2850.     ---------------.  [ROELEN, O.]  [Preparation of Catalysts.]  FIAT Reel K-29, 1938, frames 7,189,-7,193; PB 70,218; TOM Reel 296.

        Review of the actual state of tests on the improvement in catalyst preparation in the form of an operating instruction for the preparation, especially of Th-free Co-Mg catalysts.  1 picture.