The black oak is one of the loftiest and most majestic trees of the forest. Its bark is strongly astringent, and is largely employed in tanning and dyeing. Its astringent properties suggest its use in diarrhoea, and as an injection in lax conditions of the mucous membrane of either intestines or other surface covered with this membrane. In relaxed uvula and sore-throat, and as an astringent wash in spongy granulations (proud flesh), hemorrhoids, etc., it has proven of value. The ground bark, incorporated in a poultice, has proven useful in gangrenous or mortified conditions. Baths of a decoction of oak-bark are valuable in weak children, whose lax condition is the result of debilitating disease.