X-ray photographs of certain sodium salts of the fatty acids (soap curds) show lines due to reflections from planes with very wide spacings of the order 40 A.U. These planar spacing increase uniformly with the number of CH₂ groups in the molecule, indicating an effective length of 1.25 A.U. for the CH₂ group. These and other lines can be accounted for by assuming that the curds are in the smectic state described by Friedel.