Isotropy in the Electromagnetic Field

In Part III of his 1861 paper “On Physical Lines of Force”, James Clerk Maxwell introduces the concept of displacement current in connection with the elasticity of the medium for the propagation of light. During the course of Part III, the luminiferous medium changes from an an-isotropic sea of molecular vortices into an isotropic dielectric solid. An attempt will be made to reconcile these two seemingly contradictory mediums.