in a Crystal Vial did manifestly disclose any Tincture, only it seem'd
sometimes not to be quite destitute of a little, but very faint
Blewishness.

But here I must take notice, that of all the Metalls, there is not any
which doth so easily and constantly disclose its unobvious colour as Copper
doth. For not only in acid _Menstruums_ as _Aqua Fortis_ and Spirit of
Vinegar, it gives a Blewish green solution, but if it be almost any way
corroded, it _appears of one of those_ two colours, as may be observ'd in
Verdigreese made several wayes, in that odd preparation of _Venus_, which
we elsewhere teach you to make with Sublimate, and in the common Vitriols
of _Venus_ deliver'd by Chymists; and so constant is the disposition of
Copper, notwithstanding the disguise Artists put upon it, to disclose the
colour we have been mentioning, that we have by forcing it up with _Sal
Armoniack_ obtain'd a Sublimate of a Blewish Colour. Nay a famous Spagyrist
affirms, that the very Mercury of it is green, but till he teach us an
intelligible way of making such a Mercury, we must content ourselves to
inform you, that we have had a Cupreous Body, that was Præcipitated out of
a distill'd Liquor, that seem'd to be the the Sulphur of _Venus_, and
seem'd even when flaming, of a Greenish Colour. And indeed Copper is a
Metall so easily wrought upon by Liquors of several kinds, that I should
tell you, I know not any Mineral, that will concurr to the production of
such a variety of Colours as Copper dissol'd in several _Menstruums_, as
Spirit of Vinegar, _Aqua fortis_, _Aqua Regis_, Spirit of Nitre, of Urine,
of Soot, Oyls of several kinds, and I know not how many other Liquors, if
the variety of somewhat differing colours (that Copper will be made to
assume, as it is wrought upon by several Liquors) were not comprehended
within the Limits of Greenish Blew, or Blewish Green.

And yet I must advertise you (_Pyrophilus_) that being desirous to try if I