that in the early ages of the world a universal deluge overspread the whole frame of the globe. On no other supposition can we account for those traces of violent destruction or agitation by water, which are to be met with in every country, or the situation of those marine productions which we find at the tops of the highest mountains. The most ancient mountains, or those forming the basis of all the others, are entirely destitute of organic remains and petrifactions, and in all probability existed before the universal deluge. They consist of granite, gneiss, mica slate, primitive limestone or dolomite, serpentine, primitive clayslate, syenite, porphyry, and quartz. The great bulk of the highest or primitive mountains is composed of granite,-a mixture of felspar, quartz, and mica, disposed in distinct granular concretions of various magnitudes and forms. Granite not only forms the most elevated masses at the surface of the globe, but descends into the bowels of the earth, where it is supposed by some geologists to form a vast connected vaulting, supporting all the other masses of matter which compose the crust of the globe. It is seldom found in the advanced chains.

Transition Rocks.] The primitive rocks are succeeded by the transition rocks, which do not exhibit any organic remains, but occasionally contain petrifactions. To this class of rocks belong clay-slate, floetzlimestone, greenstone, pyrite slate, grey wacke, and transition chalk. The inclination of transition stratas is always regulated by that of the granite strata on which they rest.

Floetz Rocks.] The distinction between primitive and floetz rocks lies partly in their external appearance, the former being high and steep, the latter low and flat,-partly in their internal constitution,-and partly in the matters of which they are composed. The elder floetz rocks are of higher elevation than the others, and consist of sandstone, breccia, coal, and slate-clay, on which the finest impressions of antediluvian plants are perceived. The younger floetz mountains are usually situated at a greater distance from the primitive mountains, and flatten gradually as they recede from the main chain till they sink into the plain. Their stratas exhibit a species of sand-breccia of a very regular form, a bituminous marl-slate with remains of fishes, and many varieties of gypsum, and sandstone. The upper stratas exhibit gypsum and chalk, intermingled with flints and petrifactions. A remarkable feature in the floetz formations is the transverse veins and galleries which in some instances intersect the stratas. These are sometimes empty, and sometimes filled with fossil substances, and lead, copper, and cobalt ores. In general, the floetz mountains contain mines of copper-slate, alum, vitriol-slate, calamine, naphtha, coal, rock-salt, and salt and warm springs.

Alluvial Soil.] From the above three classes of formations, we must distinguish the very latest which have been produced from partial motions of the fresh waters at the surface of the globe: as, for instance, on the shores and mouths of the Mississippi, the Amazon river, and the Nile; or by the gradual depositation from subsiding lakes, of which a singular instance occurs in the parallel roads of Glen Roy in our own country. We also find instances of alluvial deposits, either from the debris of the cliffs, or from the earthy substances kept in suspension by

'From this observation we must except the Chimborazo mountain, which, according to Humboldt, consists of an enormous mass of porphyry reposing upon granite.

the waters of the ocean, on the shores of the Baltic, the Mes and the German Ocean. In these sandy and clayey deposits of various large animals are frequently discovered in a state tion, or strongly impregnated with bitumen. Floetz, chalk, stone, occur in alluvium; also pit-coal, and argillaceous clay. formations are often found covered with insulated blocks of gr presence of which cannot be easily accounted for.

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Volcanic Rocks.] Besides these masses of stone and soil f precipitation, we find a class of rocks and earths at the surfa globe which have been produced by the action of subterrane Although there are still several active volcanoes in different re the globe, their number is small when compared with that of th guished volcanoes, whose activity at some distant and unknowi is proved by indubitable evidence. Thus, in Germany, there a of about fifty extinguished volcanoes in one small tract of extending from Göttingen to the Rhine. In Auvergne, in Fra find a line of volcanoes, which appear to have been extinguis Highest ascertain above 2000 years, stretching 60 leagues in length. Volcanoes arantz grow class of mountains peculiar to any particular district of the earth rise in the midst of primitive, or of floetz ridges, as well as in plair also break out from unfathomable depths below the sea. Shaw, how states, that in the volcanic districts a series of points seemingly contab may be traced. The whole granitic chain which borders the Pac crowned by volcanoes, beginning at the Straits of Magellan, with Andes, which in Chili have sixteen burning craters. Those of Per very numerous and terrible, as are those of the isthmus of Mexico California. The littoral chain to Alashka offers several volcanoes, in activity. Others are found in that semicircular chain of is between the continents, terminating near Kamschatka, in which peni are five active volcanoes, besides many extinct craters, which reac Daouria. South of Kamschatka, the ignivomous chain traces the K islands, Jesso, and Japan. A series of volcanic islets joins on to Marianne Isles, which have nine active volcanoes, and thence runs thro Polynesia. Another branch runs south, by Lieoukiou, Formosa, Philippines, Indian Archipelago, and Australasia, to New Zeala where we perceive unequivocal signs of subterranean fires. Several ran cations go off to the Indian Sea. There are volcanic appearances in Himalayah mountains. In the Mauritius is an active volcano; the Is of France and Madagascar, St. Paul, and Amsterdam, are covered w lavas, ashes, and scoriæ; the mineral waters and confused mountai of the Cape of Good Hope indicate subterranean fires. On the coa of America, Guadaloupe, Dominica, and Trinidad have active crater Fires burst forth occasionally in the caverns of Lemnos, Milo, an Santorin. The Ionian Isles, in the Adriatic, are volcanic; and ne islands have been formed by volcanic explosions in the Grecian Archipe lago within the 18th century. Sicily has its Etna, Naples its Vesuvius and Strombolo lightens up the islands of Lipari. All Italy offers vess P tiges of ancient volcanoes, in the Appenines; on the coasts of Provenc are the extinct craters of Olioules and Evenos; there is one on the Alpst of Dauphiny; and in Spain volcanic solfaterras, lavas, and puzzolanas are Fo found in the environs of Burgos. All Upper Germany, between the Alps and Krapacks, indicates ancient volcanoes, especially in Bohemia, Hesse, Lusatia, Hungary, and Silesia. Mount Atlas rests on volcanic ground,

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and also the islands of St. Helena and Assumption, composed of lavas and ashes; the Cape Verd Islands, of which Fuego always throws out flames; the Canaries, whose Peak of Teneriffe is a higher volcano than Etna; the Azores, incessantly disordered by submarine fires; the British Isles, with Ireland, famed for its Giants' Causeway; the Hebrides, the Feroe Islands; and, finally, Iceland, which terminates this long chain by Mount Heckla, a focus more active than Vesuvius. When these fires were kindled, by what sort of fuel they are still maintained,—at what depths below the surface of the earth they are placed,-whether they have a mutual connexion,-and how long they may continue to burn, are questions which do not admit an easy decision. The greater number of volcanoes rise in the form of a cone. Their mouth, or crater, has generally the shape of a cup, or an inverted funnel; in some instances, however, the lava breaks out from the sides. When the fires find no issue, they produce earthquakes. When Vesuvius throws off its inflammable contents by moderate and regular eruptions, the inhabitants of Naples stand in little dread of the occurrence of an earthquake, which is always most violent after a period of long repose. The extent of volcanic influence is amazing. The great eruption of Tomboroo, in one of the islands of the Indian Archipelago, was felt throughout a circular space of 2000 miles in diameter. It seems to be a general rule, that the greater the mass and the elevation of the mountain, the less frequent, but more tremendous are the eruptions. Volcanic productions have been arranged in six classes: viz. 1st, Opaque lavas, including basalt, remarkable for its regular prismatic forms; 2d, Porous lavas; 3d, Vitrified lavas, affording a real opaque glass of a dark colour, known by the name of Iceland agate; 4th, Pumice-stone, a well-known mineral, specifically lighter than water; 5th, Volcanic ashes, of a clear gray colour, which, in the form of powder, are called puzzolana, and when conglomerated together, tufa, or trass; 6th, Volcanic breccia, a species of lava containing a variety of foreign substances. When these volcanic products are reduced to dust by the action of the atmosphere, they produce a highly fertile soil. Some species of lava are solid, and can be wrought into different fancy articles, such as snuff-boxes; the common lava is made use of in Italy for paving the streets, and in building. Sulphur, and a variety of salts, are produced on the sides of volcanic craters; and in some instances immense quantities of boiling water are ejected by volcanoes.

Caverns.] The caverns which are so frequently found in mountains, particularly in limestone formations, have been formed by the action of water, by earthquakes,-by the sudden sinking of portions of the soil, or by subterranean fires. They either consist of a range of galleries, or of one or more grottoes, lying behind or above each other. The depth of some caverns exceeds 1000 feet; and some, such as the Nicojack cave in the territory of the Cherokees, extend several miles in length. The stalactite columns and singular concretions, formed by the dripping of water from their sides and roofs, frequently give singular beauty to their interior, and when illuminated by torch-light, produce a magnificent and dazzling spectacle. From some caverns there is a continual rush of wind; others emit peculiar vapours; in some clear springs well up; and others are traversed by streams of water. Many curious petrifactions and large accumulations of the bones and teeth of various known and unknown animals have been found in caverns, where they must have been deposited at some very distant period. Among the most remarkable caverns are