During my navigation up the South American rivers, and over land, I had written a very brief itinerary where I described on the spot what I saw when I climbed the summit of a volcano or any other mountain, but I did not continue my notes in the towns, or when busy with something else. When I did take notes my only motive was to preserve those fugitive ideas that occur to a naturalist, to make a temporary collection of facts and first impressions But I did not think at the time that these jotted-down notes would form the basis of a work offered to the public. I thought that my journey might add something to science, but would not include those colorful details that are the main interest in journeys.

The last days of our crossing were not as peaceful as the mild climate and calm ocean had led us to hope. We were not disturbed by the dangers of the deep, but by the presence of a malignant fever that developed as we approached the West Indies. Between the overcrowded decks the heat was unbearable; the thermometer stayed at 36'C. Two sailors, several passengers and, strangely, two blacks from the Guinean coast and a mulatto child were attacked by an illness that threatened to turn into an epidemic. The symptoms were not as serious in all the sick; but some of them, even among the most robust, became delirious on the second day and lost all body strength. With that indifference which on passenger ships affects everything that is not to do with the ship's movements and speed, the captain did not for a moment think of applying the simplest remedies. He did not fumigate. A phlegmatic and ignorant Galician surgeon prescribed bleedings, attributing the fever to what he called the heat and corruption of blood. There was not an ounce of quinine on board and we, on boarding, had forgotten to bring a supply, more concerned for our instruments than for our health as we had not predicted that a Spanish ship would be without this Peruvian bark febrifuge.

We observed that fern trees are usually far rarer than palm trees. Nature has limited them to temperate, humid and shady places. They shun the direct rays of the sun and while the pumos, corypha of the steppes, and other American palms prefer the naked, burning plains these tree fern, which seen from afar look like palms, maintain the character and habits of cryptogams. They prefer solitary places, shade, humidity and damp. Sometimes you find them on the coast, but only when protected by thick shade.

Until the middle of the last century the mountains surrounding the Aragua valley were covered in forests. Huge trees of the mimosa, ceiba and fig families shaded the lake shore and kept it cool. The sparsely populated plain was invaded by shrubs, fallen tree trunks and parasitical plants, and was covered in thick grass so that heat was not lost as easily as from cultivated ground, which is not sheltered from the sun's rays. When the trees are felled, and sugar cane, indigo and cotton are planted, springs and natural supplies to the lake dry up. It is hard to form a fair idea of the enormous amount of evaporation taking place in the torrid zone, especially in a valley surrounded by steep mountains where maritime breezes blow, and whose ground is completely flat as if leveled by water. The heat prevailing on the lake shore is comparable to that in Naples and Sicily.

The location of the town of Santa Cruz is similar to La °, the busiest port in the province of Caracas. The heat is excessive in both places, but Santa Cruz is sadder. On a deserted sandy beach, houses of a dazzling white with flat roofs and windows without panes lie close to a rocky cliff stripped of vegetation. A fine stone quay and public walk planted with poplars are the only attraction in that monotonous picture. From Santa Cruz the peak seems far less picturesque than it does from the port of Orotava. There a smiling and richly cultivated plain contrasts with the wild appearance of the volcano. From the groves of palm and banana trees on the shore to the region of strawberry trees, laurels and pine the volcanic rock is covered with luxuriant vegetation. It is easy to see why the inhabitants of the beautiful climates of Greece and Italy thought they had discovered one of the Fortunate Isles on the western part of Tenerife. The eastern Santa Cruz side is everywhere marked with sterility.