(1) A type of adhesive or bonding agent that may be either inorganic or organic, soft, and workable when fresh but sets to a hard, infusible solid on standing, either by hydraulic action or by chemical cross-linking. The chief ingredients of inorganic mortars are cement, lime, silica, sulfur, and sodium or potassium silicate. Organic mortars are based on various synthetic resins (epoxy, phenolic, polyester, and furan). All types are resistant to acids. Some (potassium silicate) are useful up to 1600F. Others are used for bonding acid-proof brick, tile, etc.; for masonry construction; and for lining chemical reaction equipment.See Sealant; Adhesive; cement. (2) A ceramic receptacle used by pharmacists for preparing mixtures of medicinals and for hand-pulverizing soft solids.