been prepared from: For all theſe fixed Alkalies of Plants may be reſolved into a bitter ſaline Subſtance, a ſtronger fixed Alkali, and a pure ſimple Earth; and in the Operation there will a ſmall Quantity of an oily Matter always be diſcovered.
Of the volatile Alkalies, Spirit of Sal Armoniac, Spirit of Urine, and Spirit of Hartſhorn, all afford Solutions of Copper of the moſt beautiful and vivid celeſtial Blue: This is of different Degrees, according to the different Quantity of the Metal diſſolved; but in equal Proportions, and with the Spirits of equal Strength, the Colour is exactly the ſame in them all. The volatile Alkalies have in their Operations on this Metal, therefore, a great Analogy to the fixed. Theſe Menſtruums conſiſt only of a very fine, ſubtle, volatile, alkaline Salt, ſuſpended in a ſmall Quantity of Water, which has no Share in extracting this glorious Colour; for the dry volatile Salts of the ſame Subſtances, mixed with Copper Filings, and corked up in a Vial together, acquire, in a Day or two, the very ſame Colour.
Of the neutral Salts, a Solution of Copper with crude Sal Armoniac, is of a glorious Blue; with native Borax, of a fine deep Green; and with Sea-ſalt, of a pale whitiſh Green: Of theſe, the Sal Armoniac diſſolves it the ſooneſt, the Sea-ſalt takes more Time, and the Borax is ſloweſt of all. The reſt of the Solutions alſo mentioned here, require different Time and different Methods to produce them; the
