philosophers seem in great measure to coincide. Fourcroy observed, forty years ago, that "it could not be denied, that the strata of calcareous matter, which constitute, as it were, the bark or external covering of our globe, in a great part of its extent, are owing to the remains of the skeletons of sea animals, more or less broken down by the waters; that these beds have been deposited at the bottom of the sea; that such is likewise the origin of bitumen, especially seacoal; immense masses of chalk, deposited on its bottom, absorb or fix the waters, or convert into a solid substance part of the liquid which fills its vast basins." Supplement to Chemistry, p. 263. Such are the conclusions of philosophical investigation; and the discoveries of all our circumnavigators fully corroborate these decisions as to formation. Revelation in part accounts for the removal of these stupendous masses; though, probably, unrecorded concussions since the great subversion of our planet have, in remote periods, effected many of the removals of these deposits. We find the basement of many of the South Sea islands, some of which are twenty miles long, formed of this matter. Captain Flinders, in the gulf of Carpentaria, held his course by the sides of lime stone reefs, five hundred miles in extent, and three hundred fathom deep; and still more recently captain King, seven hundred miles, almost a continent, of rock, increasing, and visibly forming :-all drawn from the waters of the ocean by a minute creature, that wonderful agent in the hands of Providence, the coral insect. This brief account of the origin of calcareous rocks was, perhaps, necessary before mentioning an extraordinary fact, that, after the lapse of so vast a portion of time since the basement of the mighty deep was heaved on high, existing proofs of this event should remain in our obscure village. The limestone rocks here are differently composed, but are principally of four kinds—a pale gray, hard and compact; a pale cream-coloured, fine grained and sonorous: these form the upper stratum of stone on our down, a recent deposit, or more probably a mass heaved up from its original station. The whole of this mass, running nearly half a mile long, is obviously of animal formation, a coral rock; a compounded body of minute cylindrical columns, the cells of the animals which constructed the material; the mouths of which are all manifest by a magnifier. The stop in the progress of the work is even : visible; soft, stony matter having arisen from some of the tubes, and become indurated there in a convex form; in others the creatures have perished, but their forms or moulds remain, though obscure, yet sufficiently perfect to manifest the fact these tubes, by exposure to the air for any length of time, have the internal or softer parts decomposed, and the stone becomes cellular. A. (Plate 2, Fig. 1) represents an enlarged fragment of the down limestone, with the mouths of the cells; B. C. D. are the appearance of some of them, with the forms of the insect which constructed them; E. represents the stony matter by which the work is continued fixed at the mouth of the cell; Fig. 2. the same when decomposed, the animal matter having quite perished in some cases, and partially in others; Fig. 3. enlarged. This stone burns to a fine white lime, and is very free from impurities, containing, in a hun * I have called this alumine, stained with oxide of iron; but it seems more like vegetable or animal remains, adhering to the filter like a fine peaty deposit, and is lost in combustion. Another quarry presents, likewise, unquestionable evidence of an animal origin, veins of it being composed of shattered parts of shells, and marine substances, greatly consumed and imperfect, embedded in a coarse, gray, sparry compound; an ocean deposit, not à fabrication; and consequently has more impurities in its substance than that of insect formation; it contains about These two specimens so clearly prove, that the original materials of their substance were derived from the deep, that no further arguments need be advanced to support this fact as to our limestone. The former is, perhaps, the mountain limestone of Werner; the latter a variety of dolomite. Our other quarries, as well as the lower strata of the above, present no such indications of animal formation, and they are probably sediment arising from a minute division of shelly bodies, now indurated by time and superincumbent pressure, and become a coarse-grained marble. Our limestone thus appearing not to be contaminated with any great portion of magnesian earth, it may be used for all agricultural purposes with advantage. Many detached blocks of limestone are found about us, having broken shelly remains, and the joints of the encrinite, greatly mutilated, embedded in them. Irregularly wandering near the lime-ridge is a vein of impure sandy soil, covering a coarse-grained silicious stone; sand agglutinated, and coloured by oxide of iron, resisting heat, and used in the construction of our lime-kilns: the labourers call it "fire stone." We occasionally, though sparingly, find,in a few places on our downs, nodules of lead ore, which induced persons in years past to seek for mineral riches; but the trial being soon abandoned, the result, I suppose, afforded no reasonable ground for success. We likewise find thin veins of carbonate of strontian, but make no use of it; nor is it noted by us different from common rubbish ; nor do I know any purpose to which it is peculiarly applicable, but in pyrotechnics. Spirit of wine, in which nitrate of strontian has been mixed, will burn with a beautiful bright red flame; barytes, which approaches near to strontian, affords a fine green; nitrates of both, compounded with other matters, are used in theatrical representations. Strontian exists in many places, and plentifully; some future wants or experi |