From the opening of the Mexican mines, in the sixteenth century, their production of silver has exceeded that of all other countries. From the annual yield of two or three millions of dollars, it rose, in the eighteenth century, to twenty millions, and continued so for about ten years of the present century, when it was changed by the war of independence. It remained at a low rate until 1850, when it again increased, and in 1856 it was not far from forty millions. Latterly, as already stated, the product has been greatly diminished, and accurate statistics are very difficult to be obtained in regard to it. The total product of the Mexican mines from the time of the conquest by Cortes up to the expulsion of the Spanish in 1827, is said, according to official records, to have been considerably more than two thousand millions of dollars. The silver mines of Northern Mexico, near the boundary of the United States, are supposed to be very rich; but the disturbed state of the country prevented their successful exploitation. Mining operations to some extent have been carried on in some of these districts, and in Arizona, but under many disadvantages. Arizona is a delightful country in every respect, except in climate, soil, production, and inhabitants. The natives have a pleasant way of slaughtering every stranger who attempts to stay there; and sometimes, when they refrain from their amusement for a few months, the strangers fall to killing each other. Until very recently it was said that no white man had ever died in Arizona with his boots off,—meaning that he had never died in bed. The cemeteries at two or three settlements in Arizona are said to contain no graves except those of persons who had died violent deaths at the hands of either white men or Indians. The Indians make travelling very insecure; and the Peons, or native Mexican laborers, in the mines vary the monotony of their employment by an occasional massacre of the superintendent and every other white man about the place. I was at one time acquainted with a superintendent who had twice escaped assassination by reason of accidental absence. He did not take warning by his luck on these occasions, but continued on in his usual way till on the occurrence of another conspiracy he was killed. Closely rivalling the mines of Mexico are those of Peru. They are scattered in various parts of the country, but the richest and most famous are in Potosi, formerly belonging to Peru, but now a part of Bolivia. The story is, that these mines were discovered in 1545, by an Indian hunter, who accidentally exposed lumps of the precious metal in the roots of a bush which he pulled from the ground. His discovery led to careful and extensive explorations, and in a short time the city of Potosi sprung up in a barren and almost inaccessible district.