By some old statutes of Edward M, Henry VIII, and Edward VI, the exportation of all metals was prohibited. Lead and tin were alone excepted probably on account of the great abundance of those metals, in the exportation of which a considerable part of the trade of the kingdom in those days consisted.

For the encouragement of the mining trade, the 5th of William and Mary, c. 17, exempted from the prohibition iron, copper, and mundic metal made from British ore. The exportation of all sorts of copper bars, foreign as well as British, was afterwards permitted by the 9th and 10th of William III, c. 26. The exportation of unmanufactured brass, of what is called gun-metal, bell-metal, and shroff-metal, still continues to be prohibited. Brass manufactures of all sorts may be exported duty free.