  We propose a method to calculate dispersion interactions in a system composed
of a one dimensional layering of finite thickness anisotropic and optically
active slabs. The result is expressed within the algebra of 4x4 matrices and is
demonstrated to be equivalent to the known limits of isotropic, nonretarded and
uniaxial dispersion interactions. The method is also capable of handling
dielectric media with smoothly varying anisotropy axes.
