TITE QBANITES OF GUIANA. 65 



trade with more southern nations; but nothing indicates 

 that they ever constructed an edifice of stone. We saw no 

 vestige of any during the course of our journey. 



Though the celebrity of the riches of Spanish Guiana is 

 chiefly assignable to the geographical situation of the coun- 

 try, and the errors of the old maps, we are not justified in 

 denying the existence of any auriferous land in the tract 

 of country of eighty-two thousand square leagues, which 

 stretches between the Orinoco and the Amazon, on the east 

 of the Andes oi Quito and New Granada. What I saw of 

 this country between the second and eighth degrees of lati- 

 tude, and the sixty-sixth and seventy-first degrees of longi- 

 tude, is entirely composed of granite, and ot a gneiss passing 

 into micaceous and talcous slate. These rocks appear naked 

 in the lofty mountains of Parima, as well as in the plains 

 of the Atabapo and the Cassiquiare. Granite predominates 

 there over the other rocks; and though, in both continents, 

 the granite of ancient formation is pretty generally destitute 

 of gold-ore, we cannot thence conclude that the granite of 

 Parima contains no vein, no stratum of auriferous quartz. 

 On the east of the Cassiquiare, towards the sources of the 

 Orinoco, we observed that the number of these strata and 

 these veins increased. The granite of these countries, by its 

 structure, its mixture of hornblende, and other geological 

 features alike important, appears to me to belong to a more 

 recent formation, perhaps posterior to the gneiss, and analo- 

 gous to the stanniferous granites, the hyalomictes, and the 

 pegmatites. Now the least ancient granites are also the 

 least destitute of metals ; and several auriferous rivers and 

 torrents in the Andes, in the Salzburg, Fichtelgebirge, and 

 the table-land of the two Castiles, lead us to believe that 



granites sometimes contain native gold, and portions of 

 auriferous pyrites and galena disseminated throughout the 

 whole rock, as is the case with tin and mngnetic and mica- 

 ceous iron. The group of the mountains ol Parima, several 

 summits of which attain the height of one thousand three 

 hundred toises, was almost entirely unknown before our visit 

 to the Orinoco. This group, however, is a hundred leagues 

 lon,', and eighty broad ; ana though wherever M. Bonpland 

 and I traversed this vast group of mountains, its structure 



d to us extremely uniform, it would bo wrong to affirm 



VOL. III. f 



