The morning was fresh and beautiful. For thirty-six days we had been locked up in a narrow canoe which was so unsteady that standing up suddenly from your seat would have capsized it. We had cruelly suffered from insect bites, but we had survived this unhealthy climate, and had crossed the many waterfalls and dykes that block the rivers and make the journey more dangerous than crossing the seas, without sinking. After all that we had endured, it gives me pleasure to speak of the joy we felt in having reached a tributary of the Amazon, of having passed the isthmus that separates the two great river systems. The uninhabited banks of the Casiquiare, covered in jungle, busied my imagination. In this interior of a new continent you get used to seeing man as not essential to the natural order. The earth is overloaded with vegetation: nothing prevents its development. An immense layer of mould manifests the uninterrupted action of organic forces. Crocodile and boa are the masters of the river; jaguar, peccary, the dante and monkeys cross the jungle without fear of danger, established there in an ancient heritage. This view of a living nature where man is nothing is both odd and sad. Here, in a fertile land, in an eternal greenness, you search in vain for traces of man; you feel you are carried into a different world from the one you were born into.

On the morning of the 27th of February we visited the hot springs of La Trinchera, 3 leagues from Valencia. They flow more fully than any we had seen until then, forming a rivulet, which in the dry season maintains a depth of some 2 feet 8 inches of water. The carefully taken water temperature was 90.3°C. We had breakfast near the spring: our eggs were cooked in less than four minutes in the hot water. The rock from which the spring gushes is of real coarse-grained granite. Whenever the water evaporates in the air, it forms sediments and incrustations of carbonate of lime. The exuberance of the vegetation around the basin surprised us. Mimosas with delicate pinnate leaves, clusias and figs send their roots into the muddy ground, which is as hot as 85°C. Two currents flow down on parallel courses, and the Indians showed us how to prepare a bath of whatever temperature you want by opening a hole in the ground between the two streams. The sick, who come to La Trinchera to take steam baths, build a kind of framework with branches and thin reeds above the spring. They lie down naked on this frame, which, as far as I could see, was not very strong, perhaps even dangerous.

Both here and in the Río Negro the humidity and consequent quantity of insects make all agriculture impossible. Everywhere you see large ants, which march in packed columns and devour all cultivated plants that are soft and juicy, while in the jungle they can find only woody stalks. If a missionary wants to plant lettuce, or any other European vegetable, he has to hang his garden in the air. He fills an old canoe with good earth and hangs it 4 feet above the ground with rope made from chiquichiqui palm or, more commonly, rests it on some scaffolding.

During the night we had left the Orinoco waters almost without realizing it. At sunrise we found ourselves in a new country, on the banks of a river whose name we had hardly heard mentioned, and which would lead us after a foot journey over Pimichín to the Río Negro on the Brazilian frontier. The father superior of the San Fernando mission said to us: 'First you must go up the Atabapo, then the Temi, and finally the Tuamini. If the black-water current is too strong to do this the guides will take you over flooded land through the jungle. In that deserted zone between the Orinoco and the Río Negro you will meet only two monks established there. In Javita you will find people to carry your canoe over land in four days to Caìo Pimichín. If the canoe is not wrecked go straight down the Río Negro to the fort of San Carlos, then go up the Casiquiare and in a month you will reach San Fernando along the Upper Orinoco. That was the plan drawn up for us, which we carried out, without danger, in thirty-three days. The bends are such in this labyrinth of rivers that without the map which I have drawn it would be impossible to picture the route we took. In the first part of this journey from east to west you find the famous bifurcations that have given rise to so many disputes, and whose location I was the first to establish through astronomic observations. One arm of the Orinoco, the Casiquiare (108) running north to south, pours into the Guainia or Río Negro, which in turn joins the Maraìon or Amazon.

MEsmeralda is the most famous place on the Orinoco for the making of the active poison that is used in war, out hunting and, surprisingly, as a remedy against gastric illnesses. The poison of the Amazonian Tikuna, the upas-tieute of Java and the Guianan curare are the most poisonous substances known. Already by the sixteenth century Raleigh had heard the word urari spoken, signifying a vegetable substance used to poison arrows. However, nothing was known for sure in Europe about this poison.

The road from Río Blanco to Batabanò crossed uncultivated land, half covered in jungle, with wild indigo and cotton trees in the clearings. Several friends, including Seìor de Mendoza, captain of Valpraíso harbor, and brother of the famous astronomer who had lived so long in London, accompanied us to Portrero de Mopox. While herborizing we found a new palm tree with fan leaves (Corypha maritima).