The Aborigines of Brazil. 171 



zil in this point of view, we may recognize in this vast coun- 

 try a triple character as to disease. 



1. The immense basin of the Amazon with its northern 

 and southern tributaries. This river valley, the largest on 

 the surface of the earth, following the equator in its chief di- 

 rection from west to east, and also in that of its most impor- 

 tant tributary the Madeira, from the 19° of South latitude 

 to the equator, partaking every where of a true equatorial cli- 

 mate, is a low damp land. The overflowing of the rivers, 

 and of the endless lakes and ponds in connexion with them, 

 endure on the average for two-thirds of the year. There 

 is no dry season here as in the other divisions ; thick 

 forests, always green, and incessantly attracting damp clouds, 

 alternate with plains only, in the higher lying districts. 

 Throughout the whole year day and night vary little in 

 length ; cold winds never prevail. In the later months of the 

 year there blows in the chief basin of the Amazon, the 

 wind called the general, an East wind, which is general- 

 ly without any unfavourable influence on the constitution, 

 since it cools, without making people catch cold, and common- 

 ly diminishes the plague of musquitoes. Universal nature is 

 here subject to that peculiar rest, that regularity in all the phse- 

 nomena of terrestrial life, and to that beautiful harmony of the 

 elements, which makes equatorial regions so attractive. The 

 prevalent diseases correspond with these relations ; feverish 

 exanthemata, dysenteries, dropsies, obstruction of the liver, 

 and of the portal circulation, and chronic inflammation of 

 the liver prevail. All inflammations shew a venous or pas- 

 sive character ; they are less strongly marked than in more 

 southern climates ; great failure of strength,- and rapidly 

 supervening colliquation render diarrhoeas and dysenteries, 

 which are often caused by catching cold, and by eating un- 

 ripe fruits, especially dangerous. The infectious exanthe- 

 mata spread with unusual violence. Dropsy in its various 



