2227a.     ---------------.  [MCCARTNEY, J. T., AND ANDERSON, R. B.]  Electron Microscopic Replica Studies of Porosity in Fused-Iron Catalyst.  Jour. Appl. Phys., vol. 22, 1951, pp. 1441-1443; Chem. Abs., vol. 46, 1952, p. 4339.

          Preparation of various replicas of a fused-Fe (Fe₃O₄-MgO-K₂O) synthetic NH₃ catalyst is described.  Micrographs of these replicas show comparable fine structures that are attributed to the pores developed in the catalyst upon reduction.  Dimensions of these fine structures compare reasonably well with pore diameters calculated from pore volume-surface area determination.