Page:Theophrastus - History of Stones - Hill (1774).djvu/356

 been prepared from: For all thee fixed Alkalies of Plants may be reolved into a bitter aline Subtance, a tronger fixed Alkali, and a pure imple Earth; and in the Operation there will a mall Quantity of an oily Matter always be dicovered.

Of the volatile Alkalies, Spirit of Sal Armoniac, Spirit of Urine, and Spirit of Harthorn, all afford Solutions of Copper of the mot beautiful and vivid celetial Blue: This is of different Degrees, according to the different Quantity of the Metal diolved; but in equal Proportions, and with the Spirits of equal Strength, the Colour is exactly the ame in them all. The volatile Alkalies have in their Operations on this Metal, therefore, a great Analogy to the fixed. Thee Mentruums conit only of a very fine, ubtle, volatile, alkaline Salt, upended in a mall Quantity of Water, which has no Share in extracting this glorious Colour; for the dry volatile Salts of the ame Subtances, mixed with Copper Filings, and corked up in a Vial together, acquire, in a Day or two, the very ame 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-alt, of a pale whitih Green: Of thee, the Sal Armoniac diolves it the oonet, the Sea-alt takes more Time, and the Borax is lowet of all. The ret of the Solutions alo mentioned here, require different Time and different Methods to produce them; the Spirit