With the Maypures Indians, it is the women who decorate the vessels, clean the clay by washing it several times; then they shape it into cylinders and mould even the largest jars with their hands. The American Indians never discovered the potter's wheel.

The San Francisco mission, situated on the left bank of the Casiquiare, was named after one of the leaders of the boundary expedition, Don Joseph Solano. This educated officer never got any further than San Fernando de Atabapo; he had never seen the Río Negro waters or the Casiquiare, or the Orinoco east of the Guaviare. Ignorance of the Spanish language drove geographers to locate erroneously on the famous La Cruz Olmedilla map the 400 league route made by Joseph Solano to the sources of the Orinoco. The San Francisco mission was founded not by monks but by military authorities. Following the boundary expedition, villages were built wherever an officer or a corporal stopped with his soldiers. Some of the Indians withdrew and remained independent; others, whose chiefs were caught, joined the missions. Where there was no church they were happy to raise a great red wooden cross, and to build a casa fuerte, that is, a house with long beams placed horizontally on top of each other, next to it. This house had two floors; upstairs were placed small cannons; downstairs two soldiers lived, served by Indian families. Tamed Indians established themselves around the casa fuerte. In the event of an attack soldiers would gather the Indians together by sounding the horn, or the baked-earth botuto. These were the nineteen so-called Christian establishments founded by Don Antonio Santos. Military posts had no effect in civilizing the Indians living there. They figured on maps and in mission works as pueblos (villages) and as reducciones apostòlicas.

The little village of Uruana is harder to govern than most other missions. The Otomacs are restless, noisy, and extreme in their passions. They not only adore the fermented liquors of cassava, maize and palm wine, but also get very drunk, to the point of madness, with niopo powder. They gather the long pods of a mimosa, which we have made known as Acacia niopo; they cut them into little pieces, dampen them and let them ferment. When the macerated plants turn black they are crushed into a paste and mixed with cassava flour and lime obtained from burning the shell of a helix. They cook this mass on a grill of hardwood above a fire. The hardened pate looks like little cakes. When they want to use it they crumble it into a powder and put it on a small plate. The Otomac holds this plate with one hand while through his nose, along the forked bone of a bird whose two extremities end up in his nostrils, he breathes in the niopo. I sent some niopo and all the necessary instruments to Fourcroy in Paris. Niopo is so stimulating that a tiny portion produces violent sneezing in those not used to it. Father Gumilla wrote: 'The diabolic powder of the Otomacs makes them drunk through their nostrils, deprives them of reason for several hours, and makes them mad in battle.

Our missionary, however, seemed quite satisfied with his situation. He treated the Indians well; his mission prospered, and he enthused about the water, the bananas and the milk of this place. The sight of our instruments, our books and dried plants made him smile sarcastically; and he acknowledged with the naiveté peculiar to the inhabitants of these countries that his greatest pleasure in life, even including sleep, was eating good beef, carne de vaca; thus does sensuality triumph when there is nothing to occupy the mind. Our host often enjoined us to visit the cow he had bought, and the following day, at dawn, we could not avoid watching his cow being slaughtered in the manner of the country, that is, cutting its hamstrings before plunging a long knife into the vertebra of its neck. Disgusting as this was, it did teach us about the immense skill of the Chaima Indians, who, numbering eight, managed to cut the animal up into little pieces in less than twenty minutes.