This country suffers many inconveniences from a want of water, and particularly of navigable rivers. The Rio del Norte and the Rio Colorado are almost the only _rivers_ of any importance. The _lakes_ with which Mexico abounds, are merely the remains of immense basins of water, which appear to have formerly existed on the high and extensive plains of the Cordilleras. The largest of these, the _Lake of Chapala_, contains nearly one hundred and sixty square leagues, and is about twice as large as the lake of Constance. A great portion of high land, in the interior of New Spain, is destitute of vegetation; and some of the loftiest summits are clad with perpetual snow. This country is not so much disturbed by earthquakes as several parts of South America; for, in the whole of New Spain there are only five _volcanos_; Orizaba, Popocatepetl, Tuxtla, Jorullo, and Colima. The _volcano of Jorullo_, in the province of Valladolid, was formed during the night of the 29th of September, 1759. The great catastrophe, in which this mountain rose from the earth, and by which a considerable space of ground changed its appearance, is, perhaps, one of the most extraordinary physical revolutions in the history of the earth. Geology points out parts of the ocean, where, at recent periods, near the Azores, in the Egean Sea, and to the south of Iceland, small volcanic islands have arisen above the surface of the water; but it gives no example of the formation, amidst a thousand small burning cones, of a mountain of scoria, near seventeen hundred feet in height, above the adjoining plain. Till the middle of the year 1759, fields cultivated with sugar-canes and indigo occupied the extent of ground between the two brooks called Cultamba and San Pedro. In the month of June, a subterraneous noise was heard. Hollow sounds of most alarming description, were accompanied by frequent earthquakes, which succeeded one another for fifty or sixty days, to the great consternation of the inhabitants. From the beginning of September every thing seemed to announce the complete re-establishment of tranquillity; when, in the night between the 28th and 29th, the subterraneous noises recommenced. The affrighted Indians fled to the mountains; and a tract of ground, from three to four square miles in extent, which goes by the name of _Malpays_, rose up in the shape of a bladder. The bounds of this convulsion are still distinguishable in the fractured strata. The Malpays, near its edges, is only about forty feet above the old level of the plain; but the convexity of the ground thus thrown up, increases progressively, towards the centre, to an elevation of more than five hundred and twenty feet.