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 made in the ame Proportions: And the Spirit of Verdigreae may very naturally excel both, as it is the tronget vegetable Acid that Art can any way produce; though it is truly no other than a Vinegar aborbed by Copper, and afterwards driven from it again by the Force of Fire; little altered, except as rendered more pure. It is remarkable, that Copper will thus part with this Acid in its proper and natural Form; whereas no other Metal will; for Iron and Lead, the only other Metals that will admit this Acid, alter it in the Mixture from its original Nature; for it can never be produced from them again in its natural State, but is in both Caes quite a different Thing: When eparated from Lead, it appears in Form of an oily fat Liquor; and from Iron, little other than inipid Water. The Spirit of Verdigreae is, however, the trongeft of all vegetable Acids; and accordingly, extracts from Copper the Colour nearet approaching to that of the Solutions of that Metal in ome of the trongeft mineral Acids.

Of the fixed Alkalies, Salt of Wormwood, Potahes, and Oil of Tartar per deliquium, all afford Solutions of Copper of a glorious, deep, celetial Blue, and no way ditinguihable from one another, if the Solutions are made in exact Proportions. An Ærugo, of a greenih Colour, is indeed producible on Copper by thee Mentruums; and a mall Quantity of a imilar Subtance is ometimes found wimming on the Surface of thee very Solutions: But this is