The influence of various cations on the catalytic properties of clays.

Polymerization of alanine adenylate in the presence of various clays in their Na form gave increasing degrees of polymerization in the following order: montmorillonite less than nontronite less than hectorite. With montmorillonite, presaturated with different cations the order was: Mg less Ca less than Fe less than Al less than Na. From all these clays, hectorite was the only one to enable also some polymerization of lysine.