3460.     TROPSCH, H., AND SCHELLENBERG, A.  [Formation of Methane in the Water-Gas Process.]  Brennstoff-Chem., vol. 3, 1922, pp. 33-37; Ges. Abhandl. Kenntnis Kohle, vol. 6, 1921, pp. 317-329; Chem. Abs., vol. 16, 1922, p. 2022.

        Vignon’s experiments (abs. 3560, 3561, 3562, 3563), on the reduction of CO to CH₄ by means of H₂ in the presence of CaO and Fe, at 900°-1,000° have been repeated and only traces of CH₄ found.  The presence of 25-30% CH₄ among the products of dry distillation of Ca(HCOO)₂ could likewise not be confirmed.  Vignon apparently determined CH₄ by difference and did not allow for residual N₂ in the apparatus.