As far as the rock of Gayta, that is, up to the beginning of the great retama plain, the Tenerife peak is covered in beautiful vegetation, with no traces of recent devastations. But hardly have you entered the plain littered with pumice-stone than the countryside changes dramatically; at every step you trip over enormous obsidian blocks thrown down by the volcano. Everything here betrays a deep solitude. A few goats and rabbits are the only signs of life in this high plain. From up here the island becomes an immense heap of burned matter surrounded by a narrow fringe of vegetation.

There we met the district corregidor, Don Alejandro Mejía, an amiable and well-educated man. He gave us three Indians who would cut us a path through the jungle with machetes. In this country, where people rarely travel, the vegetation is so fertile that a man on horseback can barely make his way along the jungle paths tangled with liana and branches during the rainy season. To our great annoyance the Catuaro missionary insisted on leading us to Cariaco, and we could not decline his offer. He told us a dreadful story. The independence movement, which had nearly broken out in 1798, had been preceded and followed by trouble among the slaves at Cariaco. An unfortunate negro had been condemned to death and our host was going to Cariaco to give him some spiritual comfort. How tedious this journey became. We could not escape talking about 'the necessity of slavery, the innate wickedness of the blacks, and how slavery benefited Christians'!

Having outlined the general aim, I will now briefly glance at the collections and observations we made. The maritime war during our stay in America made communications with Europe very uncertain and, in order for us to avoid losses, forced us to make three different collections. The first we sent to Spain and France, the second to the United States and England, and the third, the most considerable, remained constantly with us. Towards the end of our journey this last collection formed forty-two boxes containing a herbal of 6, equinoctial plants, seeds, shells and insects, and geological specimens from Chimborazo, New Granada and the banks of the Amazon, never seen in Europe before. After our journey up the Orinoco, we left a part of this collection in Cuba in order to pick it up on our return from Peru and Mexico. The rest followed us for five years along the Andes chain, across New Spain, from the Pacific shores to the West Indian seas. The carrying of these objects, and the minute care they required, created unbelievable difficulties, quite unknown in the wildest parts of Europe. Our progress was often held up by having to drag after us for five and six months at a time from twelve to twenty loaded mules, change these mules every eight to ten days, and oversee the Indians employed on these caravans. Often, to add new geological specimens to our collections, we had to throw away others collected long before. Such sacrifices were no less painful than what we lost through accidents. We learned too late that the warm humidity and the frequent falls of our mules prevented us from preserving our hastily prepared animal skins and the fish and reptiles in alcohol. I note these banal details to show that we had no means of bringing back many of the objects of zoological and comparative anatomical interest whose descriptions and drawings we have published. Despite these obstacles, and the expenses entailed, I was pleased that I had decided before leaving to send duplicates of all we had collected to Europe. It is worth repeating that in seas infested with pirates a traveler can only be sure of what he takes with him. Only a few duplicates that we sent from America were saved, most fell into the hands of people ignorant of the sciences. When a ship is held in a foreign port, boxes containing dried plants or stones are merely forgotten, and not sent on as indicated to scientific men. Our geological collections taken in the Pacific had a happier fate. We are for their safety to the generous work of Sir Joseph Banks, President of the Royal Society of London, who, in the middle of Europe's political turmoils, has struggled ceaselessly to consolidate the ties that unite scientific men of all nations.

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.