Some time ago Fournier et al1showed that the “mirage effect”2[the deflection of a light beam by refractive index (n) gradients in a fluid above a heated surface] was two orders of magnitude greater when the fluid was a liquid than when it was a gas. The larger beam deflections arose because of the larger dn/dT changes found with liquids than with gases. Advantage has been taken of this higher sensitivity in a variety of nonspectroscopic and spectroscopic studies (in the visible region of the spectrum) of solids submerged in liquids, and recently Palmer and Smith3, 4and also Varlashkin and Low5have extended the spectral measurements into the infrared (IR) range; IR Fourier transform (FT) spectra of solids submerged in CC14were obtained.