Kinds of Aqua regia; Silver, in Aqua fortis, but not in Agua regia, or Spirit of Salt, or Oil of Vitriol, or, in ſhort, in any but the nitrous Acids: whence it may very properly be ſaid, that Sea-ſalt is the true Diſſolvent of Gold, and Nitre of Silver. Lead is readily diſſolved by the weaker Acids, but not at all by Agua regia, and but difficultly by many of the ſtronger; Iron by moſt of the acid Salts; and Tin by Aqua regia, and not eaſily by any other Menſtruum, unleſs firſt diveſted of its Sulphur by Calcination; but Copper is to be diſſolved by every Kind of Salt; and, in ſhort, by almoſt every thing that ever had in Chemiſtry the Name of a Menſtruum; and produces, with its different Solvents, an almoſt infinite Variety of very beautiful Colours: So that it may indeed have been the Baſis of the Colour of, perhaps, more of the Gems than has yet been imagined.
Filings of Copper dropt into the Flame of a Lamp, thrown into an horizontal Direction by a Blow-pipe, emit a very beautiful green Flame.
Mixed with three Times their Quantity of corroſive Sublimate, and afterwards diveſted of the Mercury by Fire, they form, with the remaining Salts, a tranſparent Reſin of a beautiful Hyacinth Colour, which will melt and burn in the Fire, emitting alſo a fine green Flame.
Expoſed to the Fumes of Quickſilver, they become white and ſhining like Silver.
Melted
