Page:Theophrastus - History of Stones - Hill (1774).djvu/31

 Beds of weightier Matter, which its immene and irreitible Force had taken up, and now in its abating uffered to ubide again.

This, allowing alo for the Alterations made by Earthquakes, afterwards burting, and elevating or inking the Strata in many Places, is the preent Condition of the outer Crut of this Earth to a certain Depth, far within which perhaps all our Reearches lie; and in this Mas we find, according to the Sytem of our Author, the Strata of Stone and Earth, formed by the Concretion of Matter, equal in Weight and many other of its Properties, and brought together in that State by mere Afflux, by means of the Action of Gravity: and in the perpendicular Fiures of thoe Strata, and ome other Places, Crytals, Spars, and other like ubtances, eparated by Percolation from the arenaceous, argillaceous, and other Matter, among which they ubided in their eparated Particles; being there brought together by the continual draining of Water through the olid Strata; which in its Paage had taken them up with it, and there deerted them in different Manners; and left them to aume the Figures which are the natural and neceary Conequences of their Concretions.

Thee then are the two general Methods of Formation of thoe Bodies mentioned by our Author; the various others, which he hints at as taking Place in ome particular Caes, are too numerous to be all recited here: Terretrial and parry Matter, wahed from the Strata by the Water of Springs in their Paage, and ubiding at ome Ditance from their Source, round various Subtances in Form of Incrutations, is one: Matter of a like Kind, and eparated in a like Manner, dropping from the Tops of Caverns with the Water; and either deerted by it at the Top, and left in Form of Icicles or VI. Qn the whole, the more perfectly the Concretion has been formed, and the more equal in its contituent Parts the concreting Matter was, the more does the Concrete poes the peculiar Properties which are owing to that Equality.