concerning Salt-petre, that none of the substances into which the Fire
is wont to divide it, retaines either the Tast, the cooling vertue, or
some other of the properties of the Concrete; and that each of those
Substances acquires new qualities, not to be found in the Salt-Petre
it self. The shining property of the tayls of gloworms does survive
but so short a time the little animal made conspicuous by it, that
inquisitive men have not scrupled publickly to deride _Baptista Porta_
and others; who deluded perhaps with some Chymical surmises have
ventur'd to prescribe the distillation of a Water from the tayles of
Glowormes, as a sure way to obtain a liquor shining in the Dark. To
which I shall now add no other example than that afforded us by Amber;
which, whilst it remains an intire body, is endow'd with an Electrical
faculty of drawing to it self fethers, strawes, and such like Bodies;
which I never could observe either in its Salt, its Spirit, its Oyle,
or in the Body I remember I once made by the reunion of its divided
Elements; none of these having such a Texture as the intire Concrete.
And however Chymists boldly deduce such and such properties from this
or that proportion of their component Principles; yet in Concretes
that abound with this or that Ingredient, 'tis not alwayes so much by
vertue of its presence, nor its plenty, that the Concrete is qualify'd
to perform such and such Effects; as upon the account of the
particular texture of that and the other Ingredients, associated after
a determinate Manner into one Concrete (though possibly such a
proportion of that ingredient may be more convenient than an other for
the constituting of such a body.) Thus in a clock the hand is mov'd
upon the dyal, the bell is struck, and the other actions belonging to
the engine are perform'd, not because the Wheeles are of brass or
iron, or part of one metal and part of another, or because the weights
are of Lead, but by Vertue of the size, shape, bigness, and
co-aptation of the several parts; which would performe the same things
though the wheels were of Silver, or Lead, or Wood, and the Weights of
Stone or Clay; provided the Fabrick or Contrivance of the engine were
the same: though it be not to be deny'd, that Brasse and Steel are
more convenient materials to make clock-wheels of than Lead, or Wood.
And to let you see, _Eleutherius_, that 'tis sometimes at least, upon
the Texture of the small parts of a body, and not alwaies upon the
presence, or recesse, or increase, or Decrement of any one of its
Principle, that it may lose some such Qualities, and acquire some
such others as are thought very strongly inherent to the bodies they
Reside in. [Errata: in;] I will add to what may from my past discourse
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