COMPOSITE MATERIAL COMPRISING A MIXTURE IN DIVIDED FORM OF A CERAMIC BASE AND A LOW FUSING GLASS BONDING AGENT THEREFOR; A HOT PRESSED COMPOSITE INTEGRAL MATERIAL COMPRISING A CERAMIC BASE, THE PARTICLES OF WHICH ARE BONDED TOGETHER WITH A LOW FUSION POINT GLASS; SAID MATERIALS IN GENERAL BEING IN SHEET, BLOCK, SPECIAL SHAPES, AND BULK FORM