haps a small cave. It was impossible to penetrate into this cavity; but it may be presumed that the tremendous noise was occasioned by a broken rock, driven by the violent impetuosity of the surge against its sides. By the boiling motion of the water, however, in the same place, it is evident that there are several other small passages, through which it issues, after rushing into the principal aperture in a mass. It is therefore not impossible, when the sea is not sufficiently agitated to put the imprisoned rock in motion, that the air, strongly compressed by the weight of the water, which is in incessant fluctuation, should, on rushing out by the small lateral passages, produce a particularly strange sound. It might then be truly regarded as an organ created by the hand of nature; and this circumstance would fully explain why the ancient and real name of this cave, in the Erse language, is, The Melodious Cave." Sir Joseph Banks, in the description which he has given us of the cave of Staffa, says, that "between the angles a yellow stalagmitic matter has exuded, which seemed to define the angles precisely." That is true; but the learned naturalist has not told us the nature of this yellowish matter. Mr. Troil mentions it also: he says, that the "colour of the columns is a dark gray, but that the joints are filled with a quartzose stalactites, which distinctly marks the separation of the columns, and which, by the variety of its tints, has the most agreeable effect on the eye. On breaking off several pieces of it, which it is not very easy to do, owing to the height of the vault, I found that it was nothing but a calcareous matter, coloured by the decomposition of the iron of the lava, and intermixed with a little argillaceous earth. This stalactites has also very little adhesion, and is, in general, of an earthy nature. In several of the prisms I found some globules of zeolites, but in very small quantity. I also broke off from between two prisms, which were so apart as to admit of introducing my hand, an incrustation in which the white and transparent zeolites was formed into very perfect small cubical crystals, several of which were coloured red by the ferrugi nous lime arising from the decomposition of the lava. But I must repeat, that zeolites is very rare in this cave, and having myself broken off all the specimens that I was able to see, I doubt whether those who may visit the place after me will find any quantity of it." Dimensions of the Cave of Fingal.-Breadth of the entrance, taken at the mouth and at the level of the sea, thirty-five feet; height, from the level of the sea to the pitch of the arch, fifty-six feet; depth of the sea, opposite to the entrance, and twelve feet distant from it, at noon of the 27th of September, fifteen feet; thickness of the roof, measured from the pitch of the arch without to its highest part, twenty feet; interior length of the cave from the entrance to the extremity, one hundred and forty feet; height of the tallest columns on the right side of the entrance, forty-five feet; depth of the sea in the interior part of the cave, ten feet nine inches, in some places eight feet, and towards the bottom somewhat less CAVE NEAR MEXICO. A traveller of credit gives us an account, in the Philosophical Transactions, of a remarkable cave, some leagues to the north-west of Mexico, gilded all over with a sort of leaf-gold, which had deluded many Spaniards by its promising colour, but they could never reduce it into a body, either by quicksilver or fusion. This traveller went thither one morning with an Indian for his guide, and found its situation was pretty high, and in a place very proper for the generation of metals. As he entered into it, the light of the candle soon discovered on all sides, but especially over his head, a glittering canopy of these mineral leaves, at which he greedily snatching, there fell down a great lump of sand, that not only put out his candle, but almost blinded him, and calling aloud to his Indian, who stood at the entrance of the cave, as being afraid of spirits and hobgoblins, it occasioned such thundering and redoubled echoes, that the poor fellow, imagining he had been wrestling with some infernal ghosts, soon quitted his station, and thereby left a free passage for some rays of light to enter, and serve him for a better guide. The traveller's sight was somewhat affected by the corrosive acrimony of the mineral dust; but having relighted his candle, he proceeded in the cave, heaped together a quantity of the mineral mixed with sand, and scraped off from the surface of the earth some of the glittering leaves, none of which exceeded the breadth of a man's nail, but with the least touch were divided into many lesser spangles, and with a little rubbing they left his hand gilded all over. We must not neglect to notice THE NITRE CAVES OF MISSOURI." On the banks of the Merrimack and the Gasconade are found numerous caves, which yield an earth impregnated largely with nitre, which is procured from it by lixiviation. On the head of Current's river are also found several caves from which nitre is procured, the principal of which is Ashley's cave, or Cave Creek, about eighty miles south-west of Potosi. This is one of those stupendous and extensive caverns, that cannot be viewed without exciting our wonder and astonishment, which is increased by beholding those complete works for the manufacture of nitre, situated in its interior. "The native nitrate of potash is found in beautiful white crystals, investing the fissures of the limestone rock which forms the walls of this cave; and several of those in its vicinity exhibit the same phenomenon."-Schoolcroft, on the Lead Mines of Missouri. OKEY HOLE. This is a famous natural cavern of England, on the south side of Mendip hills. The entrance is in the fal of those hills, which is beset all about with rocks, and there is near it a precipitate descent of twelve fathoms deep, at the bottom of which there continually issues from the rocks. a considerable current of water. The naked rocks above the entrance are about thirty fathoms high, and the whole ascent of the hill above, which is very steep, is about a mile. The entrance into this vault is at first upon a level, but advancing farther, the way is rocky and uneven, sometimes ascending, and sometimes descending. The roof of this cavern, in the highest part, is about eight fathoms from the ground, but in many places it is so low, that one must stoop to get along. The breadth is not less various than the height, for in some places it is five or six fathoms wide, and in others not more than one or two. It is in length about two hundred yards. At the farthest part of the cavern there is a stream of water, large enough to drive a mill, which passes all along one side of the cavern, and at length slides down about six or eight fathoms among the rocks, and, finding its way through the clefts, falls into the valley beneath. The river within the cavern is well stored with eels, and has some trouts. In dry summers, a great number of trogs are seen all along this cavern, even to the farthest part of it; and on the roof are vast numbers of bats. From Okey Hole we proceed to BORROWDALE,—which is a most romantic valley among the Derwent-Water Fells, in the county of Cumberland. These fells or hills are some of the loftiest in England, and it is in one of them that the black lead, or wadd, is found, from which all parts of the world are supplied. The mines are opened once in seven years, and when a sufficient quantity of this valuable and singular mineral is taken out, they are carefully closed again. In travelling among these mountains, the idea that presents itself to the astonished spectator, is that of the earth having been agitated like the ocean in a storm; the hills appear like waves, one behind another, and were it not for the abrupt and sudden scarps, and the immense masses of rugged rocks, that give the idea of fixedness and stability, the fancy might be bewildered so far as to imagine they were in a state of undulation, and ready to mingle with each other. THE NEEDLe's eye. Borrowdale is watered by the clearest brooks, which, precipitated from the hills, form many beautiful waterfalls, and then meet together in the dale in one large stream, and pass out of it under the name of Borrowdale Beck, when they spread out into an extensive lake, forming many beautiful islands; the lake is called Derwent-water, or Keswick Lake. Borrowdale is four miles from Keswick, in passing from which, the traveller has the lake on his left hand, and stupendous rocky precipices on the other; with huge stones, or rugged masses of rock, which have tumbled from above, perhaps rent from the mountain by the expansion of the water in its crevices or fissures, which, congealing into ice, occasions the scattered fragments that lie in his way. As he approaches the dale, he sees the shelves, or ledges of the rocks, covered with herbage, shrubs, and trees, and villages and farms rise in his view; the larger cattle are seen feeding in the lower grounds, and the sheep in very large flocks upon the mountains. We shall close this division with an account of THE NEEDLE'S EYE.-This name is given to a subterraneous passage on the coast of Banffshire, one hundred and fifty yards long from sea to sea, but through which a man can with difficulty creep. At the north end of it is a cave, twenty feet high, thirty broad, and one hundred and fifty long, containing a space of ninety thousand cubic feet. The whole is supported by immense columns of rocks, is exceedingly grand, and has a surprisingly fine effect on the spectator, after creep ing through the narrow passage. CHAP. XLIII. CURIOSITIES RESPECTING MINES. Diamond Mine in the Brazils-Mines of Peru-Volcanic Eruptions of Mud and Salt-Pitch Wells-Visit to a CoalPit. Through dark retreats pursue the winding ore, Search Nature's depths, and view her boundless store; How metals first were fram'd, and whence they spring Yalden. Description of a DIAMOND MINE on the river Tigitonhonha, in the Brazilian territory; by Mr. Mawe. "I could not (says the writer) resist the favourable opportunity now offered me of gratifying the curiosity which had so long occupied my mind, by visiting the diamond mines, in company with the principal officer in the administration of them, who was therefore qualified to furnish me with the amplest information. A fine horse was waiting for me at the door, and I rode up to the house of the governor, who introduced me to his amiable lady, daughters, and family, with whom I had the honour to take breakfast. Several officers of the diamond establishment arrived on horseback to accompany us, their presence being required on this occasion. "Having arrived at the place, I remained here five days, during which I was occupied in viewing and examining various parts of the works, of which I shall here attempt to give a general description. "The river Tigitonhonha is formed by a number of streams, and is as wide as the Thames at Windsor, and in general from three to nine feet deep. The part now in working is a curve or elbow, from which the current is diverted into a canal cut across the tongue of land round which it winds, the river |