of the metals in comparison with other products, caused mines which had before been successfully worked to be abandoned as unprofitable. From 1492 to 1500 the annual amount of gold brought into Europe from America is rated by Humboldt at £52,000; till 1519 gold only was obtained. The same proportion may savely be extended to the year 1521, when Mexico was conquered, and the precious metals, but more especially silver, were obtained in vastly larger quantities. The mines of Potosi, discovered in 1546, gave a still greater preponderance to the production of silver, and no data are afforded for afterward distinguishing the relative proportions of the two metals. But in the first 300 years succeeding the discovery, the receipts of American gold were estimated at 3½ times the product of the mines of the old continent, and those of silver at 12 times the product of this metal. In the time of Elizabeth gold was obtained at Leadhills in the south of Scotland; and toward the close of the last century, in the county of Wicklow in Ireland, about $50,000 worth of gold was collected in two months. These deposits soon, however, proved unprofitable. The metal was in ancient times collected in Cornwall, and is known to exist in Devonshire. The largest portion of British gold has been the product of Wales, the principal gold-bearing district of which is confined to an area of about 25 sq. m. in North Wales. The mines are still worked, but there has been a great decrease in the production. Upon various rivers of Europe, as the Rhine, the Rhône, the Danube, the Reuss, and the Aar of Switzerland, the sands were known to be auriferous in places, but too poor to pay the expenses of working. In Hungary veins containing gold disseminated in ores of sulphuret of silver are worked in a partially decomposed feldspar of the trachytic formation, and also in syenite and porphyritic greenstone; and gold is also extracted from auriferous pyrites of trap rocks of the most recent formation. The mines of Nagy-Ág and Zalatna in S. W. Transylvania produce the alloy of tellurium and gold before referred to. Besides gold, the Hungarian mines, worked by the Austrian government, produce copper, silver, mercury, antimony, lead, iron, and cobalt. In the Austrian provinces of Salzburg and Tyrol, at Bockstein and at Zell, gold is extracted from poorer ores than are elsewhere ever found profitable to work. The quartz gangue of the veins and the argillaceous slates of the walls contain auriferous pyrites, argentiferous mispickel, gray argentiferous copper, and sulphuret of silver. From these the gold is profitably extracted when it amounts to only from 6 to 15 parts in 1,000,000. At Zell it has been stated that the annual product of 50,000 quintals of ore has been only 35 marks of gold, or 4 parts in 1,000,000. The silver, though obtained in six or seven times the quantity of the gold, is still less than half its value. The total production of the Austrian mines for several years past has averaged from 5,500 to 5,800 oz. per annum. In Italy various localities were known to the ancients as producing gold. At present the only mines of consequence are in Piedmont, in the valleys of Anzasca, Toppa, and Antrona, and to a less extent in those of Alagna, Sesia, and Novara. In Lombardy the chief mines are at Peschiera and Minerva di Sotto. The ore is an auriferous pyrites containing about 12 dwts. of gold per ton. The total yield of all the mines does not exceed $100,000 per annum. In France a small amount of gold is produced, chiefly from auriferous galena; and there are deposits in Savoy. Gold mines have been worked in Spain from very remote periods, but the present annual production does not exceed about $10,000. The mines of the Asiatic slopes of the Ural extend along the secondary ridges of the chain in a N. and S. direction more than 400 m. The crystalline rocks here contain veins, one of which is successfully worked at Berezov, near Yekaterinburg, by shafts and levels. The gangue is pyritiferous quartz with oxide of iron resulting from its decomposition, and the rock is a partially decayed granite, the quartz remaining in angular grains; the adjoining formations are talcose and chloritic slates. All the other workings of Russia are alluvial mines. These are not only in the Ural district, where they have been worked for more than a century, but during the reign of Nicholas a region of southern and eastern Siberia, estimated to be as large as all of France, was found to be more rich in gold than that of the Ural. From the great E. and W. chain of the Altai mountains, which lie between Siberia and Mongolia, low ridges are directed toward the north into the governments of Tomsk and Yeniseisk, and these ridges of crystalline rocks are the repositories of the precious metals. In 1843 this region produced the value of about $11,000,000, while the product of the Ural districts for the same year was only about $2,500,000. Until the discovery of the mines of California it made Russia the greatest gold-producing country of the world. The average production of the Russian mines amounts to about $15,000,000 annually; and their total production from their discovery about 1745 to 1874 may be stated in round numbers at $600,000,000. The product in 1865 was given by Phillips at 69,500 lbs. troy.—Little is known of the other gold regions of the continent of Asia. The metal is possessed, and its deposits are no doubt worked to considerable extent, by all the principal nations; but except from the islands of the Indian archipelago little of it falls into the general circulation of the world. The river Pactolus of Asia Minor is supposed to have furnished from its golden sands the foundation of the wealth of Crœsus. According to Pumpelly, who made geological researches in China, Mongolia, and Japan during 1862-'5, gold exists in numerous localities in no fewer than 14 of the 19 provinces of China. The richest regions appear
