A study has been made of the infra-red dispersion of the magnetic double refraction—Cotton-Mouton effect—in the wave-length region from λ = 0.650µ to 1.6µ of the following liquids: nitrobenzene, chlorobenzene, carbon disulfide, halowax oil, o-nitrotoluene, benzene and toluene. Ratios of the observed double refraction to the electric double refraction are shown to be constant within experimental error. Comparison of observed dispersion curves with calculated curves from Havelock's law is also shown to fit for the most part within experimental error. This indicates that the magnetic and optical anisotropics of the molecules are relatively independent of the wave-length. The deviation of Havelock's curve from the observed curves in general indicate that Havelock values for short wave-lengths are too high, and for long wave-lengths too low. The deviations shown for the liquids tried are greatest for benzene, where for long wave-lengths the difference amounts to about 5 percent.
FRANCIS J. DAVIS, "The Dispersion of Magnetic Double Refraction in the Short Infra-Red Spectrum," J. Opt. Soc. Am. 30, 488-494 (1940)