A short encyclopedia entry defining mordants in dyeing as substances that prepare fabrics to take up coloring matter. It lists common mordants of the period, including alum (sulphat of alumine), cream of tartar, tin solutions, gallic acid, copper sulphate, verdigris, arsenic and zinc sulphate. It also gives an early 19th-century chemical explanation of how mordants act on the stuffs and on the pigment.