  We derive an expression for the static dielectric constant of the colloidal
susp ensions based on the electrokinetic equations. The analysis assumes that
the ions have the same diffusivity, and that the double layer is much thinner
than the radius of curvature of the particles. It is shown that the dielectric
increment of the double layer polarization mechanism is originated from the
free energy stored in the salt concentration inhomogeniety. We also show that
the dominant polarization charges in the theory are at the electrodes, rather
than close to the particles.
