Some of the rivers flowing into Lake Valencia come from thermal springs, worthy of special note. These springs gush out at three points from the coastal granitic chain at Onoto, Mariara and Las Trincheras. I was only able to carefully examine the physical and geological relations of the thermal waters of Mariara and Las Trincheras. All the springs contain small amounts of sulphuretted hydrogen gas. The stink of rotten eggs, typical of this gas, could only be smelled very close to the spring. In one of the puddles, which had a temperature of 56.2°C, bubbles burst up at regular intervals of two to three minutes. I was not able to ignite the gas, not even the small amounts in the bubbles as they burst on the warm surface of the water, nor after collecting it in a bottle, despite feeling nausea caused more by the heat than by the gas. The water, when cold, is tasteless and quite drinkable.

That night Bonpland had a fever; but being brave, and gifted with that good character which a traveler should rank higher than anything else, he took up his work the next morning. The blow from the macana reached the crown of his head; he felt it for two to three months, up to our stay in Caracas. When he bent down to pick up plants he was several times made dizzy, which made us worry that some internal damage might have been done. Luckily our fears had no base and these alarming symptoms slowly vanished. The Cumanà inhabitants showed us the greatest kindness. We discovered that the mulatto came from one of the Indian villages round the great Maracaibo lake. He had served on a pirate ship from the island of Santo Domingo and, after a quarrel with the captain, had abandoned ship on the Cumanà coast. Why, after knocking one of us down, did he then try to steal a hat? In an interrogation his answers were so confused and stupid that we were unable to clear this matter up.

We stopped to observe the howler monkeys, which move in lines across the intricate branches linking the jungle trees in packs of thirty and forty. While watching this new spectacle we met a group of Indians on their way to the Caripe mountains. They were completely naked, like most Indians in these lands. Behind them came the women, laden with heavy packs, while all the men and boys were armed with bows and arrows. They walked in silence, staring at the ground. We would have liked to ask them if the Santa Cruz mission, where we hoped to spend the night, was far off. We were exhausted, and thirsty. The heat was increasing as the storm approached, and we had not found any springs. As the Indians invariably answered si padre and no padre we thought they understood a little Spanish. In their eyes every white is a monk, a padre. In the missions the color of the skin characterizes the monk more than the color of his habit. When we asked those Indians if Santa Cruz was far off they answered si or no so arbitrarily that we could make no sense of their answers. This made us angry, for their smiles and gestures showed that they would have liked to direct us as the jungle became thicker and thicker. We had to leave them; our guides, who spoke the Chaima language, lagged behind as the loaded mules kept falling into ravines.

The passengers on board the Pizarro who had not yet noticed the symptoms of this malady decided to leave the ship at the first port of call and await the arrival of another mail-boat to continue on to Cuba and Mexico. They felt the between decks were infected, and though it had not been proved that the fever was contagious I thought it more prudent to disembark at Cumana. It would have been a pity to put into port at Cumana and La Guaira without penetrating into a land so little explored by naturalists.

April 4th. It was our last day on the Apure river. During several days a plague of insects had been torturing our hands and faces. They were not mosquitoes but zancudos, which are really gnats. They appear after sunset; their proboscises are so long that they can pierce your hammock, your canvas and your clothes from the other side.

People in Turbaco out botanizing with us often spoke of a marshy land in the middle of a palm-tree forest that they called 'little volcanoes', los volcancitos. A village tradition claims that this land had once been in flames but that a good priest, known for his piety, cast holy water and put the underground fire out, changing the volcano of fire into a volcano of water, volcàn de agua. This tale reminded me of the geological disputes between Neptunists and Vulcanists of the last century. The local wise man, the Turbaco priest, assured us that the volcancitos were simply thermal waters swimming with sulphur, erupting during storms with 'moans'. We had been too long in the Spanish colonies not to doubt these marvellous fantasies coming more from superstitious whites than from Indians, half-castes and African slaves. We were led to the volcancitos in the jungle by Indians and found salses, or air volcanoes.

The ground of the island rises to form an amphitheatre and, as in Peru and Mexico, contains in miniature all the possible climates, from African heat to alpine cold. (14) The mean temperatures of Santa Cruz, the port of Orotava, Orotava itself and La Laguna form a descending series. In southern Europe the change of seasons is too strongly felt to offer the same advantages. Tenerife on the other hand, on the threshold of the Tropics and a few days' journey from Spain, benefits from a good part of what nature has lavished in the Tropics. Its flora include the beautiful and imposing bananas and palms. He who is able to feel nature's beauty finds in this precious island a far more effective remedy than the climate. Nowhere else in the world seems more appropriate to dissipate melancholy and restore peace to troubled minds than Tenerife and Madeira. These effects are due not only to the magnificent situation and to the purity of air, but above all to the absence of slavery, which so deeply revolts us in all those places where Europeans have brought what they call their 'enlightenment and their 'commerce' to their colonies