IV. Take the sharpest juice of grapes, and being distilled,

dissolve into a clear cristalline water, the body being well
calcined to a redness, which is by the philosophers called se-
ricon ; of which, make a gum, which is like allum in taste,
and is by Raymond called azoquean vitriol. Out of this gum
with a slow fire is drawn first a weak water, which hath in its
taste no sharpness, no more than spring-water; — and when a
white fume begins to appear, then change the receiver, aud
lute strongly, that it may no way expire ; and so you will have
your aqua ardens, aqua vita?, and a resolvative menstruum,
which before was resolvable. This is the potential vapour,
able to dissolve, putrify, and also purify bodies, divide the ele-
ments, and by its attractive virtue exalt its own earth into a
wonderful salt ; and they that think there is any other water,
besides this which we speak of, are mistaken in this work : this
water hath a most sharp taste, and partly also a stinking smell,
and therefore is called stinking menstruum ; and it being a very
airy water, it therefore ought to be put upon its calxes in
less than an hour after it is distilled or rectified ; — but when it
is poured upon the aforesaid calxes, it begins to boil up, and
then if the vessel be well stopped, it will not leave working,
though no fire be administered to it from without, till it be
dried up in the calx ; — wherefore you must apply no greater
quantity of it than scarce to cover the calxes ; — then proceed to
the full completing of it, as in the work of the compounded
water. And when the elixir is reduced to a purple colour, let
it be dissolved in the same menstruum, being first rectified into
a thin oil, upon which fix the spirit of our water by circu-
lation, and then hath it the power of converting all bodies
into most pure gold, and to heal all infirmities of man's bodj',
more than all the potions of Hippocrates and Galen, for this is
the true aurum potabile, and no other, which is made of artificial
gold elemented, turned about by the wheel of philosophy, &c. —
Medulla Phil. Chcm. p. 170.