True Volcanoes. 2 *<} extremely abundant, which is not the cafe; and further, we know that beds of pyrites almott al ways occur in high mountains, and icarcely ever in fuch low fituations as are ufually occupied by volcanoes. -< Many other hypothefes have been propofedj and of thefe that of Werner, is the mod fatisfa&o- ry *■. ; ■ He is of opinion, that the commencement and continuance of pfeudo,- volcanoes and true volca noes, is caufed by the inflammation of beds of coal, only that in the cafe, of true volcanoes, greater beds of coal and a more folid covering are requi red than in pfeudo-volcanoes; and that this cover muft conlift of fuch rocks as yield a material for lava, as bafalt or wacke,A. principal condition is the rulhing in ot water as the immediate caule of the eruption. The.grounds for this, opinion are the following ; i. That immenle,beds of black-coal or mafles of brown-coal, occur in 1 many parts of the globe. As examples, may be mentioned, the grept bed on the. Meiflher, and that near Kiitterlchitz, in the vicinity of Bilin in Bohemia : the one has been pierced ninety feet, and the other tar deeper, without reaching the bottom of the bed. 2. r I hat beds of black-coal and brown-coal, in a flate of inflammation, * See Hopfner’s Magaz. fur. d. Naturklinde Helve- tiens, 4ter band S. 239. 234.