. . . "eriodic Table of the Elements, in which a is a number ranging from about 0.1 to about 15, b is a number ranging from 0to about 15, c is a number ranging from about 1 to about 25 and d is a number ranging from about 2.1 to about 55, in which M, M' and Ti are present in said titanate in their most stable oxidation state and O is in stoichiometric balance with M, M' and Tisuch that the metal titanate" .