Many of these deposits are remarkable for the richness of their ores, and for the large masses of native or crystallised silver which they have sometimes yielded. From the mine of Himmelsfürst, near Freiberg in Saxony, lumps or nuggets weighing above a hundred pounds have more than once been extracted. The largest single block ever known was discovered at Schneeberg, in the Saxon Erzgebirge, in the year 1477. It consisted of silver-glance and native silver, and measured no less than seven yards in length and three and a half in width. On hearing of this magnificent prize, Duke Albrecht of Saxony visited the mine, where he eat his dinner from the block. Agricola Bermannus relates that, during the repast, he exclaimed, ‘Frederick is a wealthy and powerful emperor, but he has never dined from a table such as this.’ The subsequent smelting of this wonderful mass produced 40,000 pounds of solid silver. Large nuggets of solid silver have likewise been found at Kongsberg. A block weighing 560 pounds, which was discovered in 1666, is still preserved as a curiosity in the Copenhagen Museum; and as a convincing proof that the ancient riches of these northern mines are not yet exhausted, a still larger block, weighing 750 pounds, was disinterred as late as the year 1834. Though native silver is found in many localities, our chief supply of the precious metal is derived from the ores in which it is found combined with other substances, such as silver-glance (sulphuret of silver); antimonial silver; red-silver (sulphuret of silver and antimony); horn silver (chloride of silver), &c. A considerable quantity is likewise obtained as an accessory product from the lead mines, by separating it from the galena or lead-glance, which usually contains a small percentage of silver. At present the mines of the Austro-Hungarian Empire, which in the year 1851 produced 122,950 marks of silver, are the richest in Europe. In Bohemia the mines of Birkenberg, near Przibram, yield on an average 40,000 marks a year, considerably more than the celebrated mine of Schemnitz in Hungary, which in the year 1854 produced 26,064 marks. Prussia obtains from her mines in the Hartz Mountains in Nassau and the county of Mansfeld about 100,000 marks; and the kingdom of Saxony, which, in proportion to its small extent, holds the first rank among the silver-producing countries of Europe, produces annually about 53,000 marks. In Great Britain, silver is accessorily obtained from the lead mines, to an amount of about 80,000 marks per annum. France produces 26,800 marks, Sweden and Norway 6,000 marks, and Italy 4,500; while Spain, which in ancient times enriched Tyre and Carthage with the rich produce of her silver mines, yields at present but an insignificant quantity.