On the Dielectric Problem of Isotrophic Sphere in Anisotropic Medium

The electrostatic problem of isotropic sphere in anisotropic background medium is treated. It will be shown that the internal field and dipole moment of the sphere cannot be calculated using the same shape effects as in the case for isotropic background. The result makes it necessary to rewrite mixing formulas that appear in the literature for anisotropic heterogeneous media.