The Jujuy river rises near the Abra de Cortaderas, about three leagues from Colorados, one of the most elevated points passed by the traveller on the road to Potosi: from thence the lofty peak of Chorolque beyond Tupiza, in the north, and the snowy ranges of Atacama, in the north-west, are distinctly visible. The channel of the river in its descent from this elevated region, the whole way to Jujuy, is little more than a succession of precipitous ravines, occasionally swelling into basins, highly interesting to the geologist, as exhibiting on all sides evidences of the tremendous convulsions which at some remote period must have torn and shaken this part of the continent to its very foundations. The road to Potosi winds along it, but it would seem to be a region only suited to the wild llamas, alpacas, and vicuñas, which range in countless herds over the snowy ranges above, looking down with apparent surprise on the casual traveller, who wends his toilsome way through these rugged defiles. The favourite food of these animals is the ichú, a very coarse grass, which is only found at an elevation little short of that of perpetual snow. At Jujuy the river turns eastward through a more open and habitable region, which skirts the southern base of these mountain ranges, and about twenty leagues beyond receives the Siancas, or Lavayen, its most important tributary, which rises in the heights of San Lorenzo, to the north-west of the town of Salta:--it is afterwards joined by the Ledesma and three or four other minor streams, before it falls into the Tarija river, as before stated, below Oran. The course of the Tarija, in the first instance, is nearly as precipitous as that of the Jujuy, running through broken mountainous passes; but when it trends to the south, and receives the Pescado (which separates the departments of Oran and Tarija), and shortly after the Senta, it opens into wide and extensive valleys, traversed by many streams, which, running down into the main river, irrigate the rich lands along its shores, and unite with the warmth of a tropical climate to form one of the most fertile districts in the world. These are the principal rivers of this province. Its productions are as various as its physical features. In the west the mines of the Cerro de Acay and San Antonio de los Cobres, have been at times worked with considerable success; and in the still more elevated districts bordering upon Atacama, the natives of Cochinoca, the Rinconada, Cerillos, Santa Catalina, and Rosario, employ themselves in collecting considerable quantities of gold from the alluvial deposits after heavy rains. It is in those cold regions that the alpacas and vicuñas are found:--the guanaco also abounds there, and the beautiful little chinchilla, thousands of dozens of the skins of which are yearly collected and sent down to Buenos Ayres for exportation to Europe.