2. The teachings of this science in physical geography are no less definite than the astounding disclosures which it makes in history—shadowing out, where mountain chains now rise, the seats of ancient sea bottoms—creeks and bays by lines of mudstones and conglomerates—continents that have been formed from islands, and islands disrupted from continents—lakes, estuaries, and rivers displaced and silted up, and now become the richest depositories of our mineral treasures. The connection of Great Britain with France is a matter almost of demonstration. A zone of primary crystalline rocks encompasses the western coast of both countries, whence geology follows them from Wales and Cornwall into Brittany and Normandy. The silurian, devonian, and carboniferous systems are arranged in the same order on both sides of the channel. Their chalk coasts are identical. A succession of elevating movements, depressions, and dislocations, is traceable everywhere along the southern counties of England, where the line of disturbance, from east to west, has separated the chalk on the north and south, and elevated the Wealden into an anticlinal axis on the Sussex coast. The Isle of Wight has been so shaken by the convulsion, as to have been literally tumbled over, the whole cretaceous formation, and every inferior deposit subjacent to the tertiaries, being in an inverted position. The existence, too, of a vast connecting stretch of land in the Atlantic is far from being improbable, whence the rivers of the Wealden may have issued, as well as much of the detrital matter been transported which now constitutes, with their remarkable and varied organic exuviæ, the basins of London, Hampshire, and Paris.