At the mouth of the great mine, called the King’s mine,—“La mina del Rey,”—which rendered the family of Yjura so famous and so wealthy,—a labourer has been known in our own day to refuse eighty dollars for his mantada, which abounded in pieces of polvorilla and maciza, or ore rich in native and nearly pure silver. Native and massive silver is, however, necessarily rare, and only occurs in small and scattered portions among other metals of good quality. The better the quality of the ore, so much greater is the damage and loss from robbery sustained by the mine and master miner; and it often happens that the cost of raising the ore, extracting the silver, paying government and local duties, the repair of the underground works, supply of salt and quicksilver, together with all the expense of major-domos, and wear and tear of mining utensils, loss on cargo-mules and llamas, &c. exceed the whole returns of the mine. Hence, we have known a most intelligent, active, and distinguished master miner of Pasco, four or five of whose mines yielded mostly all the rich ore extracted from that mineral in the years 1827 and 1828, declare that, after having put about two millions of dollars in circulation from the produce of these mines, he himself was rather a loser than a gainer, notwithstanding such abundant returns. The number of mines at Cerro usually at work since they have fallen into the hands of the Patriots are comparatively few: though in the different districts or sections of this place, known under the names Santa Rosa, Yauricocha, Caya, Yanacancha, Cheupimarca, and Matagente, there are several hundred well-known mines from which silver has been, and yet may be, plentifully dug out, provided a perfect drainage should ever be effected. The mines of late actually productive in Cerro Pasco may be said generally to amount to about thirty in number, and to be at work for about eight months in the year. Some of these are of course of inferior quality; but the metals which, by assay or experiment on the small scale, only yield six or seven _marcs_ per _cajon_ or box, (the marc being eight ounces, and the cajon twenty-five mules’ load of ten arrobes, or two hundred and fifty pounds each,) are found to be worth the working, provided the ore be not very difficult to extract, either on account of the character of the vein, or the depth of the workings. The metals of Santa Rosa, when they yield ten marcs of silver per cajon, and when quicksilver is at a moderate price, pay the miner better than richer ores, because they do not tempt the cupidity of the labourers, who are therefore contented with the fixed sum of four reals wages per day, instead of the mantadas or bundles of metal already mentioned.