Boletus fomentarius, Linn.—Another indigenous fungus, found on the oak, birch, and other trees. Its uses are similar to the preceding, and it might, with more propriety, be called Agaric of the Oak, or Surgeon's Agaric. The substance sold in the shops as Amadou, or German tinder, is prepared from this, as well as the preceding species, by cutting the fungus in slices, beating it, and then soaking it in a solution of nitre, and afterwards drying it. When impregnated with gunpowder it is called black amadou. Amadou, or German tinder, has been recommended by Mr.Wetherfield [Lond. Med. Gaz. Nov. 26, 1841, p. 337.] as an elastic medium for applying support and pressure, and as a defence to tender and delicate parts; as in the form of a graduated compress, in umbilical hernia of newborn infants, and as a compress over fistulous ulcers of the groin. It does not lose its elasticity, like lint.