In order to bring together whatever may enlighten the government of this country on a subject so long disputed, I will enter upon a few more geological considerations. The mountains of Brazil, notwithstanding the numerous traces of embedded ore which they display between Saint Paul and Villa Rica, have furnished only stream-works of gold. More than six-sevenths of the seventy-eight thousand marks (52,000 pounds) of this metal, with which at the beginning of the 19th century America annually supplied the commerce of Europe, have come, not from the lofty Cordilleras of the Andes, but from the alluvial lands on the east and west of the Cordilleras. These lands are raised but little above the level of the sea, like those of Sonora in Mexico, and of Choco and Barbacoas in New Granada; or they stretch along in table-lands, as in the interior of Brazil.* (* The height of Villa Rica is six hundred and thirty toises; but the great table-land of the Capitania de Minas Geraes is only three hundred toises in height. See the profile which Colonel d'Eschwege has published at Weimar, with an indication of the rocks, in imitation of my profile of the Mexican table-land.) Is it not probable that some other depositions of auriferous earth extend toward the northern hemisphere, as far as the banks of the Upper Orinoco and the Rio Negro, two rivers which form but one basin with that of the Amazon? I observed, when speaking of El Dorado de Canelas, the Omaguas and the Iquiare, that almost all the rivers which flow from the west wash down gold in abundance, and very far from the Cordilleras. From Loxa to Popayan these Cordilleras are composed alternately of trachytes and primitive rocks. The plains of Ramora, of Logrono, and of Macas (Sevilla del Oro), the great Rio Napo with its tributary streams* (the Ansupi and the Coca, in the province of Quixos (* The little rivers Cosanga, Quixos, and Papallacta or Maspa, which form the Coca, rise on the eastern slope of the Nevado de Antisana. The Rio Ansupi brings down the largest grains of gold: it flows into the Napo, south of the Archidona, above the mouth of the Misagualli. Between the Misagualli and the Rio Coca, in the province of Avila, five other northern tributary streams of the Napo (the Siguna, Munino, Suno, Guataracu, and Pucono) are known as being singularly auriferous. These local details are taken from several manuscript reports of the Governor of Quixos, from which I traced the map of the countries east of the Antisana.)), the Caqueta de Mocoa as far as the mouth of the Fragua, in fine, all the country comprised between Jaen de Bracamoros and the Guaviare,* (* From Rio Santiago, a tributary stream of the Upper Maranon, to the Llanos of Caguan and of San Juan.) preserve their ancient celebrity for metallic wealth. More to the east, between the sources of the Guainia (Rio Negro), the Uaupes, the Iquiare, and the Yurubesh, we find a soil incontestably auriferous.