243. One of the most ingenious attempts to support the volcanic theory, is the system of _submarine volcanoes_, imagined by the celebrated mineralogist DOLOMIEU. The phenomenon that led to this hypothesis, was what he had observed in the hills near Lisbon, and still more remarkably in those of the Val di Noto in Sicily, where the basaltine rocks had regular strata incumbent on them, and in some cases interposed or alternated with them.[128] It seemed from this evident, that the strata were of later formation than the stone on which they rested; and as they must, on every supposition, be held to be deposited by water, it was concluded, that the lava which they covered had been thrown out by volcanoes at the bottom of the sea; that the strata had afterwards been deposited on this lava; and that, in some cases, there had been frequent alternations of these eruptions and depositions.[129] [Footnote 128: Mémoire de Deodate de Dolomieu, sur les Volcains Eteints du Val di Noto, en Sicile. Journal de Phys. tom. xxv. (1784. Septembre.) p. 191.] [Footnote 129: Near Vizini, in the Val di Noto, Dolomieu tells us, that he counted eleven beds, alternately calcareous and volcanic, in the perpendicular face of a hill, which at a distance appeared like a piece of cloth, striped black and white; _ubi supra_. He has since made similar observations in the Vicentine and in Tyrol. Journal de Phys. tom. xxxvii. (1790), partie 2, p. 200.] 244. Though this hypothesis does certainly deliver the system of the Volcanists from one great difficulty, it is itself liable to insurmountable objections. I shall just mention some of the principal. 1. The regular and equidistant strata that we often see covering the tops of whinstone or basaltic rocks, could not have been deposited in the oblique and very much inclined position which they now occupy. This is remarkable in the strata which cover the basaltic rock of Salisbury _Craig_, near Edinburgh, at its northern extremity. The strata are very regular, and must have been deposited in a plane nearly horizontal; yet the surface of the basaltes on which they now rest is very much inclined, dipping rapidly to the north-east. The necessity of a horizontal deposition in strata, which, though not now horizontal, have their planes nearly parallel to one another, has been proved at § 38. 2. If there is any truth in the principles established above, even the strata themselves have not been consolidated without the action of fire. By Dolomieu's system, therefore, the consolidation of the strata which cover the basaltes is not accounted for.