The popular statistical theory of absolute diffuse reflectance of powders put forth by Melamed [J. Appl. Phys. 34, 560-570 (1963)] a quarter century ago has been re-examined thoroughly. Substantial errors in the physical formulation of the theory have been found and a corrected version is being presented. Some of Melamed's data fits to the theory are also re-examined in the light of the corrected theoretical model.