Menstruum will work no farther on it, becomes exceeding White, but as we elsewhere note, does very easily of it self acquire the consistence, not of a Metalline Calx, but of a Coagulated matter, which we have observ’d with pleasure to look so like, either to curdled Milk, or curdled Whites of Eggs, that a person unacquainted with such Solutions may easily be mistaken in it.  But when I purposely prepar’d a Menstruum that would dissolve it as Aqua-fortis dissolves Silver, and not barely Corrode it, and quickly let it fall again, I remember not that I took notice of any particular Colour in the Solution, as if the more Whitish Metalls did not much Tinge their Menstruums, though the conspicuously Colour’d Metalls as Gold, and Copper, do.  For Lead dissolv’d in Spirit of Vinegar or Aqua-fortis gives a Solution cleer enough, and if the Menstruum be abstracted appears either Diaphanous or White.  Of the Colour of Iron we have elsewhere said something:  And ’tis worth noting, that though if that Metall be dissolv’d in oyl of Vitriol diluted with water, it affords a Salt or Magistery so like in colour, as well as some other Qualities, to other green Vitriol, that Chymists do not improperly call it Vitriolum Martis; yet I have purposely try’d, that, by changing the Menstruum, and pouring upon the filings of Steel, instead of oyl of Vitriol, Aqua Fortis, (whereof as I remember, I us’d 4 parts to one of the Metall) I obtain’d not a Green, but a Saffron Colour Solution; or rather a thick Liquor of a deep but yellowish Red.  Common Silver, such as is to be met with in Coines, being dissolv’d in Aqua fortis, yields a Solution tincted like that of Copper, which is not to be wondred at, because in the coining of Silver, they are wont (as we elsewhere particularly inform you) to give it an Allay of Copper, and that which is sold in shops for refined silver, is not (so far as we have tryed) so perfectly free from that ignobler Metall, but that a Solution of It in Aqua fortis, will give a Venereal Tincture to the Menstruum.  But we could not observe upon the solution of some Silver, which was perfectly refin’d, (such as some that we have, from which 8 or 10 times its weight of Lead has been blown off) that the Menstruum though held against the Light in a Crystal Vial did manifestly disclose any Tincture, only it seem’d sometimes not to be quite destitute of a little, but very faint Blewishness.

But here I must take notice, that of all the Metalls, there is not any which doth so easily and constantly disclose its unobvious colour as Copper doth.  For not only in acid Menstruums as Aqua Fortis and Spirit of Vinegar, it gives a Blewish green solution, but if it be almost any way corroded, it appears of one of those two colours, as may be observ’d in Verdigreese made several wayes, in that odd preparation of Venus, which we elsewhere teach you to make