. . "le group, Y is the same as X or oxygen, and M is either a metal or non-metal of the groups of the Periodic Table including silicon other than Groups IA, IIA, VIIA and O, m is a number up to 8 and n is zero or a number less than 8, or an inorganic ionic compound containing M and Y, (2) bringing about the condensation and polymerization of the hydrolyzed compounds and (3) calcining the polymerized p" . . . .