also to be understood in most of these Experiments, if no Circumstance of them argue otherwise) Spirit of Salt either made no considerable Change, or alter’d the Colour but from a Darker to a Lighter Red.  How it will succeed in many other Vegetable Juices, and Infusions of the same Colour, I have at present so few at hand, that I must leave you to find it out your self.  But as for the Operation of the other sorts of Salts upon these Red Substances, I found it not very Uniform, some Red, or Reddish Infusions, as of Roses, being turn’d thereby into a dirty Colour, but yet inclining to Green.  Nor was the Syrrup of Clove-july-flowers turn’d by the solution of Pot-ashes to a much better, though somewhat a Greener, Colour.  Another sort of Red Infusions was by an Alcaly not turn’d into a Green, but advanc’d into a Crimson, as I shall have occasion to note ere long.  But there were other sorts, as particularly the lovely Colour’d juice of Buckthorn Berries, that readily pass’d into a lovely Green.

EXPERIMENT XXVII.

Among other Vegetables, which we thought likely to afford Exceptions to the General Observation about the differing Changes of Colours produc’d by Acid and Sulphureous Salts, we thought fit to make Trial upon the Flowers of Jasmin, they being both White as to Colour, and esteem’d to be of a more Oyly nature than other Flowers.  Whereupon having taken the White parts only of the Flowers, and rubb’d them somewhat hard with my Finger upon a piece of clean Paper, it appear’d very little Discolour’d.  Nor had Spirit of Salt, wherewith I moisten’d one part of it, any considerable Operation upon it.  But Spirit of Urine, and somewhat more effectually a strong Alcalizate Solution, did immediately turn the almost Colourless Paper moisten’d by the Juice of the Jasmin, not as those Liquors are wont to do, when put upon the Juices of other Flowers, of a good Green, but of a Deep, though somewhat Greenish Yellow, which Experiment I did afterwards at several times repeat with the like success.  But it seems not that a great degree of Unctuousness is necessary to the Production of the like Effects, for when we try’d the Experiment with the Leaves of those purely White Flowers that appear about the end of Winter, and are commonly call’d Snow drops, the event, was not much unlike that, which, we have been newly mentioning.

EXPERIMENT XXVIII.

Another sort of Instances to show, how much changes of Colour effected by Salts, depend upon the particular Texture of the Colour’d Bodies, has been afforded me by several Yellow Flowers, and other Vegetables, as Mary-gold Leaves, early Prim-roses, fresh Madder, &c.  For being rubb’d upon White Paper, till they imbued it with their Colour, I found not, that by the addition of Alcalizate Liquors, nor yet by that of an Urinous Spirit, they would be turn’d either Green or Red:  nor did so Acid a Spirit, as that of Salt, considerably alter their Colour,