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Seconä Appendix, C Of Compadt Lava By compaft lava, volcanic writers denote arj earthy fubftance, which, after having been fufecj but not vitrified, becomes, on cooling, compaft, clofe, and folid. Whethcrthis degrecoffolidity is fuch as totally to exciude that evidently porous and cavernous Itrudure, which ccdlular lava prefents, is not perfedly agreed upoiv ... , ■ . Thofe who are guided by obfervation on pnodern and undjfoutcd volcanic- torrents, aJlow i ' ’ 1 • ■- • .. j* J. j f r 'f • »•/. k / that no lava abfolut^j.y.'compajl, and dcüitute .gf p^rof jti ai) extepV'of inore than a fewfquare inches ts’cver found. '' Tims' Mr. “Bergman defin.es, pompaft .)a.vas, |^, “ thofe'Wbich, t! though not abfolutei^’deftltüte'of.cavitics, yct “ c.oofajq fc.few, thäLfhey Way be cat'ihtö. flabs “ with.nn äjmo^t'iptire furfacei jand polifhcd <{ like mprble.” 3 Bergm. p. 201. To this dc- finitio.n* L4r. Dolomieu, , in bis noles oii Bcrg- rnatfs Bilfertatipn, ' makes no objeflionj from vvhich we may corrduije, that in a fmall extern, fuch asthat of common inarble flabs, they never pxhibit ap vninterruptyd (urface. This 1 alt nren- tion^d rHilolbpher, iiidccd, havirig unfortunatcJy wilhed tö compreheiuT, in his definition of corh- pad l^va, ftony malles, not found in modern and uridiTputed beds of lava, but in fupp'oßd aritknt, 5 currents,