1. J. Cl. Maxwell, Cambridge Calendar 1869; Phil. Mag. Bd. 48, S. 151. 1899.
2. M. Faraday, Exp. Untersuchungen §§ 1164, 1338, 1679.
3. W. Thomson, Cambr. and Dubl. Math. Journ. Nov. 1845, Papers on Electr. and Magn. §43f.
4. F. C. Mossotti, Arch, des sciences phys. (Genève) Bd. 6, S. 193. 1847.
5. H. Poincaré, Électr. et Optique 2. Aufl., §§ 45ff