To the middle of the eighteenth century fields of sugar-canes and indigo extended between two rivulets, called Cuitimba and San Pedro. They were skirted by basaltic mountains, the structure of which seems to indicate, that all the country, in remote periods, has several times experienced the violent action of volcanoes. These fields, irrigated by art, belonged to the estate of San Pedro de Jorullo, or Xorullo, one of the largest and most valuable in the country. In the month of June, 1759, fearful rumbling noises were accompanied with frequent shocks of an earthquake, which succeeded each other at intervals for fifty or sixty days, and threw the inhabitants of the estate into the greatest consternation. From the beginning of the month of September, every thing seemed perfectly quiet, when in the night of the 28th of that month a terrible subterranean noise was heard anew. The frightened Indians fled to the mountains of Aguasarco. A space of three or four square miles, known by the name of Malpays, rose in the shape of a bladder. The boundaries of this rising are still distinguishable in the ruptured strata. The Malpays towards the edge is only 12 met. [13 yards] above the former level of the plain, called las playas de Jorullo; but the convexity of the ground increases progressively towards the centre, till it reaches the height of 160 met. [175 yards.]

They who witnessed this grand catastrophe from the top of Aguasarco assert, that they saw flames issue out of the ground for the space of more than half a league square; that fragments of red hot rocks were thrown to a prodigious height; and that through at thick cloud of ashes, illumined by the volcanic fire, and resembling a stormy sea, the softened crust of the earth was seen to swell up. The rivers of Cuitimba and San Pedro then precipitated themselves into the burning crevices. The decomposition of the water contributed to reanimate the flames, which were perceptible at the city of Pascuoro, though standing on a very wide plain 1400 met. [1530 yards] above the level of the playas de Jorullo. Eruptions of mud, particularly of the strata of clay including decomposed nodules of basaltes with concentric layers, seem to prove, that subterranean waters had no small part in this extraordinary revolution. Thousands of small cones, only two or three yards high, which the Indians call ovens, issued from the raised dome of the Malpays. Though the heat of these volcanic ovens has diminished greatly within these

fifteen years, according to the testimony of the Indians, I found the thermometer rise to 95° [if centig. 203° F.] in the crevices that emitted an aqueous vapour. Each little cone is a chimney, from which a thick smoke rises to the height of ten or fifteen met. [11 or 16 yards]. In several a subterranean noise is heard like that of some fluid boiling at no great depth.

Amid these ovens, in a fissure, the direction of which is from N. N. E. to S. S. E., six large hummocks rise 400 or 500 met. [440 or 550 yards] above the old level of the plain. This is the phenomenon of Monte Novo at Naples repeated several times in a row of volcanic hills. The loftiest of these huge hummocks, which reminded me of the district of Auvergue, is the large volcano of Jorullo. It is constantly burning, and has thrown out on the north side an immense quantity of scorified and basaltic lava, including fragments of primitive rocks. These grand eruptions of the central volcano continued till February 1760. In the succeeding years they became gradually less frequent. The Indians, alarmed by the horrible noise of the new volcano, at first deserted the villages for seven or eight leagues round the plain of Jorullo. In a few months they became familiar with the alarming sight, returned to their huts, and went down to the mountains of Aguasarco and Santa Ines, to admire the sheaves of fire thrown out by an infinite number of large and small volcanic openings. The ashes then covered the houses of Queretoro, more than 48 leagues [120 miles] in a right line from the place of the explosion. Though the subterranean fire appears to be in no great activity* at present, and the Malpays and the great volcano begin to be covered with vegetables, we found the air so heated by the little ovens, that in the shade, and at a considerable distance from the ground, the thermometer rose to 43° (109.4°F). This fact evinces, that there is no exaggeration in the report of some of the old Indians, who say, that the plains of Jorullo were uninha. bitable for several years, and even to a considerable distance from the ground raised up, on account of the excessive heat.

* In the bottom of the crater we found the heat of the air 47° [116.6°F. ] and in some places 58° and 60° [136·4° and 140°]. We had to pass over cracks exhaling sulphurous vapours, in which the thermometer rose to 85° [185]. From these cracks, and the heaps of scoriæ that cover considerable hollows, the descent into the crater is not without danger.

Near the cerro of Santa Ines the traveller is still shewn the channels of Cuitimba and San Pedro, the limpid waters of which formerly refreshed the sugar-canes on the estate of Don Andrew Pimental These springs were lost in the night of the 29th of September, 1759: but 2000 met. (near 2200 yards) to the westward, in the soil that has been elevated, two rivulets are seen to break out of the clayey dome of the furnaces, exhibiting themselves as thermal waters, in which ⚫ the thermometer rises to 52°7° (126·86°F.) The Indians still give these the names of San Pedro and Cuitimba, because in several parts of the Malpays large bodies of water are supposed to be heard running from east to west, from the mountains of Santa Ines to the estate of the Presentation. Near this estate is a brook that emits sulphuretted hydrogen gas: it is more than 7 met. (near 8 yards) wide, and is the most copious hidrosulphurous spring I ever saw.

In the opinion of the natives these extraordinary changes I have described, the crust of earth raised and cracked by volcanic fire, the mountains of scoriæ and ashes heaped up, are the works of monks; the greatest, no doubt, they ever produced in either hemisphere. Our Indian host, at the hut we inhabited in the plain of Jorullo, told us, that some missionary capuchins preached at the estate of San Pedro, and, not meeting a favourable reception, uttered the most horrible and complicated imprecations against this plain, then so beautiful and fertile. They prophesied, that the estate should first be swallowed up by flames issuing out of the bowels of the earth; and that the air should afterward be cooled to such a degree, that the neighbouring mountains should remain for ever covered with ice and snow. The first of these maledictions having been so fatally verified, the common people foresee in the gradual cooling of the volcano the presage of a perpetual winter. I have thought it right to mention this vulgar tradition, worthy a place in the epic poem of the jesuit Landivar, because it exhibits a striking feature of the manners and prejudices of these remote countries. It shews the active industry of a class of men, who, too frequently abusing the credulity of the people, and pretending to possess the power of suspending the immutable laws of nature, know how to avail themselves of every event for establishing their empire by the fear of physical evil.

The situation of the new volcano of Jorullo leads to a very cu

rious geological observation. It is well known to geographers, that there is in New Spain a line of great heights, or a narTOW zone included between the latitudes of 18° 59′ and 19° 12′, in which are all the summits of Anahuac that rise above the region of perpetual snow. These summits are either volcanoes still actually burning; or mountains, the form of which, as well as the nature of their rocks, renders it extremely probable, that they formerly contained subterranean fire. Setting out from the coast of the Gulf of Mexico, and proceeding westward, we find the peak of Oribaza, the two volcanoes of la Puebla, the Nevado de Teluca, the peak of Tancitaro, and the volcano of Colima. These great heights, instead of forming the ridge of the cordillera of Anahuac, and following its direction, which is from S. E. to N. W. are on the contrary in a line perpendicular to the axis of the great chain of mountains. It is certainly worthy of remark, that in the year 1759 the new volcano of Jorullo was formed in the continuation of this line, and on the same parallel as the ancient Mexican volcanoes.

A view of my plan of the environs of Jorullo will shew, that the six large hummocks have risen out of the earth on a vein that crosses the plain from the cerro of las Cuevas to the pichaco del Montero. The new mouths of Vesuvius too are found ranged along a fissure. Do not these analogies give us reason to suppose, that there exists in this part of Mexico, at a great depth within the earth, a fissure stretching from east to west through a space of 137 leagues [343 miles], and through which the volcanic fire has made its way at different times, bursting the outer crust of porphyritic rocks, from the coast of the Gulf of Mexico to the South Sea? Is this fissure prolonged to that little group of islands, called by Colluet the Archipelago of Regigedo, and round which, in the same parallel with the Mexican volcanoes, pumice-stone has been seen floating? Naturalists who distinguish the facts offered by descriptive mineralogy from theoretical reveries concerning the primitive state of our planet, will pardon me for having consigned these observations to the general map of New Spain, contained in the Mexican Atlas.

[Humboldt, as above.]

SECTION II.

Volcanoes of New Grenada.

THESE are chiefly to be met with on the summits of the enormous mountains in the viceroyalty of New Grenada, and in the neighbourhood of the city of Quito. These mountains constitute some of the grandest objects in natural geography, being many of them the loftiest on the face of the globe, while their volcanoes are of a most sublime and horrible character. The most celebrated of these elevated excavations are, Chimborazo, Cotopoxi, Sangai, Pichincha, and Antisanas; most of them, however, have expended themselves, except Sangai and Cotopoxi.

Chimborazo, the loftiest of the whole, about a hundred English miles to the south of Quito, and about ten to the north of Riobamba, is computed by Bouguer to be 3217 French toises, or 20,280 feet above the level of the sea; and consequently to be about 5,000 feet, or one quarter higher than Mount Blanc: its region of perpetual Show extends to about 2,400 feet from the summit.

The next loftiest mountain is Cotopaxi, estimated at about 18,509 feet, and situated at about twenty-five miles to the south east of Quito. Pichincha, lies still nearer to the capital, but in a southwesterly direction; and Altar and Sangai to the south-east.

This last is a páramo*, or vast desert, the summit always covered with snow. It is a perpetual volcano, whose fire is continually seen, and whose explosions are heard at a distance of forty leagues. The adjacent country is entirely barren, in consequence of being covered with the cinders ejected from its mouth. In this mountain rises the river Scagai, which being joined by the Upano, forms the Payra, a large river, which discharges itself into the river Maranon, or river of Amazons.

Cotopoxi is supposed to have become a volcano about the time when the Spaniards first invaded the country; and Ulloa asserts that it ejected stones of eight or nine feet in diameter, to a distance of more than nine miles. A new eruption occurred in 1743, which had been for some days preceded by a continual interior rumbling

* A Spanish term contracted from par eremo, eremitical, hermetical, hermit-like, solitary.-Editor.