The Pimichino flows into the Rio-Negro, which is in its turn a tributary of the Amazon.
Humboldt and Bonpland went down the Rio-Negro as far as San Carlos, and then up the Casiquiaro, an important branch of the Orinoco, which connects it with the Rio-Negro. The shores of the Casiquiaro are inhabited by the Ydapaminores, who live entirely on smoked ants.
Lastly, the travellers went up the Orinoco nearly to its source, at the foot of the Duida volcano, where their further progress was stopped by the hostility of the Guaharibos and the Guaica Indians, who were skilful marksmen with the bow and arrow. Here was discovered the famous El Dorado lake, with its floating islets of talc.
Thus was finally solved the problem of the junction of the Orinoco and the Marañon, which takes place on the borders of the Spanish and Portuguese territories, two degrees above the equator.
The two travellers then floated with the current down the Orinoco, traversing by this means five hundred leagues in twenty-five days, after which they halted for three weeks at Angostura, to tide over the time of the great heat, when fever is prevalent, regaining Cumana in October, 1800.
"My health," says Humboldt, "was proof against the fatigue of a journey of more than 1300 leagues, but my poor comrade Bonpland, was, immediately on his return, seized with fever and sickness, which nearly proved fatal. A constitution of exceptional vigour is necessary to enable a traveller to bear the fatigue, privations, and interruptions of every kind with which he has to contend in these unhealthy districts, with impunity. We were constantly surrounded by voracious tigers and crocodiles, stung by venomous mosquitoes and ants, with no food for three months but water, bananas, fish, and tapioca, now crossing the territory of the earth-eating Otomaques, now wandering through the desolate regions below the equator, where not a human creature is seen for 130 leagues. Few indeed are those who survive such perils and such exertions, fewer still are those who, having surmounted them, have sufficient courage and strength to encounter them a second time."
We have seen what an important geographical discovery rewarded the perseverance of the explorers who had completed the examination of the whole of the district north of the Amazon, between Popayan and the mountains of French Guiana. The results obtained in other branches of science were no less novel and important.
Humboldt had discovered that there exists amongst the Indians of the Upper Orinoco and the Rio Negro a race with extremely fair complexions, differing entirely from the natives of the coast. He also noticed the curious tribe of the Otomaques.
"These people," he says "who disfigure their bodies with hideous paintings, eat nothing but loam for some three months, when the height of the Orinoco cuts them off from the turtles which form their ordinary food. Some monks say they mix earth with the fat of crocodiles' tails, but this is a very false assertion. We saw provisions made of unadulterated earth, prepared only by slow roasting and moistening with water."
Amongst the most curious of the discoveries made by Humboldt, we must mention that of the "curare," the virulent poison which he saw manufactured by the Catarapeni and Maquiritare Indians, and a specimen of which he sent to the Institute with the "dapiche," a variety of Indian rubber hitherto unknown, being the gum which exudes spontaneously from the roots of the trees known as "jacio" and "cucurma," and dries underground.