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geological phenomena. On the east of Javita, 

 all along the Cassiquiare, and particularly in the 

 mountains of Duida, the number of veins in the 

 granite increases. These veins are full of holes 

 and druses, and their frequency seems to indicate, 

 that the granite of these countries is not of very 

 ancient formation. 



We found some lichens on the rock Uinuma- 

 ne, opposite the island of Chamanare, at the 

 edge of the rapids ; and as the Cassiquiare near 

 it's mouth turns abruptly from east to south- 

 west, we saw for the first time this majestic 

 branch of the Oroonoko in all it's breadth. It 

 much resembles the Rio Negro in the general 

 aspect of the landscape. The trees of the forest, 

 as in the basin of the latter river, advance as far 

 as the beach, and there form a thick copse ; but 

 the Cassiquiare has white waters, and more fre- 

 quently changes it's direction. It's breadth near 

 the rapids of Uinumane almost surpasses that 

 of the Rio Negro. I found it every where from 

 two hundred and fifty to two hundred and eighty 

 toises, as far as above Vasiva. Before we pass- 

 ed the island of Garigave, we perceived to the 

 north-east, almost at the horizon, a little hill 

 with a hemispheric summit ; the form which in 

 every zone characterises the mountains of gra- 

 nite. Continually surrounded by vast plains, 

 the solitary rocks and hills excite the attention 

 of the traveller. Contiguous mountains are only 



