Degrees, as the Letter K shews, which is an æqui-angular bexagonal Figure compounded
of twelve Globules : And in the same Manner, 25, or 27, or 36, or 42, &c. may be
combined.
Nor does it hold only in Superficies, but also in Solidity ; for 'tis beyond Dispute, that
if a fourth Globule be laid on the third in this Texture, it composes a regular Tetrabedron,
which is a very usual Figure amongst the Chrystals of Alum. And, indeed, amongst the
Variety of regular Shapes into which the smooth Surfaces of Alum are observed to be
chrystalized, there is not one but may be imitated by a such-like Position of Globules.
The cubical Forms of Sea-Salt and Sal-Gem, are also (our Author supposes) composed
of such a Position of Globules, as the Letter L shews. Vitriol, Salt-Petre, Chrystal, Hore-
Frost, &c. have likewise, he says, all their various Consigurations from Globules differently
combined.
An EXPLANATION of the FIFTH PLATE
This Plate exhibits several Kinds of Figures produced by Freezing, which
are extremely curious and wonderful, and deserve the Attention of all
diligent Observers of the Works of Nature.
PLATE V. FIG. 1.
One of the Six-branched Figures on the Surface of Urine, when it
begins to freeze
THESE Figures had usually a Center,
a, from whence the Branches extended them-
selves : And wherever a Center was, the Branchings from it, a b, a c, a d, a e,
a f, a g, were never more nor less than six, which all issued very nearly from the same
Point or Center a, tho' sometimes not exactly ; and inclined to one another, at an Angle
of about sixty Degrees, without any sensible Variation ; but as the whole six Branches
composed a solid Angle, they must necessarily be something less.
The Middle-Lines or Stems of these Branches, a b, a c, a d, a e, a f, a g, appeared
somewhat whiter, and a little higher than any of the intermediate Lines, seeming to rise
above the Surface of the Urine : And the Center a was evidently the most prominent of
the whole, resembling the Apex of a solid Angle or Pyramid.
The lateral Branchings from the six large Stems, such as o p, m q, &c. were each of
them inclined to the Stems from which they issued, at the same Angle (of about sixty De-
grees) as the said large Stems were to one another ; the bigger Branches always rising
higher than the less, and the less higher than the least, and so in proportionate Gradations.
These Side-Shoots were each of them parallel to that great Branch next which it lay ;
and all the Shoots on one Side were parallel to each other, as well as to the great Branch
next them. For Example : The lateral Shoots p o, q r, are parallel to one another, and
are also at the same time parallel to the large Branch a b.
Some of the Stems proceeded strait, and decreased in Thickness towards the End, as
a g. Others grew bigger and knotty towards the Middle ; and the Side-Shootings, as
well as the main Stems, from Cylinders became a Sort of semi-circular Planes, in a most
admirable and curious Order, and exceedingly delicate and regular, as may he seen at
a b, a c, a d, a e, a f: (These circular Figures, in the lateral Shoots, were also still
more remarkable at b i.) But towards the End of some of these Stems, they began again
to diminish and recover their former Branchings, as about k and n.
Such lateral Branches as q m, had many collateral Shootings, (if we may call them so)
as s, t ; most whereof had sub-collateral ones, as v, w ; which again had others less, and
those lesser ones had still minuter Shootings issuing from them.
The Branchings from the main Stems were not joined by any regular Line, nor did the
Side of one lie over that of the other ; but in the small collateral and sub-collateral Shoo?-
ings, one Branch lay over the Side of the next that approached to it, as the Feathers do
in a Bird's Wing, See the Figures 1, 2, 3, 4, 5, 6, 7, 8, 9, 10.
Many such-like Configurations were observed, of different Sizes, from the Bigness of a
Two-pence, to three or four Foot long, of which several were pretty round, having all
