36.     ALMQUIST, J. A. and CRITTENDEN, E. D.  Study of Pure-Iron and Promoted-Iron Catalysts for Ammonia Synthesis.  Ind. Eng. Chem., vol. 18, 1926, pp. 1307-1309; Chem. Abs., vol. 21, 1927, p. 802.

               Several pure and promoted Fe catalysts are compared.  The activity of pure Fe depends upon the state of oxidation of the fused oxide from which it is obtained by reduction.  Fe₃O₄ gives the best results.  The addition of K₂O alone lowers the activity of pure Fe, but when SiO₂ is added also there is a promoting action.  It is shown that K₂O has a marked promoting action in the presence of difficulty reducible oxides of an acidic nature, for example, those of Mn. W, Si, and Al.  It is also shown that its addition to Fe containing oxides of metals closely related to Fe, such as those of Ni and Co, lowers the activity.

                ALTMAYER, V.  See abs. 2217, 2218, 2219.

               ALTSHULLER, S. B.  See abs. 784, 804.

               AMERO, R. C.  See abs. 432.