On adding together the various sums above mentioned, we find that, exclusively of the Russian Empire, which obtains the greater part of its silver (about 65,000 marks a year) from the Altai Mountains in Siberia, the whole annual production of Europe may be estimated at about 400,000 marks. This quantity, large as it is, sinks into comparative insignificance when compared with the enormous masses of silver with which, ever since their discovery and conquest by Cortez and Pizarro, Mexico and Peru have enriched the world. The Mexican silver mines, which deserve a particular notice from the immensity of their produce and the interesting details with which their history abounds, are mostly situated on the back or on the western slopes of the Cordillera of Anahuac at elevations which sometimes approach the line of perpetual snow. But little is known of their first history. The lodes of Tasco and Pachuca appear to have been worked soon after the conquest, and in 1548, twenty-eight years after the death of Montezuma, the mines of Zacatecas were opened, though situated above 400 miles from the capital. Muleteers travelling from Mexico to Zacatecas are said to have discovered the silver mines of Guanaxuato. Many of my readers will no doubt be surprised to hear that the Mexican silver ores are generally poor. On an average they contain only from three to four ounces of silver per cwt., much less than the ores of Annaberg, Marienberg, and other districts of Saxony. Their comparative poverty is, however, amply redeemed by their abundance and the facility with which they are worked. After these preliminary remarks I will now briefly describe the chief Mexican silver mines. The Sierra de Santa Rosa, a group of porphyritic hills, rises in the centre of the province of Guanaxuato. Partly arid and partly covered with the evergreen oak, it attains an absolute height of from 8,000 to 9,000 feet; but, as the neighbouring plain is nearly 6,000 feet above the sea, it hardly attracts the notice of the traveller accustomed to the vast proportions of the Andes.