192 



rivers, the-Machangara, the Rio del Matadero, 

 and the Yanuncai ; of which the two former are 

 white, and the waters of the last are black 

 (aguas negras). These waters, like those of 

 the Atabapo, are of a coffee colour by reflec- 

 tion, and pale yellow by transmission. They are 

 very fine, and the inhabitants of Cuenca, who 

 drink them in preference, do not fail to attribute 

 their colour to the sarsaparilla, which it is said 

 grows abundantly on the banks of the Rio Ya- 

 nuncai*. 



April 23d. We left the month of the Zama 

 at five in the morning. The river continued 

 to be skirted on both sides by a thick forest. 

 The mountains on the east seemed to retire by 

 degrees farther back. We passed first the 

 mouth of the Rio Mataveni, and afterward an 

 islet of a very singular form ; a square granitic 

 rock, that rises like a trunk in the middle of 

 the water. It is called by the missionaries 

 El Castiliito. Black bands seem to indicate, 

 that the highest swellings of the Oroonoko do 

 not rise at this place above eight feet ; and 

 that the great swellings observed lower down 

 are owing to the tributary streams, which 



* Although the species of smilax abound principally in hot 

 and temperate regions (from 0 to 500 toises) , we have how- 

 ever found them between 700 and 1400 toises. See our 

 Nov, Gen. Plant., vol. 1, p, 72. 



