The revenues of the caliphs of Cordova are represented to have amounted annually to twelve millions and forty-five thousand dinars of gold.[15] Independent of this income in money, many imposts were paid in the products of the soil; and among an industrious agricultural {71} population, possessed of the most fertile country in the world, this rural wealth was incalculable. The gold and silver mines, known in Spain from the earliest times, were another source of wealth. Commerce, too, enriched alike the sovereign and the people. The commerce of the Moors was carried on in many articles: silks, oils, sugar, cochineal, iron, wool (which was at that time extremely valuable), ambergris, yellow amber, loadstone, antimony, isinglass, rock-crystal, sulphur, saffron, ginger, the product of the coral-beds on the coast of Andalusia, of the pearl fisheries on that of Catalonia, and rubies, of which they had discovered two localities, one at Malaga and another at Beja. These valuable articles were, either before or after being wrought, transported to Egypt or other parts of Africa, and to the East. The emperors of Constantinople, always allied from necessity to the caliphs of Cordova, favoured these commercial enterprises, and, by their countenance, assisted in enlarging, to a vast extent, the field of their operations; while the neighbourhood of Africa, Italy, and France contributed also to their prosperity. The arts, which are the children of commerce, and support the existence of their parent, added {72} a new splendour to the brilliant reign of Abderamus. The superb palaces he erected, the delicious gardens he created, and the magnificent fetes he instituted, drew to his court from all parts architects and artists of every description. Cordova was the home of industry and the asylum of the sciences. Celebrated schools of geometry, astronomy, chymistry, and medicine were established there--schools which, a century afterward, produced such men as Averroes and Abenzoar. So distinguished were the learned Moorish poets, philosophers, and physicians, that Alphonso the Great, king of Asturia, wishing to confide the care of his son Ordogno to teachers capable of conducting the education of a prince, appointed him two Arabian preceptors, notwithstanding the difference of religious faith, and the hatred entertained by the Christians towards the Mussulmans. And one of the successors of Alphonso, Sancho the Great, king of Leon, being attacked by a disease which it was supposed would prove fatal in its effects, went unhesitatingly to Cordova, claimed the hospitality of his national enemy, and placed himself under the care of the Mohammedan physicians, who eventually succeeded in curing the malady of the Christian king. {73} This singular fact does as much honour to the skill of the learned Saracens as to the magnanimity of the caliph and the trusting confidence of Sancho.