Page:Theophrastus - History of Stones - Hill (1774).djvu/346

 Kinds of Aqua regia; Silver, in Aqua fortis, but not in Agua regia, or Spirit of Salt, or Oil of Vitriol, or, in hort, in any but the nitrous Acids: whence it may very properly be aid, that Sea-alt is the true Diolvent of Gold, and Nitre of Silver. Lead is readily diolved by the weaker Acids, but not at all by Agua regia, and but difficultly by many of the tronger; Iron by mot of the acid Salts; and Tin by Aqua regia, and not eaily by any other Mentruum, unles firt diveted of its Sulphur by Calcination; but Copper is to be diolved by every Kind of Salt; and, in hort, by almot every thing that ever had in Chemitry the Name of a Mentruum; and produces, with its different Solvents, an almot infinite Variety of very beautiful Colours: So that it may indeed have been the Bais 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 corroive Sublimate, and afterwards diveted of the Mercury by Fire, they form, with the remaining Salts, a tranparent Rein of a beautiful Hyacinth Colour, which will melt and burn in the Fire, emitting alo a fine green Flame.

Expoed to the Fumes of Quickilver, they become white and hining like Silver. Melted