338 
THE BIO ATABArO. 
situations of the Christian settlements on the Atahapo, the 
Guayavero, and the Caqueta.* 
Everything changes on entering the Bio Atahapo ; the 
constitution of the atmosphere, the colour of the waters, and 
the form of the trees that coyer the shore. You no longer 
suffer during the day the torment of mosquitos; and the long- 
legged gnats (zancudos) become rare during the night. Be- 
yond the mission of San Fernando these nocturnal insects 
disappear altogether. The water of the Orinoco is turbid, 
and loaded with earthy matter ; and in the coves, from the 
accumulation of dead crocodiles and other putrescent sub- 
stances, it diffuses a musky and faint smell. _ AYe were some- 
times obliged to strain this water through a linen cloth before 
we drank it. The water of the Atabapo, on the contrary, is 
pure, agreeable to the taste, without any trace of smell, brown- 
ish by reflected, and of a pale yellow by transmitted light. 
The people call it light, in opposition to the heavy and 
turbid waters of the Orinoco. Its temperature is generally 
two degrees, and when you approach the mouth of the Bio 
Temi, three degrees, cooler than the temperature of the Upper 
Orinoco. After having been compelled during a whole year 
to drink water at 27° or 28°, a lowering of a few degrees i» 
the temperature produces a very agreeable sensation. 1 
think this lowering of the temperature may be attributed 
to the river being less broad, and without the sandy beachi 
the heat of which, at the Orinoco, is by day more than 50 , 
and also to the thick shade of the forests which are traversed 
by the Atabapo, the Temi, the Tuamini, and the Guainia, or 
Bio Negro. . 
The extreme purity of the black waters is proved by their 
limpidity, their transparency, and the clearness with wine 
they reflect the images and colours of surrounding objects- 
The smallest fish are visible in them at a depth of twenty or 
thirty feet ; and most commonly the bottom of the river 
may be distinguished, which is not a yellowish or brownish 
mud, like the colour of the water, but a quartzose » nC 
granitic sand of dazzling whiteness. Nothing can be com- 
pared to the beauty of the banks of the Atabapo. Loade 
with plants, among which rise the palms with feathery 
leaves; the banks are reflected in the waters, and tm 
* The Caqueta bears, lower down, the name of the Yu pure. 
