d?

When _Aqua fortis_ dissolves Silver and not Gold, and _Aqua regia_
dissolves Gold and not Silver, may it not be said that _Aqua fortis_ is
subtil enough to penetrate Gold as well as Silver, but wants the
attractive Force to give it Entrance; and that _Aqua regia_ is subtil
enough to penetrate Silver as well as Gold, but wants the attractive
Force to give it Entrance? For _Aqua regia_ is nothing else than _Aqua
fortis_ mix'd with some Spirit of Salt, or with Sal-armoniac; and even
common Salt dissolved in _Aqua fortis_, enables the _Menstruum_ to
dissolve Gold, though the Salt be a gross Body. When therefore Spirit of
Salt precipitates Silver out of _Aqua fortis_, is it not done by
attracting and mixing with the _Aqua fortis_, and not attracting, or
perhaps repelling Silver? And when Water precipitates Antimony out of
the Sublimate of Antimony and Sal-armoniac, or out of Butter of
Antimony, is it not done by its dissolving, mixing with, and weakening
the Sal-armoniac or Spirit of Salt, and its not attracting, or perhaps
repelling the Antimony? And is it not for want of an attractive virtue
between the Parts of Water and Oil, of Quick-silver and Antimony, of
Lead and Iron, that these Substances do not mix; and by a weak
Attraction, that Quick-silver and Copper mix difficultly; and from a
strong one, that Quick-silver and Tin, Antimony and Iron, Water and
Salts, mix readily? And in general, is it not from the same Principle
that Heat congregates homogeneal Bodies, and separates heterogeneal
ones?

When Arsenick with Soap gives a Regulus, and with Mercury sublimate a
volatile fusible Salt, like Butter of Antimony, doth not this shew that
Arsenick, which is a Substance totally volatile, is compounded of fix'd
and volatile Parts, strongly cohering by a mutual Attraction, so that
the volatile will not ascend without carrying up the fixed? And so, when
an equal weight of Spirit of Wine and Oil of Vitriol are digested
together, and in Distillation yield two fragrant and volatile Spirits
which will not mix with one another, and a fix'd black Earth remains
behind; doth not this shew that Oil of Vitriol is composed of volatile
and fix'd Parts strongly united by Attraction, so as to ascend together
in form of a volatile, acid, fluid Salt, until the Spirit of Wine
attracts and separates the volatile Parts from the fixed? And therefore,
since Oil of Sulphur _per Campanam_ is of the same Nature with Oil of
Vitriol, may it not be