May 1st. The Indians wanted to leave long before sunrise. We got up before them because we had hoped to see some stars, but in this humid, thick-jungled zone the nights were getting darker and darker as we approached the Río Negro and the interior of Brazil. We stayed in the river until dawn, fearing to get lost in the trees. But as soon as the sun rose we went through the flooded jungle to avoid the strong current. We reached the confluence of the Temi and Tuamini and went upstream on the latter south-west, reaching the Javita mission on the banks of the Tuamini at about eleven in the morning. It was at this Christian mission that we hoped to find help in carrying our pirogue to the Río Negro. A minor accident shows how fearful the little sagouin monkeys are. The noise of the 'blowers' seared one of them and it fell into the water. These monkeys can hardly swim, and we just managed to save it.

To give some variety to my work I have often interrupted the historical narrative with straightforward descriptions. I begin by describing the phenomena as they appeared to me, then I consider their individual relations to the whole.

If you compare the Río Negro with the Amazon, the River Plate or the Orinoco it is but a river of the second order. Possessing it has been, for centuries, of great political interest for the Spanish Government because it affords its rivals, the Portuguese, easy access into the Guianan missions to worry the Capitanía-General of Caracas in its southern limits. Three hundred years have passed in pointless territorial disputes. In different times, according to their degree of civilization, people have leaned either on papal authority or on astronomy. As they have generally been keener to prolong this dispute rather than solve it, only nautical science and geography have gained anything. When the affairs of Paraguay and the possession of the Sacramento colony became important for the two Courts of Madrid and Lisbon, commissioners were sent out to study the boundaries of the Orinoco, Amazon and River Plate. Besides the idle, who filled archives with their complaints and lawsuits, there were a few educated engineers and some naval officers acquainted with the means of determining the position of a place. The little we knew up to the of the last century about the geography of the interior of the Continent is due to these hard-working men. It is pleasing to remind ourselves that the sciences gained accidentally from these border commissions, often forgotten by the states that sent them out.

In the lands of the Río Negro Indians we found several of those green stones known as 'Amazon stones' because Indians claim that they come from a country of 'women without men', or 'women living alone'. Superstition attaches great importance to these stones, which are worn as amulets round the neck as popular belief claims they protect wearers from nervous diseases, fevers and poisonous snake bites. Because of this they have for centuries been traded between the Indians of the northern Orinoco and those in the south. The Caribs made them known on the coast. Up to a few years ago during debates about quinine these green stones were considered an efficient febrifuge in enlightened Europe; if we can count on the credulity of Europeans, there is nothing odd about Spanish colonizers appreciating these amulets as much as the Indians, or that these stones are sold at high prices. Usually they are shaped into cylinders with holes down the sides, and covered in inscriptions and figures. But it is not today's Indians who have perforated holes in such hard stones or carved animals and fruit. This work suggests another, older culture. The actual inhabitants of the torrid zone are so ignorant of how to carve hard stone that they think the green stone comes from soft earth, and that it hardens when carved.

The Pizarro had orders to anchor off the island of Lanzarote, of the seven large Canary Islands, to find out if the English werestill blockading the Santa Cruz bay. From the 15th we were dubious aboutwhich route to follow. Finally, on the 16th, at two in the afternoon, we sighted land, which looked like alittle cloud stuck on the horizon. At five, with the sun very low, we couldclearly see the island of Lanzarote before us.

May 10th. Overnight our canoe was loaded and we set off a little before dawn to go up the Río Negro to the mouth of the Casiquiare and begin our researches on the true course of this river linking the Orinoco and Amazon. The morning was beautiful, but as the heat rose the sky began to cloud over. The air is so saturated with water in these forests that water bubbles become visible at the slightest increase of evaporation on the earth's surface. As there is no breeze the humid strata are not replaced and renewed by drier air. This clouded sky made us gloomier and gloomier. Through this humidity Bonpland -lost the plants he had collected; for my part I feared finding the same Río Negro mists in the Casiquiare valley. For more than half a century nobody in the missions has doubted the existence of communications between the two great river systems: the important aim of our journey was reduced to fixing the course of the Casiquiare by astronomic means, especially at its point of entry into the Río Negro, and its bifurcation with the Orinoco. Without sun or stars this aim would have been frustrated, and we would have been uselessly exposed to long, weary deprivation. Our travelling companions wanted to return by the shortest journey, along the Pimichín and its small rivers; but Bonpland preferred, like myself, to persist in the original plan we had traced out while crossing the Great Cataracts. We had already traveled by canoe from San Fernando de Apure to San Carlos along the Apure, Orinoco, Atabapo, Temi, Tuamini and Río Negro for over 180 leagues. In entering the Orinoco by the Casiquiare we still had some 320 leagues to cover from San Carlos to Angostura. It would have been a shame to let ourselves be discouraged by the fear of a cloudy sky and the Casiquiare mosquitoes. Our Indian pilot, who had recently visited Mandavaca, promised us sun and 'those great stars that eat up clouds' once we had left the black waters of the Guaviare. So we managed to carry out our first plan and returned to San Fernando along the Casiquiare. Luckily for our researches the Indian's prediction was fulfilled. The white waters brought us a clear sky, stars, mosquitoes and crocodiles.

On the road to the harbor we were struck by the countless phosphorescent insects (Cocuyo, Elater noctilucus). The grass, the branches and the leaves of trees all shone with that reddish, flickering light. It seemed as if the stars had fallen on to the savannah! In the poorest hut in the country fifteen cocuyos, placed in a gourd pierced with holes, give sufficient light to look for things at night. Shaking the gourd excites the animals and increases the luminous discs on their bodies. A young woman at Trinidad told us that during a long passage from the mainland she used the phosphorescent cocuyos when she wanted to nurse her baby at night. The captain of the ship would use only cocuyos lights so as not to attract pirates.