Abstract: An analytical treatment is given for the scattering of light, neutron and electron beams in the presence and absence of an external applied electro-static field by a system for which the charge transport can be described by the D-H equation. The resulting scatterings are shown to be quasi-elastic, i.e., Rayleigh scattering. When there is no external field, the spectral distribution of the Rayleigll scattering consists of two superposed central peaks of different widths, their shapes being assymmetric. The application of an external static electric field would give rise to variation of width and location of these Rayleigh peaks. The possibility of observing the above mentioned phenomena is also discussed.