217 



the Rio Negro, the Uaupes and the Iquiare; 

 the other, between the sources of the Essequebo, 

 the Caroni, and the Rupunuri. I flatter myself 

 that if the government of Venezuela should 

 ever make a thorough examination of the prin- 

 cipal metallic beds of its soil, the persons to 

 whom those researches are confided, will find 

 in the 13th, 16th, 17th, 24th, and 27th chapters 

 of this work, geognostic notions which may be 

 useful to them, because they are founded on a 

 detailed knowledge of the localites *. Hitherto 

 only one working is found in Venezuela, that of 

 Aroa ; it furnished, in 1800, near 1500 quintals 

 of copper of an excellent quality. The green- 

 stone rocks of the passage mountains ofTucu- 

 tunemo (between Villa de Cura and Parapara) 

 contain veins of malachite and copper pyrites. 

 The indications of both ocherous and magnetic 

 iron in the coast chain, the native alum of Chu- 

 paripari, the salt of Araya, the kaolin of Silla, 

 the jade of the Upper Oroonoko, the petrolium 

 of Buen-Pastor, and the sulphur of the eastern 

 part of New Andalusia, equally merit the atten- 

 tion of the administration -f-. 



It is easy to ascertain the existence of some 

 mineral substances, which afford hopes of a lu- 



* Vol. iii, p. 524—535 ; Vol. iv, 252, 269, 274, 470 ; 

 Vol.v, 311, 342, 401, 507, 559, 809, 826, 852, 863. 



f Vol. ii,p. 254—272 j Vol. iii, p. 103—108, 204. Vol. iv, 

 p. 51 ; and in the present volume, p. 103. 



