406 
PHYSICAL GEOGRAPHY OP 
its length, following the main curves, but disregarding 
the minuter windings, is 2740 English miles. 
Its extent, in a straight line from east to west, is about 
2050 miles ; and from north to south, its tributary 
streams cover a space of 1720 miles. 
The whole area of its basin, not including that of the 
Tocantins, which I consider a distinct river, is 2,330,000 
English square miles, or 1,760,000 nautical square miles. 
This is more than a third of all South America, and 
equal to two- thirds of all Europe, All western Europe 
could be placed in it without touching its boundaries, 
and it would even contain our whole Indian empire. 
The numerous tributary streams of the Amazon, 
many of them equal to the largest rivers of Europe, 
differ remarkably in the colour of their waters, the cha- 
racter of the vegetation on their banks, and the animals 
that inhabit them. They may be divided into three 
groups, — the white-water rivers, the blue-water rivers, 
and the black -water rivers. 
The main stream of the Amazon itself is a white- 
water river, this name being applied to those waters 
which are of a pale yellowish olive-colour. This colour 
does not seem to depend entirely on free earthy matter, 
but rather on some colouring material held in solution ; 
for in lakes and inlets, where the waters are undisturbed 
and can deposit all their sediment, they still retain the 
colour. 
The waters of the Amazon continue of the same 
coloiu* up to the mouth of the Uaycali, when they be- 
come blue or transparent, and the white waters are ex- 
tended up that branch. 
