And from this I shall proceed to a second considerable _Phænomenon_ which these Diamants exhibit, and that is the regularity of their _Figure_, which is a propriety not less general than the former, It comprising within its extent, all kinds of _Metals_, all kinds of _Minerals_, most _Precious stones_, all kinds of _Salts_, multitudes of _Earths_, and almost all kinds of _fluid bodies_. And this is another propiety, which, though a little superficially taken notice of by some, has not, that I know, been so much as attempted to be explicated by any.
This propriety of bodies, as I think it the most worthy, and next in order to be consider’d after the contemplation of the _Globular Figure_, so have I long had a desire as wel as a determination to have prosecuted it if I had had an opportunity, having long since propos’d to my self the method of my enquiry therein, it containing all the allurements that I think any enquiry is capable of: For, first I take it to proceed from the most simple principle that any kind of form can come from, next the _Globular_, which was therefore the first I set upon, and what I have therein perform’d, I leave the Judicious Reader to determine. For as that form proceeded from a propiety of fluid bodies, which I have call’d _Congruity_, or _Incongruity_; so I think, had I time and opportunity, I could make probable, that all these regular Figures that are so conspicuously _various_ and _curious_, and do so adorn and beautifie such multitudes of bodies, as I have above hinted, arise onely from three or four several positions or postures of _Globular_ particles, and those the most plain, obvious, and necessary conjunctions of such figur’d particles that are possible, so that supposing such and such plain and obvious causes concurring the _coagulating particles_ must necessarily compose a body of such a determinate regular Figure, and no other, and this with as much necessity and obviousness as a fluid body encompast with a _Heterogeneous_ fluid must be protruded into a _Spherule_ or _Globe_. And this I have _ad oculum_ demonstrated with a company of bullets, and some few other very simple bodies; so that there was not any regular Figure, which I have hitherto met withall, of any of those bodies that I have above named, that I could not with the composition of bullets or globules, and one or two other bodies, imitate, even almost by shaking them together. And thus for instance may we find that the _Globular_ bullets will of themselves, if put on an inclining plain, so that they may run together, naturally run into a _triangular_ order, composing all the variety of figures that can be imagin’d to be made out of _æquilateral triangles_; and such will you find, upon trial, all the Surfaces of _Alum_ to be compos’d of: For three bullets lying on a plain, as close to one another as they can compose an _æquilatero-triangular_ form, as in A in the 7. _Scheme_. If a fourth be joyn’d to them on either side as closely as it can, they four compose the most regular Rhombus consisting of two _æquilateral triangles_, as B. If a fifth be joyn’d to them on either side in as close a position as it can, which is the propriety of the _Texture_, it makes a _Trapezium_, or four-sided Figure, two of whose angles are 120. and two 60. degrees, as C. If a sixth be added, as before, either it makes an _æquilateral triangle_, as D, or a Rhomboeid, as E, or an _Hexangular Figure_, as F, which is compos’d of two _primary Rhombs_. If a seventh be added, it makes either an _æquilatero-hexagonal_ Figure, as G, or some kind of six-sided _Figure_, as H, or I. And though there be never so many placed together, they may be rang’d into some of these lately mentioned Figures, all the angles of which will be either _60_. degrees, or 120. as the figure K. which is an _æquiangular hexagonal_ Figure is compounded of 12. _Globules_, or may be of 25, or 27, or 36, or 42, &c. and by these kinds of texture, or position of globular bodies, may you find out all the variety of regular shapes, into which the smooth surfaces of _Alum_ are form’d, as upon examination any one may easily find; nor does it hold only in superficies, but in solidity also, for it’s obvious that a fourth _Globule_ laid upon the third in this texture, composes a regular _Tetrahedron_, which is a very usual Figure of the _Crystals_ of _Alum_. And (to hasten) there is no one Figure into which _Alum_ is observ’d to be crystallized, but may by this texture of _Globules_ be imitated, and by no other.