Experiment X.
That a Solution of Silver does Dye Hair of a Black Colour, is a Known Experiment, which some persons more Curious than Dextrous, have so Unluckily made upon themselves as to make their Friends very Merry. And I remember that the other day, I made my self some Sport by an Improvement of this Observation, for having dissolv’d some Pure Silver in Aqua Fortis, and Evaporated the Menstruum ad siccitatem, as they speak, I caus’d a Quantity of fair Water to be pour’d upon the Calx two or three several times, and to be at each Evaporated, till the Calx was very Drye, and all the Greenish Blewness that is wont to appear in Common Crystals of Silver, was quite carry’d away. Then I made those I meant to Deceive, Moisten some part of their Skin with their own Spittle, and slightly Rub the moistned parts with a little of this Prepar’d Silver, Whereupon they Admir’d to see, that a Snow-white Body laid upon the White Skin should presently produce a deep Blackness, as if the stains had been made with Ink, especially considering that this Blackness could not, like that produc’d by ordinary Ink, be readily Wash’d off, but requir’d many Hours, and part of it some dayes to its Obliteration. And with the same White Calx and a little Fair Water we likewise Stain’d the White Hafts of Knives, with a lasting Black in those parts where the Calx was Plentifully enough laid on, for where it was laid on but very Thinly, the Stain was not quite of so Deep a Colour.