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EXPERIMENT XXII.
ITalian Painters being us'd to imitate Ʋlira∣marine Azure, by grinding Virdigrease with Sal Armoniack, and leaving it to rot in a Dunghil; This gave us a hint to pour Oyl of Tartar upon a Solution of Verdigrease; which, tho' at first, the Mixture was turbid, yet being settl'd, it produc'd a lovely Tincture; and a Lixivium of Pot-ashes, being made use of in∣stead of this Oyl, it yielded an Azure some∣thing Paler than the former; and if Spirit of Harts-horn be made use of instead of these, a greater variety of ceruleous Liquors may be obtain'd. The better way to separate these Azure Liquors from their Feces, is by Decentation, than Filtration, the Lquor being, by the latter means usually stain'd.