The minerals of Potosi are consequently extreme ly_ poor, and it is owing to their abundance alone, that they still produce so great a quantity of silver. From 1574 to 1789, the mean quantity .of silver af forded by the ores has dituinished in the proportion of 170 to one, while the silver extracted from the mines has only diminished in the proportion of fonr to one. It thus appears that the ,productiveness of mines does not by any means depend so much on the richness or Ftoverty of•the minerals which they contain, as on their abundance, and the facility •with which they are worked. It •tuappens, ac -cordingly, that the Mexican mines, which are -the ih the world, contain remarkably poor -minerals, the best yielding, on an average, from to 5•A- ; the middling from to and the worst about ounces of silver for every 1600 ounces of ore. In some of the mines of Germany, on the other hand, of which the produce falls so far short of those of South America, the mean propor tion of silver is found to amount to 10 ounces per -quintal, and in fortUnate periods to 15. • From 1545 till 1 571 , the silver minerals of Potosi (were all smelted in portable furnaces contrived by -the Indians. These were cylindrical tubes of clay, 'very broad, and pierced with a number of holes, which, admitting the air, gave the flame a great de gree of intensity. About the year 1571, the method of amalgamation with mercury was introduced ; and of the 8000 or 10,000 quintals produced by the mine of Guancunelica towards the end of the six teenth century, above 6000 or 7000 quintals were consumed in the works of Potosi. About the year 1763, the consumption amounted to between 1'6,000 and 17,000 quintals annually. There are at present 2000 miners engaged in the works at Potosi, who are paid at the rate of 255. per day. Fifteen iljuu. sand lamas, and an equal number of asses, are em ployed in carrying the ore from the mountain of Po tosi to the amalgamation works.
Gold is found in most of the mountainous districts •of this viceroyalty. It is either worked in mines, gathered from the sands, • or collected from the streams. Near the town of Mojos, there is a consi derable stratum of rich magnetical iron sand, in which are found particles of gold of the use of a lentil, and sometimes as heavy as the quarter of a ducat. The Indians, however, by their unskilful mode of working the sand, lose all the finer particles of the gold, which carried away by the stream. From the town of Mojos to within a short distance of Potosi, from which it is distant 180 miles, similar alluvial layers occur, and gold is washed from them, especially at the little town of *Jag° de Cotagoita, which is distant about 90 miles from Potosi. In the province of Lipes there are gold mines, many of which have been abandoned. But two are now work. ed, and one of copper, the strata of which are inter mixed with gold, silver, iron, and leadstone. In•Puno and Oruro, there are several gold mines. But most of them have gone to decay from the inactivi. ty of the inhabitants, or they have been overflowed, and all efforts to drain them have been found una vailing. The most abundant mines are in the ire wince of Cochabamba and Sicasica. The whole of the mountains in this last district, where the Indian collect ore by working, abound in rich gold ore, and when, about a hundred years ago, a projecting part fell- down, lumps of puce gold, weighing from two to fifty pounds, were seVered from the stone; 'and, even in the present times, in the layers of sand washed from the mountain by the rain water, piece of pure gold are found, Mane of which weigh a ounce. From the ignorance of the inhabitants, how
ever, most of these treasures lie totally neglected.
A very brief and general account of the animal of this country, is all that can be attempted within oe present limits. The horses and horned cattle, origi nally imported from Europe, have multiplied sins ingly In the extensive plains of South ..kinerics. Asses, mules, European sheep, stags of different spe• cies, foxes, ;abbits, goats, and- hogs, are numerous, and great numbers of wild dogs are to be met with. These are descended from those of a domestic kind that have left their masters in pursuit of the game, with which the country everywhere abounds. The other wild animals are the puma or American lion, the jaguar and cougar, two species of American gers, which are strong and ferocious animals, and commit great devastations among' the flocks. The jaguar, when full grown, is a large animal, some of them measuring five feet from the nose to the root of the tail, which is two additional feet long, and so strong that they will drag the carcase of a horse or ball which they have killed to the place where they intend to devour it. They are excellent swimmers, and Amara mentions, that he has seen them swim ming across a large river loaded with their prey. The Puma is a weak and cowardly animal, and is now become very scarce in the parts inhabited by the Spaniards. The guazuara, called the cougar by Buffon, is 47 inches long, without including the which is 26 inches long. It flies from the human species, but kills calves, sheep, pigeons, and all other smaller animals. It does not stop to eat the flesh, but is contented with licking the -blood. Of the other animals, the most remarkable are the ants or dente, which is between the elk and buffalo species. It is of the size of a large ass, has 110 horns, and is of singular strength. It is frequent ly found in the forests and plains of Paraguay, but has been so much hunted both for its skin and flesh, that it is scarce both in Tucuman and Buenos Ayres.' The armadillos are very numerous all over South America, and are of various species, differing in size, and in the nature of the armature with which they are covered. The tamandua, or nurumi, or ant-eater, is 53* inches long, without reckoning the tail, which is• in length 22* inches, besides a thick, bunch of hair at its end, 11 inches long. A sera enumerates various other small animals, which are generally car ' nivorous, preying upon birds, reptiles, or other, infe rior quadrupeds. The chibi-guazu, which he consi ders to be the jaguar of New Spain, or the tiger cat of other countries, is 84 inches, and the tail IS inches. Wild cats are found of various sorts. There are also several animals which have the form of the martin, the pole-cat, and the ferret, but which are much larger and' stronger. The sarigue or the fe cundo, is a small animal peculiar to America, which • preys upon pigeons, mice, insects, eggs, &c. It has a long triangular and pointed face ; its eyes are oblique and jutting out. Its mouth is large, and well furnished with teeth. Its tail is long, thick, and Covered with scales, which it uses to climb up trees and walls when the surfice is in any degree rough. It has long whiskers, and its ears are round, naked, and transparent.