contingent in any of thofe Circumftances. This will not be thought an over-great Exactness, or any thing more than was needful, by thofe who have noted how much Philofophy hath fuffered by the Neglect and Overfight of fome Naturalifts in this Refpect. A tranfient and perfundory Examination of Things, frequently leads Men into confiderable Miftakes, which a more correct and rigorous Scrutiny would have detected and avoided. The Truth is, I have been the more fcrupulous and wary in regard the Inferences drawn from thefe Obfervations are of fome Importance. Twas but neceffary that the Foundation fhould be firm, when a Superftructure of Bulk and Weight was to be rais'd upon it. And therefore I advance nothing from any Obfervation that was not made with this Caution, and that any Man may not, as well as my felf, without any great Pains, inform himself of the Truth of. Now, as long as the next Cole-pit, or Mine, the next Quarry, or Chalkpit, will give abundant Atteftation to what I write, thefe are fo ready

and

and obvious in almoft all Places, that I need not be any where far to feek for a Compurgator: and to thefe I may very fafely appeal.

Concerning the Obfervations themfelves therefore, there cannot well arife any Doubt but what may eafily be fatisfy'd and what I propose in this Effay being founded upon thefe Obfervations, every Reader will be Judge of the Truth and Probability of it, and whether that which I do fo propofe naturaly follows from them or not.

I fhall diftribute them into two general Claffes or Sections, whereof the former will comprehend my Obfervations upon all the Terreftrial Matter that is naturaly difpofed into Layers, or Strata; fuch as our common Sand-Stone, Marble, Cole, Chalk, all Sorts of Earth, Marle, Clay, Sand, with fome others.

Of this various Matter, thus formed into Strata, the far greatest Part of the Terreftrial Globe confifts, from its Surface downwards to the greateft Depth we ever dig or mine. And it is upon my Obfervations on this that I have grounded all my general Conclu

B 3

Conclufions concerning the Earth: all that relate to its Form: all that relate to the Univerfal and other Deluges in a Word, all that relate to the feveral Viciffitudes and Alterations that it hath yet undergone. Nay, upon the fame Obfervations I have alfo founded feveral Conclufions touching Metalls, Spar, and other Minerals, which are found lodged either in thefe Strata, amongst the Sand, Chalk, Earth, and the reft or in the perpendicular Intervalls of the Strata of Stone, Marble, or other folid Matter.

For upon the particular Obfervations on the faid Metallick and Mineral Bodies, (which are the Subjects of the fecond Section,) I have not founded any thing but what purely and immediately concerns the Natural Hiftory of thofe Bodies.

To proceed therefore to the Account of my Obfervations upon Sand-ftone. And in thefe, though I do not neglect to note the feveral Kinds or Varieties of it: Free-ftone, Ragg-ftone, Lime-ftone, and the reft the different Hardnefs, or Solidity, of each as alfo its Colour,

Texture,

*

Texture, and the peculiar Matter which conftitutes it; yet I confine my felf more ftrictly to confider the Manner how 'tis difpofed in the Earth the Strata, into which, by means of horizontal and parallel Fiffures, it is divided: the Order and Number of thefe Strata: their Situation in refpect of the Horizon: the Thickness, Depth, and other Circumftances of each: the Interruptions of the Strata, I mean the perpendicular Fiffures, which interfect the horizontal ones: the different Capacity or Largeness of these perpendicular Intervalls: their Diftances from each other: and the Spar, and other Mineral and Metallick Matter, ufualy contained in them.

*

But, because I saw that Deductions of confiderable Import and Confequence might be drawn from them, I have with great Care and Intention obferved the Condition of such beteB 4 rogeneous

.*. I call thofe Fiffures, which distinguish the Stone into Strata, Horizontal ones and thofe which interfect thefe, Perpendicular; not fo much with refpect to the prefent Site of the Strata, which is alter'd, in many Places, and now much different from their original Situation, concerning which, fee Part 2. Confect. 5, & 6.

rogeneous Bodies, which I found immerfed and included in the Mafs of this Sand-fone; particularly the Shells of Oyfters, Mufeles, Scallopes, Cockles, Periwincles, and very many other marine Productions. I have, I fay, very diligently noted all Circumftances of thefe Shells: the vaft Numbers of them: the feveral Kinds that are thus lodged in the Subftance of the Stone: the Order and Manner of their Pofition in it: the feveral Depths at which they are found the Matter which they contain in them, and wherewith their Cavities are ufualy filled.

Thefe Obfervations about Stone are fucceeded by others, of like Nature, concerning Marble, Cole, and Chalk: their Fiffures: the Situation of their Strata: the Shells, and other heterogeneous Bodies lodged therein.

In the next Place, thofe which concern Marle, Clay, the feveral Kinds of Earth, Sand, and fome other Fofils the Shells and other like Bodies, lodged in their Strata : the Pofition of thofe Stata: their Order their Diftinctions from each other, by the Difference of the

Matter