Charcoal made from hard wood was good for fuel, from soft wood good to clarify liquids or make crayons or gunpowder. Blacksmiths used chestnut charcoal, holly with bark charcoal was "believed to render iron brittle." Charcoal powder was used as a poultice for ulcers or tooth-powder. Areca nut charcoal powder was "the most fashionable dentifrice."