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VI. Qn the whole, the more perfectly the Concretion has been formed, and the more equal in its conſtituent Parts the concreting Matter was, the more does the Concrete poſſeſs the peculiar Properties which are owing to that Equality.
Beds of weightier Matter, which its immenſe and irreſiſtible Force had taken up, and now in its abating ſuffered to ſubſide again.
This, allowing alſo for the Alterations made by Earthquakes, afterwards burſting, and elevating or ſinking the Strata in many Places, is the preſent Condition of the outer Cruſt of this Earth to a certain Depth, far within which perhaps all our Reſearches lie; and in this Maſs we find, according to the Syſtem 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 Fiſſures of thoſe Strata, and ſome other Places, Cryſtals, Spars, and other like ſubſtances, ſeparated by Percolation from the arenaceous, argillaceous, and other Matter, among which they ſubſided in their ſeparated Particles; being there brought together by the continual draining of Water through the ſolid Strata; which in its Paſſage had taken them up with it, and there deſerted them in different Manners; and left them to aſſume the Figures which are the natural and neceſſary Conſequences of their Concretions.
Theſe then are the two general Methods of Formation of thoſe Bodies mentioned by our Author; the various others, which he hints at as taking Place in ſome particular Caſes, are too numerous to be all recited here: Terreſtrial and ſparry Matter, waſhed from the Strata by the Water of Springs in their Paſſage, and ſubſiding at ſome Diſtance from their Source, round various Subſtances in Form of Incruſtations, is one: Matter of a like Kind, and ſeparated in a like Manner, dropping from the Tops of Caverns with the Water; and either deſerted by it at the Top, and left in Form of Icicles or
