CATARACTS OF THE ORINOCO. 175 



origin of the Orinoco. The doubts raised by an eminent geographer, 

 M. Buache, since 1797, as to the probability of a connection with 

 the Amazons, have, I hope, been entirely refuted by my expedition. 

 In an uninterrupted navigation of 920 geographical miles, I passed 

 through the singular network of rivers, from the Rio Negro, by the 

 Cassiquiare, into the Orinoco ; traversing in this manner the interior 

 of the Continent, from the Brazilian boundary to the coast of Ca- 

 raccas. 



In the upper portion of the basin of the Orinoco and its tributaries, 

 between the 3d and 4th degrees of north latitude, nature has several 

 times repeated the enigmatical phenomenon of the so-called " black 

 waters." The Atabapo, whose banks are adorned with Carolinias 

 and arborescent Melastomas, and the Temi, Tuamini, and Guainia, 

 are all rivers of a coffee-brown color. In the shade of the palm 

 groves this color seems almost to pass into ink-black. When placed 

 in transparent vessels, the water appears of a. golden yellow. The 

 image of the Southern Constellations is reflected with wonderful 

 clearness in these black streams. Where the waters flow gently, 

 they afford to the observer, when taking astronomical observations 

 with reflecting instruments, a most excellent artificial horizon. A 

 cooler atmosphere, less torment from stinging mosquitoes, greater 

 salubrity, and the absence of crocodiles (fish, however, are also want- 

 ing), mark the region of these black rivers. They probably owe 

 their peculiar color to a solution of carburetted hydrogen, to the 

 luxuriance of the tropical vegetation, and to the quantity of plants 

 and herbs on the ground over which they flow. On the western de- 

 clivity of the Chimborazo, towards the coast of the Pacific, I re- 

 marked that the flooded waters of the Rio de Guayaquil gradually 

 assumed a golden yellow or almost coffee-brown color, when covering 

 the meadows for some weeks. 



In the vicinity of the mouths of the Gruaviare and Atabapo grows 

 the Piriguao ( 10 ), one of the noblest of palm trees, whose smooth 

 and polished trunk, between 60 and 70 feet high, is adorned with a 

 delicate flag-like foliage curled at the margins. I know no palm 

 which bears such large and beautifully colored fruits. They resemble 

 peaches, and are tinged with yellow mingled with a roseate crimson. 

 Seventy or eighty of them form enormous pendulous bunches, of 



