2925.     ---------------.  [RUFF, O., AND GERSTEN, E.]  [Carbides of Manganese and Nickel.]  Ber. deut. chem. Gesell., vol. 46, 1913, pp. 400-413; Chem. Abs., vol. 7, 1913, p. 1848.

        Molecular heats of formation of Mn3C=-12.92.14, Fe3C=-15.30.2 and Ni3C=-39410 cal.  The Ni3C is very unstable and is not obtained in a pure condition.  Mn3C is comparatively stable and is obtained by heating Mn in a C crucible with C at 1,600 in an electric vacuum furnace.  Ni3C is formed at 2,100.  The maximum amount of C found in the carbide is 6.42%.