the rock. The earth being brought out, and carefully searched, affords stones of various shapes, and of a good water. This earth is of a yellowish, and sometimes of a reddish colour, frequently adhering to the diamond with so strong a crust that the separation becomes difficult.

To find the diamonds, the workmen form a cistern of a kind of clay, with a small vent on one side, a little above the bottom; in this vent they place a plug, and throwing into the cistern the earth they have dug, pour in water to dissolve it. They then break the clods, and stir the wet earth in the cistern, allowing the lighter part to be carried off in the form of mud, when the vent hole is opened to let out the water. They thus continue washing until what remains in the cistern is pretty clean; and then, in the middle of the day, when the sun shines bright, carefully look over all the sand, at which practice they are so expert, that the smallest stone cannot escape them. The brightness of the sun being reflected by the diamonds, aids them in their research, which would be foiled if a cloud were to intervene.

The specific gravity of the diamond is to that of water in the proportion of somewhat more than three and a half to one. It is the hardest of all precious stones, and can only be cut and ground by itself and its own substance. To bring it to the perfection by which its price is so greatly augmented, the lapidary begins by rubbing several of these stones against each other, while rough, having first glued them to the ends of two wooden blocks, thick enough to be held in the hand. The powder thus rubbed off the stones and received in a small box for the purpose, serves to grind and polish them.

The greatest known diamond was found in Brazil, and belongs to the King of Portugal. It weighs 1680 carats ; and, although uncut, is estimated by Rome de l'Isle at the enormous sum of two hundred and twenty-four millions sterling, which gives an estimate of nearly eighty pounds sterling for each carat, the multiplicand of the square of its whole weight being taken. The one next in magnitude and value is that purchased in 1772 by the late Empress of Russia: it weighs seven hundred and seventy-nine carats, and has been estimated at nearly five millions sterling. It ought, however, to be observed, that these estimates, founded on the magnitude and brilliancy of the gems, are

Spaniards endeavour to justify by the plea that labourers could not otherwise be procured. The mita having thus, according to them, been rendered indispensable, they observe that it is conducted with all possible humanity; which those may believe who have never heard of the cruelties they have exercised, it may be said habitually, on the wretched Indians, since the conquest.

Lumps of pure gold and silver, called papas, from their resemblance to the potatoe, are often found in the sands. The poor likewise occupy themselves in lavederos, or in washing the sands of the rivers and rivulets, in order to find particles of the precious metals.

To compensate for the mines which are rendered useless by the irruption of water, or other accidents, rich and new ones are daily discovered. They are all found in the chains of mountains, commonly in dry and barten spots, and sometimes in the sides of the quebredas, or astonishing precipitous breaks in the ridges. However certain this rule may be in the Viceroyalty of Buenos Ayres, it is contradicted in that of Lima, where, at three leagues distance from the Pacific Ocean, not far from Tagna, in the province of Africa, there was discovered not many years ago the famous mine of Huantajaya, in a sandy plain at a distance from the mountains, of such exuberant wealth that the pure metal was cut out with a chisel. From this mine a large specimen of virgin silver is preserved in the royal cabinet of natural history at Madrid. It attracted a con siderable population, although neither water nor the common conveniences for labour could be found on the spot, nor was there any pasturage for the cattle.

In the mint of Potosi about six millions of dollars are annually coined; and the mines of the viceroyalty of La Plata, taken collectively, are reckoned to yield about sixteen millions. The new viceroyalty of Buenos Ayres contains thirty gold mines, twenty-seven silver mines, and sixteen of other metals.

The mines of MEXICO, or NEW SPAIN, have been more celebrated for their riches than those of La Plata, notwithstanding which they are remarkable for the poverty of the mineral they contain. A quintal, or one thousand six hundred ounces of silver ore, affords, at a medium, not more than three or four ounces of pure silver, about one third of