ceeding to Guayaquil, and in that case the voyage on the Pacific would be extremely lingering, as they would have to sail against contrary winds and currents. The persons they consulted all agreed that the journey by land along the Cordilleras, by Santa Fé de Bogota, Popayan, Quito, and Caxamarca, would be preferable to the sea-voyage, and would furnish an immense field for exploration. The predilection of Europeans for the cold and temperate climate that prevailed on the back of the Andes, gave further weight to these counsels. The distances were known, but Humboldt was deceived with respect to the time it would take to traverse them on mules' backs. He did not imagine that it would require over eighteen months to go from Carthagena to Lima. Notwithstanding this delay, or rather owing to the slowness with which he passed through Cundinamarca, the provinces of Popayan, and Quito, he did not regret having sacrificed the passage of the isthmus to the route of Bogota, for every step of the journey was full of interest both geographically and botanically. This change of direction gave him occasion to trace the map of the Rio Magdalena, to determine astronomically the position of eighty points situated in the inland country between Cartha gena, Popayan, and the upper course of the river Amazon and Lima, to discover an error in the longitude of Quito, to collect several thousand new plants, and to ob serve on a vast scale the relations between the rocks of syenitic porphyry and trachyte, with the fire of vol

canoes.

During the six days of their stay at Carthagena their most interesting excursions were to the Boca Grande, and the hill of Popa. A small portion of hilly land sepa

rated the town of Carthagena and the islet of Manga from the Cienega de Tesca. These hills, some of which were more than five hundred feet high, commanded the town. The Castillo de San Lazaro was seen from afar rising like a great rocky pyramid; when examined nearer its fortifications were not very formidable. Layers of clay and sand were covered with bricks, and furnished a kind of construction which had little stability. The Cerro de Santa Maria de la Popa, crowned by a convent and some batteries, rose above the fort of San Lazaro, and was worthy of more solid and extensive works. The image. of the Virgin, preserved in the church of the convent, had been long revered by mariners. The view from the Popa was extensive and varied, and the windings and rents of the coast gave it a peculiar character. Humboldt was assured that sometimes from the windows of the convent, and even in the open sea, before the fort of Boca Chica, the snowy tops of the Sierra Nevada de Santa Marta were discernible.

In order to avoid the excessive heats, and the diseases which prevailed during the summer at Carthagena, the travellers removed inland to the village of Turbaco. This small Indian village stood on a hill, at the entrance of a majestic forest, which extended towards the south and the east as far as the canal of Mahates and the river Magdalena. The houses were mostly built of bamboos, and covered with palm leaves. Here and there limpid springs rose out of the calcareous rock, which contained numerous fragments of petrified coral, and were shaded by the splendid foliage of the anacardium caracoli, a tree of colossal size, to which the natives attributed the property of attracting from great distances the vapours float

212

THE VOLCANOES OF TURBACO.

ing in the atmosphere. As the soil of Turbaco was more than nine hundred feet above the level of the ocean, a delightful coolness prevailed, especially during the night.

The Indians of Turbaco, who accompanied the travellers in their herbalizations, spoke of a marshy country, situated in a forest of palm trees, and called by the Creoles the Little Volcanoes. They related that, according to a tradition still existing among them, this spot had formerly been in flames; but that a very pious man, a vicar of the village, had succeeded by his frequent aspersions of holy water in extinguishing the subterraneous fire. They added, that, since this time, the fiery volcano had become a water volcano. From their long residence in the Spanish colonies, the travellers were familiar with the strange and marvellous stories, which the natives eagerly recited to fix the attention of travellers on the phenomena of nature; though they knew, that these stories were in general less indebted for their currency to the superstition of the Indians, than to that of the whites, the mulattoes, and the African slaves; and that the reveries of a few individuals, who reasoned on the progressive changes of the surface of the globe, gradually assumed the character of historical traditions. Without giving any credit to the existence of an extent of country in a former state of ignition, they were conducted by the Indians to the Volcanoes; and this excursion made them acquainted with phenomena, much more important than any they could have expected.

The Volcanoes were situated to the east of the village of Turbaco, in a thick forest, abounding with balsam of Tolu trees. The ground rose gradually two hundred

and fifty or three hundred feet above the village of Turbaco; but as it was everywhere covered with vegetation, it was not possible to distinguish the nature of the rocks that reposed on the shelly calcareous soil.

In the centre of a vast plain were eighteen or twenty small cones, in height not above twenty-five feet. These cones were formed of a blackish gray clay, and had an opening at their summits filled with water. On approaching these small craters, a hollow but very distinct sound was heard at intervals, fifteen or eighteen seconds previous to the disengagement of a great quantity of air. The force with which this air rose above the surface of the water led them to suppose, that it underwent a great pressure in the bowels of the earth. Humboldt generally reckoned five explosions in two minutes; and this phenomenon was often attended with a muddy ejection. The Indians assured him, that the forms of the cones suffered no visible change in a great number of years; but the ascending force of the gas, and the frequency of the explosions, appeared to vary according to the seasons. He found by analyses made by means both of nitrous gas and of phosphorus, that the disengaged air scarcely contained a thousandth part of oxygen. It was azotic gas, much more pure than that which is generally prepared in laboratories.

CHAPTER VI.

COLOMBIA AND PERU.

COMPLETING about the end of April the observations they proposed to make at the northern extremity of the torrid zone, Humboldt and Bonpland were on the point of proceeding to Vera Cruz with the squadron of Admiral Ariztizabal; but being misled by false intelligence respecting the expedition of Captain Baudin, they were induced to relinquish the project of passing through Mexico on their way to the Philippine Islands. The public journals announced that two French sloops, the "Géographe" and the "Naturaliste," had sailed for Cape Horn; that they were to proceed along the coasts of Chili and Peru, and thence to New Holland. This intelligence revived in Humboldt's mind all the projects he had formed during his stay in Paris, when he solicited the Directory to hasten the departure of Captain Baudin. The travellers at once set to work and divided their precious herbals into three portions, to avoid exposing to the risks of a long voyage the objects they had obtained with so much difficulty on the banks of the Orinoco, the Atabapo, and the Rio Negro. They sent one collection by way of England to Germany, another by way of Cadiz to France, and a third remained at