324 A JOURNEY IN BRAZIL. 



sky. Cool weather here is usually the result of lain. 

 As soon as the sun shows his face the heat is great. But 

 yesterday a strong wind was blowing down the Rio Negro ; 

 and its usually black, still waters were freshened to blue, 

 and their surface broken by white caps. It is a curious 

 fact in the history of this river, that, while tributary to 

 the Amazons, it also receives branches from it. A little 

 above its junction with the Solimoens, the latter sends sev- 

 eral small affluents into the Rio Negro, the entrance to which 

 we passed yesterday. The contrast between their milky- 

 white waters and the clear, dark, amber tint of the main 

 river makes them very conspicuous. It would seem that 

 this is not a solitary instance of river formation in this 

 gigantic fresh-water system ; for Humboldt says, speaking 

 of the double communication between the Cassiquiare and 

 the Rio Negro, and the great number of branches by which 

 the Rio Branco and the Rio HyapuVa enter into the Rio 

 Negro and the Amazons : "At the confluence of the Hya- 

 pura there is a much more extraordinary phenomenon. 

 Before this river joins the Amazons, the latter, which is the 

 principal recipient, sends off three branches, called Uara- 

 napu, Manhama, and Avateparana, to the Hyapura, which 

 is but a tributary stream. The Portuguese astronomer, 

 Ribeiro, has proved this important fact. The Amazons 

 gives waters to the Hyapura itself before it receives that 

 tributary stream. " So does it also to the Rio Negro. 



The physiognomy of the Rio Negro is peculiar, and very 

 different from that of the Amazons or the Solimoens. The 

 shores jut out in frequent promontories, which, while they 

 form deep bays between, narrow the river from distance 

 to distance, and, as we advance towards them, look like 

 the entrances to harbors or lakes. Indeed, we have already 



