After dividing all that belongs to astronomy, botany, zoology, the political description of New Spain, and the history of the ancient civilizations of certain New World nations into separate works, many general results and local descriptions remained left over, which I could still collect into separate treatises. I had prepared several during my journey; on races in South America; on the Orinoco missions; on what hinders civilization in the torrid zone, from the climate to the vegetation; the landscape of the Andes compared to the Swiss Alps; analogies between the rocks of the two continents; the air in the equinoctial regions, etc. I had left Europe with the firm decision not to write what is usually called the historical narrative of a journey, but just to publish the results of my researches. I had arranged the facts not as they presented themselves individually but in their relationships to each other. Surrounded by such powerful nature, and all the things seen every day, the traveler feels no inclination to record in a journal all the ordinary details of life that happen to him.

The jungle that covers the steep slope of the Santa María mountain is one of the densest I have ever seen. The trees are amazingly tall and thick. Under the dark green and matted canopy of leaves it always seems far darker than under our pine, oak and beech woods. Despite the temperature, it would seem that the air cannot absorb all the water emanating from the ground, the leaves and trunks of the trees with their tangle of orchids, peperomias and other succulent plants.

The Indians enter the caves once a year near midsummer with poles to destroy most of the nests. Several thousand birds are killed; the older ones hover over their heads to defend their young, screaming horribly. The young, called los pollos del guàcharo, fall to the ground and are cut open on the spot. Their peritoneum is loaded with fat; a layer of fat reaches from the abdomen to the anus, forming a kind of wad between the bird's legs. During this period, called the cosecha de la manteca (oil harvest) in Caripe, the Indians build palm-leaf huts near the entrance and in the cave vestibule itself. We could see their remains. With a brushwood fire they melt the fat of the young birds just killed and pour it into clay pots. This fat is known as butter or guàcharo oil; it is semi-liquid, clear and odorless, and so pure that it lasts for a year without going rancid. In the Caripe convent kitchen they only use fat from this cave, and the food never had a disagreeable taste or smell thanks to this fat.

From the mouth of the Meta, the Orinoco seemed freer of shoals and rocks. We navigated in a canal 500 toises wide. The Indians stayed in the pirogue, rowing without towing or pushing it with their hands, tiring us with their wild screams. It was already dark when we found ourselves by the Raudal de Tabaje. The Indians did not want to risk crossing the cataract and so we spent the night on land on a site that was extremely uncomfortable, on a rock bench with a steep slope sheltering a cloud of bats in crevices. All night we heard the cries of jaguars. Our dog answered by howling back. The deafening noise of the Orinoco waterfalls contrasted with the thunder grumbling over the jungle.