Expressions for the interaction potential energy as well as Coulomb's force between a pair of charges, placed in anisotropic medium, are obtained. The procedure reveals the basic correctness of Maxwell's field concept of electromagnetism. The result is shown to be of practical application in calculating the binding, energies and wave functions of electron or hole impurity states (1,2) as well as that of excitons (3,4) in anisotropic crystals.