them; and may ſerve to explain the Effects of thoſe vitriolic Waters which are ſaid to convert Iron into Copper. A Piece of Iron Wire dipped into any of theſe Solutions, and taken almoſt immediately out again, is ſeen covered with Copper ſo far as the Menſtruum has touched it; and by drawing the Fingers carefully over it, a fine thin Tube of pure Copper may be taken off from it: This may ſerve to ſhew us of what Kind the Menſtruum is which Nature uſes to produce the blue Vitriol from Copper, which in Solution has the ſame Effect; and proves that the Ziment or vitriolic Water, ſo famous for its ſuppoſed Virtue, of turning Iron into Copper, is no other than a blue Vitriol in a fluid State, becauſe ſuſpended in too large a Quantity of aqueous Matter; perhaps, indeed, containing Particles of many other Kinds, but evidently owing its characteriſtic Quality, to Particles of Copper, in a State very nearly reſembling that of blue Vitriol, though at preſent in Solution.
That the natural Colour of Solutions of Copper in the vitriolic Acids is blue, is evident from only leaving a Drop of any of them on a Plate of Copper, which is preſently covered with blue Cryſtals: And any one a little acquainted with Chemiſtry will know, that no Difference is to be expected in Solutions made with Oil of Sulphur from thoſe with Oil of Vitriol; for theſe Acids differ ſcarce ſenſibly when both well rectified, and indeed appear, on ſtrict Examination, to be really the ſame
