172 



It is highly probable, that the great salubrity 

 of the Amazon is owing to this constant breeze. 

 In the stagnant air of the Upper Oroonoko the 

 chemical affinities act more powerfully, and 

 more deleterious miasmata are formed. The in- 

 salubrity of the climate would be the same on 

 the woody banks of the Amazon, if this river, 

 running like the Niger from west to east, did 

 not follow in it's immense length the same di- 

 rection, which is that of the trade-winds. The 

 valley of the Amazon is closed only at it's west- 

 ern extremity, where it draws near the Cordil- 

 leras of the Andes. Toward the east, where 

 the sea breeze strikes the New Continent, the 

 shore is raised but a few feet above the level of 

 the Atlantic. The Upper Oroonoko first runs 

 from east to west*, and then from north to 

 south. Where it's course is nearly parallel to 

 that of the Amazon, a very hilly country, the 

 group of the mountains of Parima and of Dutch 

 and French Guyana, separates it from the At- 

 lantic, and prevents the wind of rotation from 

 reaching Esmeralda. This wind begins to be 

 powerfully felt only from the confluence of the 

 Apure, where the Lower Oroonoko runs from 

 west to east, in a vast plain open toward the 

 Atlantic, and therefore the climate of this part 

 of the river is less noxious than that of the Up- 

 per Oroonoko. 



* Properly from E.S.E., to W.N.W. 



