ances in this cavern, it seems to have been in former times the habitation of man, perhaps the bandit's home. 2. Cave near the village of Hutton in the Mendip Hills. This Kent's Cave, near Torquay. is a series of cavernous chambers found by the labourers in working for ochre, which occurs in fissures of the mountain limestone. In the first chamber, about twenty feet square and four high, a large stalactite depends from the roof in the centre, and beneath a stalagmite rises from the floor, nearly touching it. The bones from this cavern are those of the elephant, horse, ox, deer, bear, and hog. 3. Cave at Balleye, near Wirksworth. Bones and molar teeth of the elephant were discovered here in a cavity of mountain limestone by the lead miners, mentioned in the following record of a workman: "In sinking for lead at Baulee, within two miles of Wirksworth, A. D. 1663, they came to an open place as large as a church, and found a skeleton reclining against the side, so large that his brain-pan would have held two strike of corn, and so big that they could not get it up without breaking it. My grandfather having a share in the said mine, they sent him a tooth, weighing four pounds three ounces.-George Mower." Some of these remains are still preserved. 4. Dream Cave, near Wirksworth. This was likewise discovered by the miners in pursuing a vein of lead. After sinking about sixty feet through solid mountain limestone, they came to a large cavern filled with argillaceous earth and stony fragments. Here were found the remains of a rhinoceros, in a high state of preservation. They belonged apparently to the same individual, and formed probably an entire skeleton, though several parts were wanting, having been separated from the rest through the subsidence of the mass in which they were imbedded into an underlying hollow, owing to the workmen disturbing the site. Bones of deer and fragments of horns were found in the same spot, all of which are now deposited in the Oxford Museum. 5. Cave on Derdham Down, near Clifton; a fissure which contained fragments of stone and stalagmite, with bones incrusted with stalactitic matter, among which was a fossil joint of the horse. 6. Caves at Oreston, near Plymouth. Several caverns were discovered in removing materials for the construction of the Breakwater from a hill of transition limestone. They contained bones belonging to a species of rhinoceros, the tiger, hyæna, horse, ox, wolf, and deer. 7. Cave of Crawley Rocks, near Swansea. This cavity was accidentally intersected in working a quarry. It has now been entirely cut away. Various parts of the elephant, rhinoceros, hyæna, ox, and stag were found in it. 8. Caves of Paviland. Two cavities occur in a lofty cliff of limestone facing the sea on the coast of Glamorganshire, which the waves reach in considerable storms. The remains of an immense number of animals of extinct species have been found in them. It is clear from these facts, that anciently, as Dr. Buckland remarks, "extinct species of hyæna, tiger, bear, elephant, rhinoceros, and hippopotamus, no less than the wolves, foxes, horses, oxen, deer, and other animals which are not distinguishable from existing species, had established themselves from one extremity of England to the other-from the caves of Yorkshire to those of Plymouth and Glamorganshire - whilst the diluvial gravel beds of Warwickshire, Oxford, and London, show that they were not wanting also in the more central parts of the country; and M. Cuvier has established, on evidence of a similar nature, the probability of their having been spread in equal abundance over the continent of Europe. But it by no means follows, from the certainty of the bones having been dragged by beasts of prey into the small cavern at Kirkdale, that those of similar animals must have been introduced in all other cases in the same manner; for, as all these animals were the antediluvian inhabitants of the countries in which the caves occur, it is possible that some may have retired into them to die; others have fallen into the fissures by accident, and there perished; and others have been washed in by the diluvial waters. By some one or more of these latter hypotheses, we may explain those cases in which the bones are few in number and not gnawed, the caverns large, and the fissures extending upwards to the surface; but where they bear marks of having been lacerated by beasts of prey, and where the cavern is small, and the number of bones and teeth so great and so disproportionate to each other as in the cave at Kirkdale, the only adequate explanation is, that they were collected by the agency of wild beasts." In Germany the zoolithic caverns are much more numerous and important than in England. There is a remarkable example on the north-east border of the Hartz Mountains, called Bauman's Höhle, after an unfortunate miner who, in the year 1670, ventured into it alone in search of ore; and, after having wandered three days and nights in its solitude and darkness, at length found his way out, but in such a state of exhaustion that he died almost immediately. It is a suite of natural chambers in a bed of transition limestone, the floor of which is composed of a thick crust of stalagmite, beneath which lies an accumulation of several feet of mud mixed with bones and pebbles. But the caves of Franconia are by far the richest and most beautiful of this class. They lie on the north-east extremity of the chain of the Jura between Nuremburg and Baireuth, in the valley of the Wiesent, a tributary stream of the valley of the Maine. The most important is the Cave of Gailenreuth, situated in a perpendicular rock, its mouth being upwards of three hundred feet above the bed of the river, consisting of an aperture seven feet high and twelve broad. An open fissure in the rock extends from the cave to the table-land above, as shown in the illustration. The floor consists of stalagmite lying over a bed of slime which contains the animal remains. The cave has two chief chambers, the roof of which is abundantly hung with stalactites. From the first to the second chamber the visitor descends by a ladder, as represented in the section, which exhibits the breccia of bones, pebbles, and loam, and the artificial extension of the cavern by the removal of it. Gailenreuth. Almost all the bones belong to the bear of the caverns, and are admirably preserved. Those of a species of cat, resembling the American jaguar, have also been discovered, and those of the hyæna; but the latter are of rare occurrence. In conformity with the habits of the bear, the remains of prey, dragged in, are almost entirely wanting. There are two neighbouring caverns of the same class; those of Zahnloch (teeth-hole) and Kühloch. The latter is supposed to contain animal matter equal to at least 2500 individuals of the cavern bear; and allowing an annual mortality of 2, it follows that here we have the history of a thousand years; for probably these animals retired to the solitude of this spot upon the approach of death, as is the well-known custom of many creatures. The bone caverns in our own records of human history the rhinoceros, elephant, and hyæna, now, and for ages past, exclusively confined to more southern latitudes. There is another class of caverns remarkable for the development of irrespirable gas, which often renders the access to them dangerous. They are of two kinds; those in which the gas is produced by the surrounding rocks, and those in which it pro ceeds from the interior of the earth. The first class are principally caves of gypsum. The gypsum is not, however, the cause of the phenomenon, the component parts of which are not susceptible of any decomposition from the air. There is commonly fœtid limestone intimately mixed up with it, which forms connected wavy stripes, and even single beds of considerable thickness. This earthy limestone, which is penetrated with bitumen, and often very clayey in its composition, has the property of giving out all its carburetted hydrogen in the air; and in every case where caves exist in it, its presence, on account of its connection with gas, is offensive and much dreaded. In the limestone caves of the sandstone formations, on the contrary, there commonly prevails a very pure air, possibly because they are filled with mouldering animal remains. The development of irrespirable gases from the interior of the earth, which, penetrating through fissures, collect in caves, is a constant result of volcanic activity. The chemical processes continually going on in volcanic regions must produce the liberation of great quantities of gas, which are connected with the world above by these chimneys of the perpetual forge. Caverns of this nature occur therefore only in the neighbourhood of volcanoes, or at points where volcanic processes may be supposed to be going on beneath. The gases so developed are almost entirely the carbonic and sulphuric acids. Among the most important of the grottos which give out carbonic acid, there is the Grotto del Cane at Naples, in the neighbourhood of the Lago d'Agnano, near Pozzuoli. It was known to the ancients, and is mentioned by Pliny, who refers to it as one of a class of excavations called, in his time, "Charon's ditches." Its size is very unimportant; ten feet deep, four feet broad, and nine feet high. The carbonic acid collects itself on the soil in a bed of about six inches deep; and, on account of its specific gravity, does not mingle with the atmospheric air. Its actual height may be clearly ascertained by lighting some candles, which, when they reach its surface, are extinguished at once. Small animals falling in are speedily suffocated; and it takes its name from the dogs which are placed in it by way of experiment. The cave and its neighbourhood appear to have undergone some considerable changes; for, from Pliny's reference to the mephitic gas, it would seem to have been fatal to human life, which is not possible now, owing to the small height of the stratum, unless an individual threw himself upon the surface of the floor. According to some ancient accounts, bubbles were constant upon the lake Agnano close by, occasioned by the escape of gas, of which there is no appearance now; so that the quantity of deadly air exhaled has been much reduced, if dependence may be placed upon these authorities. A similar instance, on a much larger scale, is seen in the crater of the extinct volcano of St. Leger, or of Neyruc in the south of France, on the banks of the Ardêche, amid the great number of volcanic remains of that region. This crater exhibits a cultivated, and in part inhabited, district, which is surrounded like an amphitheatre by the ancient walls of volcanic débris. Its soil is one vast sieve for the ascent of carbonic acid. Perforations have been made in it to facilitate the emission of the gas, and guide it from the fields, to which its contact is very injurious. The height of the bed of gas, over the ground of these holes, has been found to be, in the most favourable circumstances, about one foot and a half. Changes of weather have the most important influence on it; and in violent rains the whole mass of gas is absorbed. The quantity of this gas, which issues from the soil of the whole neighbourhood, has a very striking influence on the health of the inhabitants who work in these fields; and if the proprietors do not yearly clear out these perforations, their harvest is lost by means of the poisonous vapours. Another example occurs near Pyrmont, where there is a cavern of mephitic gas, named Dunsthohle, which exhibits the same phenomena as the dog grotto near Naples; and of a kindred kind is the extraordinary valley in the island of Java, called by the natives Guwo-upas, poisoned valley, which is without vegetation, and strewed with the skeletons of human beings, quadrupeds, and birds, being generally half-filled with a noxious gas which destroys life in a few minutes. In addition to the cavities which are the handiwork of nature, immense subterranean spaces have been excavated by the labour of man, chiefly in the limestone, coal, and salt formations, to obtain the products which are essential to the arts of life. At certain points and limits of the South Staffordshire "Coal Basin," the limestone stratification is abruptly exalted from its normal position, which is several hundred feet below the regular surface, and forms a striking object in scenery, and a picturesque mountain boundary, to the district of towns, hamlets, and villages, in which the usual mining operations for coal and iron stone are pursued. It is worked to procure a valuable flux for the iron furnaces -cement for building-and a manure for agricultural purposes. Dudley Castle Hill is a bold and rugged prominence, where the quarries were primarily worked. The excavations at first were open to the light, commencing from the protruding ridges and peaks, and forming in time a deep hollow or ravine. Clearing the rock as far as was convenient, the rapid inclination of the stratum was followed, and the work was then continued at a much lower level, in the form of gloomy tunnels, afterwards threaded by dark and dangerous canals, necessary for the conveyance of the product of the perforated region. At the lower part of the castle grounds, and not far distant from the Eastern Lodge, is the descent to one of the great caverns, answering to our illustration. By a few uncertain slippery steps the visitor arrives at the moist crumbled floor of a wondrous avenue of rock works. Indistinctly, and at an inferior plane, glimmer the dull waters of the canal, the line of which is only broken in part by a covered way, to re-appear in the onward distance of the hazy mine. As the strata are sometimes at an angle of eighty degrees, sometimes less, the enormous broad-footed pillars of material left to support the irregular roof, answer to such inclination, and are perpendicular to it, presenting a wild and singular appearance. The force and sublimity of this scenery by torchlight are most interesting, and the frowning boundaries of the spacious crypts, the pillars, and the rude chambers, remind one distinctly of the mazes of the Memphic tombs. Proceeding to the left, Q |