level of the neighbouring plains, suddenly formed in the centre of a thousand small burning cones, thirty-six leagues from the shore, and forty-two leagues from any other volcano. This phenomenon remained unknown to the mineralogists and natural philosophers of Europe, though it took place but fifty years ago, and within six days journey of the capital of Mexico.

Descending from the central flat towards the coasts of the Pacific ocean, a vast plain extends from the hills of Aguasarco to the villages of Toipa and Patatlan, equally celebrated for their fine cotton plantations. Between the Picachos del Mortero and the Cerras de las Cuevas and de Cuiche, this plain is only from 820 to 880 yards above the level of the sea. Basaltic hills rise in the midst of a country, in which porphyry, with base of green stone, predominates. Their summits are crowned with oaks, always in verdure, and the foliage of laurels and olives, intermingled with dwarf fan palms. This beautiful vegetation forms a singular contrast with the arid plain, which has been laid waste by volcanic fire.

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 thirteen 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 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 a 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, 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° in the crevices that emitted an aqueous vapour. Each little cone is a chimney, from which a thick smoke rises to the height of eleven or sixteen 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 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 Auvergne, is the dark 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 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 thermometor rose to 43°. 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 uninhabitable for several years, and even to a considerable distance from the ground raised up, on account of the excessive heat.

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 compli cated 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 after 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.

GOLD AND DIAMOND MINES.

MINES OF VILLA RICA, &c.

BRAZIL.

(From Mawe's Rio Janeiro)

THE mountain on which Villa Rica stands, appeared to Mr. Mawe to be from eight to nine miles across, and was chiefly composed of slate. This mountain was once excessively rich in gold; and for some time many private adventurers collected great quantities of it. This they appropriated to their own use, without paying the royal claim of one-fifth part of the produce. Since the year 1711, however, proper persons have been stationed here, for the regulation of the mines, and now all the gold that is obtained is delivered to certain officers that are appointed by the government to receive it. These take one-fifth of the whole weight for the prince regent; and the remaining four parts are purified, melted into pieces called ingots, then assayed, marked according to their value, and delivered to the owners, with a certificate to render them current

About the year 1713 the quantity of gold obtained here was so considerable, that the royal fifth amounted to nearly half a million sterling per annum. The mountain became pierced like a honeycomb, for the miners penetrated every soft part they could find, and conveyed the cascalhao or substance dug out, to a convenient place to be washed. In rainy weather the torrents of water running down the sides of the mountain carried away much earthy matter, which contained small particles of gold, and deposited them in the ground near the base. When the waters abated, this rich deposit gave employment to great numbers of the people, who took it away and washed it at their convenience. Between the years

1730 and 1750 the mines were in the height of their prosperity. From this time they gradually became less productive, and, when Mr. Mawe was here, Villa Rica scarcely retained even a shadow of its former importance. During his residence at this place, Mr. Mawe paid frequent visits to the mint; and he was permitted to witness every process that was performed there. In the smelting house he saw eight or ten small blast furnaces, which in form resembled so many blacksmith's hearths. The fuel used was charcoal. When a quantity of gold dust was brought by any person, it was immediately melted, purified, cast, and stamped. So that Mr. Mawe has seen men deliver their gold dust, and receive it in a form ready for use or circulation in less than an hour.

At a place where gold was washed, about six leagues from Villa do Principe, Mr. Mawe says, that a lump of gold was found of several pounds weight; and from the same place he obtained many curious and chrystallized pieces, and some specimens which weighed more than two ounces each.

On the arrival of the Travellers at Tejuco, they took up their abode in the principal inn of the place, a house which contained some neat rooms, and afforded tolerable accommodations. This town is built on the side of a mountain, and in a narrow valley which runs along its bottom

The governor of the diamond district, having learned that Mr. Mawe was expected, came to Tejuco to meet him, and on the morning of Monday the 18th of Sept. they set out together on a journey to the great diamond works, at Mondanga, on the banks of the river Jigitonhonha. At these works about a thousand negroes were at this time employed.

The method of washing for diamonds is as follows:a shed consisting of upright posts, and a roof thatched with long grass is erected in the form of a parallelogram twenty-five or thirty yards long, and about fifteeen yards wide Down the middle of the area of this shed a current of water is conveyed through a canal covered with strong planks, on which the cascalhao is laid, two or three feet thick On the other side of the area is a flooring of planks, embedded in clay, four or five yards wide, ex