ont to be employed in
the making it, does by its Tenacity oppose the operations of the above
mention'd Saline liquors. But to consider Gum no more, what some kind of
Praecipitation may have to do in the producing and destroying of Inks
without it, I have elsewhere given you some occasion and assistance to
enquire; But I must not now stay to do so my self, only I shall take notice
to you, that though it be taken for granted that bodies will not be
Praecipitated by Alcalizat Salts, that have not first been dissolved in some
Acid _Menstruums_, yet I have found upon tryals, which my conjectures lead
me to make on purpose, That divers Vegetables _barely infus'd_, or, _but
slightly decocted in common water_, would, upon the affusion of a Strong
and Cleer _Lixivium_ of Potashes, and much more of some other Praecipitating
liquors that I sometimes employ, afford good store of a Crudled matter,
such as I have had in the Praecipitations of Vegetable substances, by the
intervention of Acid things, and that this matter was easily separable from
the rest of the liquor, being left behind by it in the Filtre; and in
making the first Ink mention'd in this Experiment, I found that I could by
Filtration separate pretty store of a very Black pulverable substance, that
remain'd in the Filtre, and when the Ink was made Cleer again by the Oyl of
Vitriol, the affusion of dissolv'd _Sal Tartari_ seem'd but to Praecipitate,
and thereby to Unite and render Conspicuous the particles of the Black
mixture that had before been dispers'd into very Minute and singly
Invisible particles by the Incisive and resolving power of the highly
Corrosive Oyl of Vitriol.

And to manifest, _Pyrophilus_, that Galls are not so requisite as many
suppose to the making Atramentous Liquors, we have sometimes made the
following Experiment, We took dryed Rose leaves and Decocted them for a
while in Fair Water, into two or three spoonfulls of this Decoction we
shook a few drops of a strong and well filtrated Solution of Vitriol (which
perhaps had it been Green would have done as well) and immediately the
mixture did turn Black, and when into this mixture presently after it was
made, we shook a just Proportion of _Aqua Fortis_, we turn'd it from a
Black Ink to a deep Red one, which by the affusion of a little Spirit of
Urine may be reduc'd immediately to an Opacous and Blackish Colour. And in
regard, _Pyrophilus_, that in the former Experiments, both the Infusion of
Galls, a