828.    EMMETT, P. H., AND CINES, M.  Surface-Area Measurements on Metal Spheres and Carbon Blacks.  Jour. Phys. and Colloid Chem., vol. 51, 1947, pp. 1329-1341; Chem. Abs., vol. 42, 1948, p. 1104.

     Comparison of areas obtained by adsorption isotherms for N₂ at 195° on metal powders with those calculated from photomicrographs yields roughness factors in the range 1.1-1.8.  Areas determined by the adsorption isotherms for CS₂ and for C₄H₁₀ are 20-50% lower than those obtained by using N₂ as adsorbate.  Pelletizing carbon black produces no appreciable changes in its surface area per gm.