Powder

Powder (through O. Fr. puldre, modern poudre, from Lat. pulvis, pulveris, dust), the small loose particles into which solid matter is disintegrated by such processes as grinding, crushing, pounding, &c., hence any preparation which takes the form of such loose uncompacted particles, the most familiar example of such preparation being that of gunpowder. Many powders are found in medical uses, some of which have retained the name of their inventor, such as the compound powder of rhubarb, "Gregory powder," named after a Scottish doctor, James Gregory (1758-1822). Various preparations in form of powder are used for toilet purposes. During the period when the hair or wig was worn "powdered" or whitened, houses had a special room set apart for the process, known as the powdering-room or closet. In some birds, such as the herons, certain down-feathers or plumulae break off into a fine dust as fast as they are formed and form tracts defined in size and situation and known as "powder-down patches."