TY - JOUR T1 - The Differential Equations of Fresnel's Polarisation-Vector, with an Extension to the Case of Active Media JF - Proceedings of the Royal Society of London (1854-1905) VL - 70 SP - 37 EP - 43 PY - 1902/01/01/ UR - http://dx.doi.org/10.1098/rspl.1902.0004 M3 - doi:10.1098/rspl.1902.0004 AU - Walker, J. ER -