OBSERVATIONS of the intensity and polarization of scattered solar radiation from Venus, coupled with numerical solutions to the radiative transfer equation, have in recent years fairly well defined the optical properties of the clouds of Venus. By fitting calculations of the variation of intensity of scattered light with phase angle to the phase curve of Venus, Arking and Potter1 have shown that the scattering particles are highly transparent with a refractive index between 1.3 and 1.7 in the visible spectrum. Analysis of polarization observations by Coffeen2 has further narrowed the possible range of the refractive index to between 1.43 and 1.55. Most recently, comparison of the polarization observations with exact numerical solutions to the radiative transfer equation, taking both multiple scattering and polarization into account (J. E. Hansen, private communication) has shown that the refractive index of the scattering material in the Venusian clouds should be 1.450±0.015 at the wavelength λ= 5500 A. The comparison has further shown that the scatterers are spherical particles approximately 1 µm in radius. This sphericity strongly suggests that the particles are liquid.