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, ſave that it ſeem’d a little to Dilute it. Only in ſome early Prim-roſes it deſtroy’d the greateſt part of the Colour, and made the Paper almoſt White agen. And Madder alſo afforded ſome thing peculiar, and very differing from what we have newly mention’d: For having gather’d Some Roots of it, and, (whilſt they were recent) expreſs’d upon White Paper the Yellow Juice, an Alcalizate Solution drop’d upon it did not turn it either Green or White, but Red. And the bruis’d Madder it ſelf being drench’d with the like Alcalizate Solution, exchang’d alſo its Yellowiſhneſs for a Redneſs.
An admonition touching the four preceding Experiments.
Having thus (Pyrophilus) given you divers Inſtances, to countenance the General obſervation deliver’d in the twenty fifth Experiment, and divers Exceptions whereby it ought to be Limited; I muſt leave the further Inquiry into theſe Matters to your own Induſtry. For not remembring at preſent many of thoſe other Trials, long ſince made to ſatisfie my ſelf about Particulars, and not having now the Opportunity to repeat them, I muſt content my Self to have given you the Hint, and the ways of proſecuting the ſearch your Self; and only declare to you in general, that, As I have made many Trials, unmention’d in this Treatiſe, whoſe Events were agreeable to thoſe mention’d in the twenty fifth Experiment, ſo (to name now no other Inſtances) what I have try’d with Acid and Sulphureous Salts upon the Pulp of Juniper Berries, rubb’d upon White Paper, inclines me to think, That among that vaſt Multitude, and ſtrange Variety of Plants that adorn the face of the Earth, perhaps many other Vegetables may be found, on which ſuch Menſtruums may not have ſuch Operations, as upon the Juice of Violets, Peaſe-bloſſoms, &c. no nor upon any of thoſe three other ſorts of Vegetables, that I have taken notice of in the three fore-going Experiments. It ſufficiently appearing ev’n by theſe, that the effects of a Salt upon the Juices of particular Vegetables do very much depend upon their particular Textures.