It contains a rich plant adhesive composition and has a strong adsorption effect, as well as a dissolved and oxidized effect on exotics such as unincorporated hair, grain shells, wood slag, sand and metal crumbs. The frequent use of black wood ears helps to clean digestive tracts and gastricate. In particular, workers engaged in heavy air pollution such as ore mining, metallurgical, cement manufacturing, hairdressing, flour processing, cotton swirling, etc., often eat black wood in good health。