LI.Some remarks on the analogy of certain cases of propagation of electromagnetic waves and the motion of a particle in a potential field

Summary In §§ 2–6 the conditions are investigated for which a wave-equation of the type may he such that a group of waves moves as a mass-point in a field of force which is independent of the frequency of the group. This leads to either the relativistic or the non- relativistic Schrödinger-equation for the dependence of u on ω.