We have measured the spectrum and polarization of light scattered by fluctuations in the isotropic phase of the nematic liquid crystal p-methoxy benzylidene p-n-butylanilene. The magnetic biréfringence and the intensity of the scattered light both diverge as (T- T*c)-1 where T*c is 1 °K below the phase transition temperature. The scattered light polarized parallel to the incident light has a Lorentzian spectrum of width Ɖ that varies as (T- T*c)/v. We have determined the transport coefficient v and find it has the same temperature dependence as the shear viscosity. The spectrum of the depolarized scattered light shows evidence of coupling between the order parameter and thermally excited shear waves. We determine the coupling coefficient ν and find it shows an anomalous increase in the 5 °C above the phase transition temperature. The phenomenological theory of de Gennes is consistent with our results and we give numerical values for the parameters in his theory