We thus shall find the greatest part of the calcareous masses upon this globe to have originated from marine calcareous bodies; for whether we examine marbles, limestones, or such solid masses as are perfectly changed from the state of earth, and are become compact and hard, or whether we examine the soft, earthy, chalky or marly strata, of which so much of this earth is composed, we still find evident proofs, that those beds had their origin from materials deposited at the bottom of the sea; and that they have the calcareous substance which they contain, from the same source as the marbles or the limestones.

2_dly_, In those calcareous strata, which are evidently of marine origin, there are many parts that are of a sparry structure, that is to say, the original texture of those beds, in such places, has been dissolved, and a new structure has been assumed, which is peculiar to a certain state of the calcareous earth.  This change is produced by crystallisation, in consequence of a previous state of fluidity, which has so disposed the concreting parts, as to allow them to assume a regular shape and structure proper to that substance.  A body, whose external form has been modified by this process, is called a crystal; one whose internal arrangement of parts is determined by it, is said to be of a sparry structure; and this is known from its fracture.

3_dly_, There are, in all the regions of the earth, huge masses of calcareous matter, in that crystalline form of sparry state, in which perhaps no vestige can be found of any organised body, nor any indication that such calcareous matter had belonged to animals; but as, in other masses, this sparry structure, or crystalline state, is evidently assumed by the marine calcareous substances, in operations which are natural to the globe, and which are necessary to the consolidation of the strata, it does not appear, that the sparry masses, in which no figured body is formed, have been originally different from other masses, which, being only crystallised in part, and in part still retaining their original form, leave ample evidence of their marine origin[3].

[Note 3:  M. de Saussure, describing the marble of Aigle, says, “Les tables polies de ce marbre presentent frequemment des coquillages, dont la plupart sont des peignes stries, et de tres-beaux madrepores.  Tous ces corps marins on pris entierement la nature et le grain meme du marbre, on n’y voit presque jamais la coquille sous sa forme originaire.”]

We are led, in this manner, to conclude, that all the strata of the earth, not only those consisting of such calcareous masses, but others superincumbent upon these, have had their origin at the bottom of the sea, by the collection of sand and gravel, of shells, of coralline and crustaceous bodies, and of earths and clays, variously mixed, or separated and accumulated.  Here is a general conclusion, well authenticated in the appearances of nature, and highly important in the natural history of the earth.