The Note I spoke off is this. [One Grain of _Cochineel_ dissolv'd in a
pretty Quantity of Spirit of Urine, and then dissolv'd further by degrees
in fair Water, imparted a discernable, though but a very faint Colour, to
about six Glass-fulls of Water, each of them containing about forty three
Ounces and an half, which amounts to above a hundred twenty five thousand
times its own Weight.]
_EXPERIMENT XXV._
It may afford a considerable Hint (_Pyrophilus_) to him, that would improve
the Art of Dying, to know what change of Colours may be produc'd by the
three several sorts of Salts already often mention'd, (some or other of
which may be procur'd in Quantity at reasonable Rates) in the Juices,
Decoctions, Infusions, and (in a word) the more soluble parts of
Vegetables. And, though the design of this Discourse be the Improvement of
Knowledge, not of Trades: yet thus much I shall not scruple to intimate
here, That the Blew Liquors, mention'd in the twentieth and one and
twentieth Experiments, are far from being the only Vegetable Substances,
upon which Acid, Urinous, and Alcalizate Salts have the like Operations to
those recited in those two Experiments. For Ripe _Privet Berries_ (for
instance) being crush'd upon White Paper, though they stain it with a
Purplish Colour, yet if we let fall on some part of it two or three drops
of Spirit of Salt, and on the other part a little more of the Strong
Solution of Pot-ashes, the former Liquor immediately turn'd that part of
the Thick juice or Pulp, on which it fell, into a lovely Red, and the
latter turn'd the other part of it into a delightfull Green.
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