Correction terms are derived for the polarizability of a dielectric sphere
and Maxwell Garnett mixing formula. The correction terms take into account
the size of the scatterers, and therefore depend on the frequency of the in
cident field. However, the limitation of the mixing rule result is that the
volume fraction of the inclusions has to be small. The imaginary part of t
he effective permittivity is shown to be consistent with the extinction due
to scattering by small inclusions. (C) 1999 John Wiley & Sons, Inc.