported. Details of the null-point detector and the variable-frequency oscillator used in the bridge circuit are also given.