nor_.

_Annotation upon the one and twentieth Experiment._

But lest you should be tempted to think (_Pyrophilus_) that Volatile or
Alcalizate Salts change Blews into Green, rather upon the score of the
easie Transition of the former Colour into the latter, than upon the
account of the Texture, wherein most Vegetables, that afford a Blew, seem,
though otherwise differing, to be Allied, I will add, that when I purposely
dissolv'd Blew Vitriol in fair Water, and thereby imbu'd sufficiently that
Liquor with that Colour, a Lixiviate Liquor, and a Urinous Salt being
Copiously pour'd upon distinct Parcels of it, did each of them, though
perhaps with some Difference, turn the Liquor not Green, but of a deep
Yellowish Colour, almost like that of Yellow Oker, which Colour the
Precipitated Corpuscles retain'd, when they had Leisurely subsided to the
Bottom. What this Precipitated Substance is, it is not needfull now to
Enquire in this place, and in another, I have shown you, that
notwithstanding its Colour, and its being Obtainable from an Acid
_Menstruum_ by the help of Salt of Tartar, it is yet far enough from being
the true Sulphur of Vitriol.

_EXPERIMENT XXII._

Our next Experiment (_Pyrophilus_) will perhaps seem to be of a contrary
Nature to the two former, made upon Syrrup of Violets, and Juice of
Blew-bottles. For as in them by the Affusion of Oyl of Tartar, a Blewish
Liquor is made Green, so in this, by the sole Mixture of the same Oyl, a
Greenish Liquor becomes Blew. The hint of this Experiment was given us by
the practice of some _Italian_ Painters, who being wont to Counterfeit
_Ultra-marine Azure_ (as they call it) by Grinding Verdigrease with
Sal-Armoniack, and some other Saline Ingredients, and letting them Rot (as
they imagine) for a good while together in a Dunghill, we suppos'd, that
the change of Colour wrought in the Verdigrease by this way of Preparation,
must proceed from the Action of certain Volatile and Alcalizate Salts,
abounding in some of the mingled Concretes, and brought to make a further
Dissolution of the Copper abounding in the Verdigrease, and therefore we
Conjectur'd, that if both the Verdigrease, and such Salts were dissolv'd in
fair Water, the small Parts of both being therein more subdivided, and set
at liberty, would have better access to each other, and thereby Incorporate
much the more suddenly; And accordingly we found, that if upon a strong
Solution of good French Verdigrease (for 't