8. Gold obtained in any of these methods is always more or less alloyed with some other metal, especially with silver or copper; but a separation is produced, so far as it is required for the purposes of commerce, by two processes, one of which is called _cupellation_, and the other _parting_. The former of these operations consists in melting the gold with a quantity of lead, which readily oxydizes and vitrifies, and which causes the same changes to take place in the metal to be detached from the mass of gold. The operation is called cupellation, because it is usually performed on a _cupel_, a vessel formed of bone-ashes, or sometimes of wood-ashes. 9. Cupellation is effectual in removing copper, but not so with regard to silver; the latter is separated by means of a process called _parting_. The metal is rolled out into thin sheets or strips, and cut into small pieces. These are put into diluted nitric acid, which, by the aid of a moderate heat, dissolves the silver, leaving the gold in a porous state. 10. Another process, called _cementation_, is also sometimes used. It is performed by beating the alloyed metal into thin plates, and arranging them in alternate layers with a cement containing nitrate of potash, and sulphate of iron. The whole is then exposed to heat, until a great part of the baser metals has been removed by the action of the nitric acid liberated by the nitre. Cementation is often employed by goldsmiths, to refine the surface of articles in which the gold has been combined, in too small a proportion, with metals of less value. 11. The average amount of gold annually obtained in every part of the globe cannot fall far short of twenty-millions of dollars in value, of which South America supplies about one half, and Europe, about one twenty-fifth part. The amount yielded by the Southern states of our Union, cannot be accurately ascertained, but the whole sum coined at the United States' Mint in 1834, from gold obtained in this quarter, amounted to $898,000, and since 1824 to that time, to $3,679,000. In 1824, the sum was but $5000. Our Southern mines will probably continue to increase in productiveness. THE GOLD-BEATER. 1. Gold, not being subject to intrinsic change by atmospheric action, or by that of common chemical agents, is extensively used in gilding various substances, either with the view of preserving them from decay, or for the purpose of embellishment. To prepare the gold for application in this manner is the business of the gold-beater. 2. The metal is first melted with some borax in a crucible, and formed into an _ingot_ by pouring it into an iron mould. The mass is next hammered a little on an anvil, to increase the cohesion of its parts, and afterwards repeatedly passed between steel rollers, until it has become a riband as thin as paper.