Sand generally seems to be nothing else but exceeding small Pebbles, or at
least some very small parcels of a bigger stone; the whiter kind seems
through the _Microscope_ to consist of small transparent pieces of some
_pellucid_ body, each of them looking much like a piece of _Alum_, or _Salt
Gem_; and this kind of Sand is angled for the most part irregularly,
without any certain shape, and the _granules_ of it are for the most part
flaw’d, through amongst many of them it is not difficult to find some that
are perfectly _pellucid_, like a piece of clear Crystal, and divers
likewise most curiously shap’d, much after the manner of the bigger
_Stiriæ_ of Crystal, or like the small Diamants I observ’d in certain
Flints, of which I shall by and by relate; which last particular seems to
argue, that this kind of Sand is not made by the comminution of greater
transparent Crystaline bodies, but by the _concretion_ or _coagulation_ of
Water, or some other fluid body.
There are other kinds of courser Sands, which are browner, and have their
particles much bigger; these, view’d with a _Microscope_, seem much courser
and more _opacous_ substances, and most of them are of some irregularly
rounded Figures; and though they seem not so _opacous_ as to the naked eye,
yet they seem very foul and cloudy, but neither do these want curiously
transparent, no more than they do regularly figur’d and well colour’d
particles, as I have often found.
There are multitudes of other kinds of Sands, which in many particulars,
plainly enough discoverable by the _Microscope_, differ both from these
last mention’d kinds of Sands, and from one another: there seeming to be as
great variety of Sands, as there is of Stones. And as amongst Stones some
are call’d precious from their excellency, so also are there Sands which
deserve the same Epithite for their beauty; for viewing a small parcel of
_East-India_ Sand (which was given me by my highly honoured friend, Mr.
_Daniel Colwall_) and, since that, another parcel, much of the same kind, I
found several of them, both very transparent like precious Stones, and
regularly figur’d like Crystal, _Cornish_ Diamants, some Rubies, &c. and
also ting’d with very lively and deep colours, like _Rubys_, _Saphyrs_,
_Emeralds_, &c. These kinds of granules I have often found also in _English_
Sand. And ’tis easie to make such a counterfeit Sand with deeply ting’d
Glass, Enamels and Painters colours.
It were endless to describe the multitudes of Figures I have met with in
these kind of minute bodies, such as _Spherical_, _Oval_, _Pyramidal_,
_Conical_, _Prismatical_, of each of which kinds I have taken notice.
But amongst many others, I met with none more observable than this pretty
Shell (described in the _Figure_ X. of the fifth _Scheme_) which, though as
it was light on by chance, deserv’d to have been omitted (I being unable to
direct any one to find the like) yet for its rarity was it not
inconsiderable, especially upon the account of the information it may
afford us. For by it we have a very good instance of the curiosity of
Nature in another kind of Animals which are remov’d, by reason of their
minuteness, beyond the reach of our eyes, so that as there are several
sorts of Insects, as Mites, and others, so small as not yet to have had any
names; (some of which I shall afterwards describe) and small Fishes, as
Leeches in Vinegar; and smal vegetables, as Moss, and Rose-Leave-plants;
and small Mushroms, as mould: so are there, it seems, small Shel-fish
likewise, Nature shewing her curiosity in every Tribe of _Animals_,
_Vegetables_, and _Minerals_.
I was trying several small and single Magnifying Glasses, and casually
viewing a parcel of white Sand, when I perceiv’d one of the grains exactly
shap’d and wreath’d like a Shell, but endeavouring to distinguish it with
my naked eye, it was so very small, that I was fain again to make use of
the Glass to find it; then, whilest I thus look’d on it, with a Pin I
separated all the rest of the granules of Sand, and found it afterwards to
appear to the naked eye an exceeding small white spot, no bigger than the
point of a Pin. Afterwards I view’d it every way with a better _Microscope_
and found it on both sides, and edge-ways, to resemble the Shell of a small
Water-Snail with a flat spiral Shell: it had twelve wreathings, a, b, c, d,
e, &c. all very proportionably growing one less than another toward the
middle or center of the Shell, where there was a very small round white
spot. I could not certainly discover whether the Shell were hollow or not,
but it seem’d fill’d with somewhat, and ’tis probable that it might be
_petrify’d_ as other larger Shels often are, such as are mention’d in the
seventeenth _Observation_.
* * * * *