re become
Transparent, which you may, if you please, again reduce to a good degree of
Whiteness (though inferiour to the first) onely by a more copious affusion
of fresh Spirit of Urine. _N_. First, That it is not so necessary to employ
either _Aqua Fortis_ or Spirit of Urine about this Experiment, but that we
have made it with other liquors instead of these, of which perhaps more
elsewhere. Secondly, That this Experiment, though not made with the same
_Menstruums_, nor producing the same Colour is yet much of Kin to that
other to be mentioned in this Tract among our other Experiments of Colours,
about turning a Solution of Praecipitate into an Orange-colour, and the
Chymical Reason being much alike in both, the annexing it to one of them
may suffice FOR both.

_EXPERIMENT II._

Make a strong Infusion of broken Galls in Fair Water, and having Filtred it
into a clean Vial, add more of the same liquor to it, till you have made it
somewhat Transparent, and sufficiently diluted the Colour, for the credit
of the Experiment, lest otherwise the Darkness of the liquor might make it
be objected, that 'twas already almost Ink; Into this Infusion shake a
convenient quantity of a Cleer, but very strong Solution of Vitriol, and
you shall immediately see the mixture turn Black almost like Ink, and such
a way of producing Blackness is vulgar enough; but if presently after you
doe upon this mixture drop a small quantity of good oyl of Vitriol, and, by
shaking the Vial disperse it nimbly through the two other liquors, you
shall (if you perform your part well, and have employ'd oyl of Vitriol
Cleer and Strong enough) see the Darkness of the liquor presently begin to
be discuss'd, and grow pretty Cleer and Transparent, losing its Inky
Blackness, which you may again restore to it by the affusion of a small
quantity of a very strong Solution of Salt of Tartar. And though neither of
these Atramentous liquors will seem other than very Pale Ink, if you write
with a clean Pen dipt in them, yet that is common to them with some sorts
of Ink that prove very good when Dry, as I have also found, that when I
made these carefully, what I wrote with either of them, especially with the
Former, would when throughly Dry grow Black enough not to appear bad Ink.
This Experiment of taking away and restoring Blackness from and to the
liquors, we have likewise tryed in Common Ink; but there it succeeds not so
well, and but very slowly, by reason that the Gum w