The quantity of mineral contained in the rocks of Spain is no less remarkable than the exceptional variety of its distribution; but owing to a series of adverse circumstances, the industrial production affords a most inadequate idea of the capabilities of the mines, if developed by a fair amount of capital and skill. The following figures, showing the production in 1875, are derived from the last official reports issued by the Spanish Government, and are certainly below the truth:-- Tons of ore Tons of metal exported. produced in Spain. Iron 336,000 37,000 Lead 10,000 119,000 Copper 362,000 6,620 Zinc 43,000 3,820 Manganese 14,000 Mercury 1,425 These figures do not include the bar iron produced directly from ore in Spain, nor 160 tons of argentiferous copper ore, 89 tons of cobalt ore, and 440 tons of nickel ore. The silver extracted in Spain amounted to more than 16,000 lbs. troy, while four times that amount was contained in exported argentiferous lead. The coal extracted amounted to 666,000 tons, lignite above 27,000, sulphur above 3000, and phosphorite above 12,000 tons. The year 1875 was, however, peculiarly unfavourable to Spanish mining, and the working of the Bilbao mines, which now produce nearly 2,000,000 tons yearly of excellent iron ore, was then practically suspended by the Carlist war. All disadvantages cannot, however, arrest the steady increase of mineral production in Spain, although under more normal political circumstances the above figures would have been greatly exceeded. The chief coal district is that of Oviedo, Palencia, Leon, and Santander. The coal-field of Oviedo, occupying an extent of 230 square miles, and including a large number of workable beds, is of excellent quality, but as yet little developed, owing to high railway tariffs, bad condition of ports, traditional prejudices, want of skill and capital, and of a local market for inferior qualities. These obstacles will probably soon be overcome, and the development of the associated iron ores afford an important field of enterprise.