AURIFEROUS SOILS. 67 



Rica, have furnished only stream-works of gold. More than 

 six-sevenths of the seventy-eight thousand marks (52,0007.) 

 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.* 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 iii 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 Bio 

 Napo with its tributary streamsf (the Ansupi and the Coca, 

 in the province of Quixos), 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,J preserve 

 their ancient celebrity for metallic wealth. More to the 

 east, between the sources of the Guainia (Rio Negro), the 

 TJaupes, the Iquiare, and the Yurubesh, we find a soil in- 



* The height of Villa Rica is six hundred and thirty toises ; but the 

 great table-land of the Capitania de Miflas Geraes is only three hundred 

 toises in height. See the profile which Colonel d'Eschwege has published 

 at \Veimar, with an indication of the rocks, in imitation of my profile of 

 the Mexican table-land. 



f The little rivers Cosanga, Quixos, and Papallacta or Maspa, which 

 form the Coca, rise on the eastern slope of the Nevada 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. Be- 

 tween the Misagualli and the Rio Coca, in the province of Avilu, five other 

 northern tributary streams of the Napo (the Siguna, Munino, Suno, Gua- 

 taracu, 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. 



t From Rio Santiago, a tributary stream of the Upper Marafion, to 

 the Llanos of Caguan and of San Juan. 



r 2 



