deposited at the bottom of the sea, 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 limestone reefs, five hundred miles in extent, with a depth irregular and uncertain; 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-colored, 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. This stone burns to a fine white lime, and is very free from impurities, containing in a hundred parts— Carbonate of lime 88 Magnesia 8 Silex 1 Alumine,[3] colored with iron 3 ——— 100