472 



Guyana in America, and Dar-Saley, or Bagher- 

 mi*, in Africa, suggest to us how much the 

 communications by natural channels may have 

 been heretofore more frequent than at present-^. 



After having considered the bifurcation of 

 the Oroonoko in relation to comparative hydro- 

 graphy, it remains for me to relate succinctly 

 the history of the discovery of this extraordinary 

 phenomenon. The same thing has happened 

 with respect to the communication of two great 

 systems of rivers, as to the course of the Niger 

 toward the east. It required, that a discovery 

 should be repeatedly made, which appeared at 

 first contrary to analogy and received hypothe- 

 ses. When travellers had recognized the mode 

 of communication between the Oroonoko and 

 the Amazon, the possibility of the fact was still 

 repeatedly called in question. A chain of moun- 

 tains, which the geographer Hondius had ima- 

 gined, at the end of the sixteenth century, in 

 order to separate the basins of the rivers, was in 



• To the south-east of Bornou and the Lake Nou, in that 

 part of Soudan, where, according to the latest ideas acquired 

 by my unfortunate friend, Mr. Ritchie, the Niger receives 

 the Shary, and falls into the White Nile. 



t On the communications that still exist temporarily, at 

 the time of great rains, between the basin of the river St. 

 Lawrence and that of the Mississippi, see chap, xvi, vol. iv, 

 p. 151 ; and on the inundation of a raviri, by means of which 

 a monk of Choco has joined the South Sea to the Atlantic 

 Ocean, see my Political Essay, vol. 1, p. 25. : 



