[_While stern Bastile_. l. 383. "We descended with great difficulty into the dungeons, which were made too low for our standing upright; and were so dark, that we were obliged at noon-day to visit them by the light of a candle. We saw the hooks of those chains, by which the prisoners were fastened by their necks to the walls of their cells; many of which being below the level of the water were in a constant state of humidity; from which issued a noxious vapour, which more than once extinguished the candles. Since the destruction of the building many subterraneous cells have been discovered under a piece of ground, which seemed only a bank of solid earth before the horrid secrets of this prison-house were disclosed. Some skeletons were found in these recesses with irons still fastened to their decayed bones." Letters from France, by H.M. Williams, p. 24.] 395 VII. "GNOMES! YOU then taught volcanic airs to force Through bubbling Lavas their resistless course, O'er the broad walls of rifted Granite climb, And pierce the rent roof of incumbent Lime, Round sparry caves metallic lustres fling, 400 And bear phlogiston on their tepid wing. [_And pierce the rent roof_. l. 398. The granite rocks and the limestone rocks have been cracked to very great depths at the time they were raised up by subterranean fires; in these cracks are found most of the metallic ores, except iron and perhaps manganese, the former of which is generally found in horizontal strata, and the latter generally near the surface of the earth. Philosophers possessing so convenient a test for the discovery of iron by the magnet, have long since found it in all vegetable and animal matters; and of late Mr. Scheele has discovered the existence of manganese in vegetable ashes. Scheele, 56 mem. Stock. 1774. Kirwan. Min. 353. Which accounts for the production of it near the surface of earth, and thence for its calciform appearance, or union with vital air. Bergman has likewise shewn, that the limestones which become bluish or dark coloured when calcined, possess a mixture of manganese, and are thence preferable as a cement to other kinds of lime. 2. Bergman, 229. Which impregnation with manganese has probably been received from the decomposition of superincumbent vegetable matters.