Sec. 47. Then he consider'd further, whether this Three-fold _Extension_, was the very Essence of Body or not; and quickly found, that besides this _Extension_, there was another, in which this Extension did exist, and that this Extension could not subsist by it self, as also the Body which was extended, could not subsist by it self without Extension. This he experimented in some of those sensible Bodies which are endu'd with Forms; for Example, in Clay: Which he perceiv'd, when moulded into any Figure, (Spherical suppose) had in it a certain Proportion, Length, Breadth, and Thickness. But then if you took that very same Ball, and reduc'd it into a Cubical or Oval Figure, the Dimensions were chang'd, and did not retain the same Proportion which they had before, and yet the Clay still remain'd the same, without any Change, only that it was necessary for it to be extended into Length, Breadth, and Thickness, in some Proportion or other, and not be depriv'd of its Dimensions: Yet it was plain to him from the successive Alterations of them in the same Body, that they were distinct from the Clay itself; as also, that because the Clay could not be altogether without them, it appear'd to him that it belong'd to its Essence. And thus from this Experiment it appear'd to him, that Body consider'd as Body, was compounded of two Properties: The one of which represents the _Clay_, of which the Sphere was made; The other, the _Threefold Expression_ of it, when form'd into a Sphere, Cube, or what other Figure soever. Nor was it possible to conceive _Body_, but as consisting of these two Properties, neither of which could subsist without the other. But that one (namely, that of Extension) which was liable to Change, and could successively put on different Figures, did represent the Form in all those Bodies which had Forms. And that other which still abode in the same State, (which was the _Clay_, in our last Instance) did represent _Corporeity,_ which is in all Bodies, of what Forms soever. Now that which we call _Clay_ in the foregoing Instance, is the same which the Philosophers call _Materia prima_ [the first Matter] and [Greek: Hyle], which is wholly destitute of all manner of Forms.