Superposition rule for the magneto-optic effects in isotropic media

The superposition rule for magneto-optic effects is presented. This rule could be treated as a generalization of Faraday and Cotton-Mouton effects for any orientation of external magnetic field with regard to the light wave propagation direction and was obtained without any restrictions about the components of the dielectric tensor. The formulae for total birefringence in an isotropic medium placed within magnetic field with any orientation has been given. This superposition rule let us also measure two magneto-optic constants simultaneously.