The young birds which fall to the ground are opened on the spot. Their peritoneum is covered with a thick layer of fat, extending from the abdomen to the anus, and forming a kind of cushion between the legs. At the time called at Caripe the oil harvest, the Indians build themselves huts of palm leaves outside the cavern, and then light fires of brushwood, over which they hang clay pots filled with the fat of the young birds recently killed. This fat, known under the name of the Guacharo oil or butter, is half-liquid, transparent, without smell, and so pure that it can be kept a year without turning rancid.

Humboldt continues: "We passed fifteen days in the Caripe valley, situated at a height of 952 Castilian varas above the sea-level, and inhabited by naked Indians. We saw some black monkeys with red beards. We had the satisfaction of being treated with the greatest kindness by the Capuchin monks and the missionaries living amongst these semi-barbarous people."

Itinerary of Humboldt's route in equinoctial America
Engraved by Morieu.

From the Caripe valley the two travellers went back to Cumana by way of the Santa Maria Mountains and the Catuaro missions, and on the 21st November they arrived—having come by sea—at Caracas, a town situated in the midst of a valley rich in cocoa, cotton, and coffee, yet with a European climate.

Humboldt turned his stay at Caracas to account by studying the light of the stars of the southern hemisphere, for he had noticed that several, notably the Altar, the Feet of the Centaur, and others, seemed to have changed since the time of La Caille.

At the same time he put his collections in order, despatching part of them to Europe, and most thoroughly examined some rocks, with a view to ascertaining of what materials the earth's crust was here composed.

After having explored the neighbourhood of Caracas, and ascended the Silla, which, although close to the town, had never been scaled by any native, Humboldt and Bonpland went to Valencia, along the shores of a lake called Tacarigua by the Indians, and exceeding in size that of Neufchâtel in Switzerland. Nothing could give any idea of the richness and variety of the vegetation. But the interest of the lake consists not only in its picturesque and romantic beauty; the gradual decrease in the volume of its waters attracted the attention of Humboldt, who attributed it to the reckless cutting down of the forests in its neighbourhood, resulting in the exhaustion of its sources.

Near this lake Humboldt received proof of the truth of the accounts he had heard of an extraordinary tree, the palo de la vaca, or cow-tree, which yields a balsamic and very nutritive milk, drawn off from incisions made in the bark.

The most arduous part of the trip began at Porto Caballo, at the entrance to the llanos, or perfectly flat plains stretching between the hills of the coast and the Orinoco valley.

"I am not sure," says Humboldt, "that the first sight of the llanos is not as surprising as that of the Andes."

Nothing in fact could be more striking than this sea of grass, from which whirls of dust rise up continually, although not a breath of wind is felt at Calabozo, in the centre of this vast plain. Humboldt first tested the power of the gymnotus, or electric eel, large numbers of which are met with in all the tributaries of the Orinoco. The Indians, who were afraid of exposing themselves to the electric discharge of these singular creatures, proposed sending some horses into the marsh containing them.

"The extraordinary noise made by the shoes of the horses," says Humboldt, "made the eels come out of the ooze and prepare for battle. The yellowish livid gymnoti, resembling serpents, swam on the top of the water, and squeezed themselves under the bodies of the quadrupeds which had disturbed them. The struggle which ensued between animals so differently constituted presented a very striking spectacle. The Indians, armed with harpoons and long canes, surrounded the pond on every side, and even climbed into the trees, the branches of which stretched horizontally over the water. Their wild cries, as they brandished their long sticks, prevented the horses from running away and getting back to the shores of the pond; whilst the eels, driven mad by the noise, defended themselves by repeated discharges from their electric batteries. For a long time they appeared victorious, and some horses succumbed to the violence of the repeated shocks which they received upon their vital organs from every side. They were stunned, and sank beneath the water.

"Others, panting for breath, with manes erect, and wild eyes full of the keenest suffering, tried to fly from the scene, but the merciless Indians drove them back into the water. A very few, who succeeded in eluding the vigilance of the guards, regained the bank, stumbling at every step, and lay down upon the sand, exhausted with fatigue, every limb paralyzed from the electric shocks received from the eels.

"I never remember receiving a more terrible shock from a Leyden jar than I did from a gymnotus on which I accidentally trod just after it came out of the water."

The astronomic position of Calabozo having been determined, Humboldt and Bonpland resumed their journey to the Orinoco. The Uriticu, with its numerous and ferocious crocodiles, and the Apure, one of the tributaries of the Orinoco, the banks of which are covered with a luxuriant vegetation such as is only met with in the tropics, were successively crossed or descended.