rms of Vegetative bodies; and last of all, of
Animate ones, that seeming to be the highest step of natural knowledge that
the mind of man is capable of.
* * * * *
Observ. XIV. _Of several kindes of frozen _Figures_._
I have very often in a Morning, when there has been a great _hoar-frost_,
with an indifferently magnifying _Microscope_, observ'd the small
_Stiriae_, or Crystalline beard, which then usually covers the face of
most bodies that lie open to the cold air, and found them to be generally
_Hexangular prismatical_ bodies, much like the long Crystals of
_Salt-peter_, save onely that the ends of them were differing: for whereas
those of _Nitre_ are for the most part _pyramidal_, being terminated either
in a point or edge; these of Frost were hollow, and the cavity in some
seem'd pretty deep, and this cavity was the more plainly to be seen,
because usually one or other of the six _parallelogram_ sides was wanting,
or at least much shorter then the rest.
But this was onely the Figure of the _Bearded hoar-frost_; and as for the
particles of other kinds of _hoar-frosts_, they seem'd for the most part
irregular, or of no certain Figure. Nay, the parts of those curious
branchings, or _vortices_, that usually in cold weather tarnish the surface
of Glass, appear through the _Microscope_ very rude and unshapen, as do
most other kinds of frozen _Figures_, which to the naked eye seem exceeding
neat and curious, such as the Figures of _Snow_, frozen _Urine_, _Hail_,
several _Figures_ frozen in common Water, &c. Some Observations of each of
which I shall hereunto annex, because if well consider'd and examin'd, they
may, perhaps, prove very instructive for the finding out of what I have
endeavoured in the preceding Observation to shew, to be (next the _Globular
Figure_ which is caus'd by _congruity_, as I hope I have made probable in
the sixth _Observation_) the most simple and plain operation of Nature, of
which, notwithstanding we are yet ignorant.
I.
_Several Observables in the _six-branched_ Figures form'd on the surface of
Urine by freezing._
1 [11]The Figures were all frozen almost even with the surface of the
_Urine_ in the Vessel; but the bigger stems were a little _prominent_ above
that surface, and the parts of those stems which were nearest the center
(a) were biggest above the surface.
2 I have observ'd several kinds of these Figures, some smaller, no bigger
then a Tw
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