172 The Aborigines of Brazil. 



forms, is the disease of which most Indians die ; worm di- 

 seases in various complications are very frequent. 



2. The physical conformation of the northern provinces, 

 Ciara, Rio Grande and Paraiba do Norte, Alagoas, Pernam- 

 buco and Bahia is quite different. This large tract of coun- 

 try is perhaps the most healthy of all, but it is at pre- 

 sent only inhabited along the coast by a few Indians, 

 chiefly civilized offshoots of the Tupi race, and in the 

 interior by a few small groups of tribes that have settled 

 in it ; it is a hot dry land, with less vegetation. The rainy 

 season, which in the basin of the Amazon may be said to 

 extend over the whole year, has its duration contracted 

 here. It is often entirely absent for several years. The rivers, 

 as compared with those of other districts, are poor streams. 

 Their inundations are trifling, and have no such important 

 effect on the vegetation and the general phenomena de- 

 pending thereon. The land rises into hills or elevated 

 table lands. It is much more exposed to the winds than the 

 equatorial districts, and when they come from the sea coast, 

 they often produce fever and diarrhoeas ; when they blow from 

 the west or north-west, rheumatic and catarrhal affections 

 and inflammations, especially of the eyes. The steady clear- 

 ness and warmth of the atmosphere braces the nervous 

 system. The dryness prevents the tendency to colliqua- 

 tion and putrid fever. This very favourable constitution of 

 land and climate prevails almost every where. Only some 

 of the larger rivers, especially the chief streams of the 

 district, the Rio de S. Francisco and the Parnahyba, form an 

 exception. In the neighbourhood of those rivers, and as 

 far as the inundations and the pestilent effluvia connected 

 with them reach, the chronic inflammations of the liver which 

 have been already described prevail under the form of pu- 

 trid and bilious fevers. They commence at the end of the 

 inundations, and decimate the population in a fearful way, 



