Page:Theophrastus - History of Stones - Hill (1774).djvu/357

 Spirit of Nitre diolves the Metal almot intantaneouly, Agua fortis is nearly as quick in its Operation, and Agua regia requires only a little Time: But of the others, ome require long and tedious Procees, and others act bet, or perhaps only, by Vapour; and one of thee Procees hews, that where Mr. Boyle ays, he knew a Mentruum which by its Vapour would diolve a certain Metal, though it would carce work on it at all in Subtance; he is only talking of Copper and Vinegar. Sal Armoniac, it is to be alo oberved, affords us another Intance whence Nature may be upplied with a Mentruum for giving a blue Solution of Copper; ince, tho' the Sal Armoniac common among us now is factitious, there is no Quetion but that there is, and ever has been, a true native Sal Armoniac; and there needs no more than Copper diolved in Water impregnated with it, to give the different Blues of all the deepet Sapphires in the World; it being mot eay to procure a Solution of Copper of any Degree of Blue, only from a Solution of this Salt in Water, digeted for a few Days on Filings of that Metal.

Nature therefore is not tied to one Mentruum for the producing Blue from Copper; and that but a very carce and uncertain one: Since it is evident, that the Bodies neceary to give it are many; and thoe, many of them, common and every where abundant. That the common and univeral mineral Acid, o abundant every where in all the Kinds of Pyrites, the