GRINDING, or TRITURATION, the act of breaking or comminuting a solid body, and reducing it into powder. See PULVERISATION and LEVIGATION.
The painters colours are grinded on a marble or porphyry, either with oil or gum-water.
GRINDING is also used for rubbing or wearing off the irregular parts of the surface of a body, and reducing it to the destined figure, whether that be flat, concave, or the like.
The grinding and polishing of glass is a considerable art; for which see GLASS-Grinding. For the grinding of optical glasses, see OPTICS, the Mechanical Part.