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copper: the inks prepared from these mixture? were notequal to those made with the green vitriol only. I triedalso another preparation of copper, verdegris : a smalladdition of this made the colour of the ink remarkablydeeper on first writing, but this additional blackness didnot stand, and. the colour turned rusty much sooner thanwhen no verdegris was used. The effect of this ingre-dient will be further considered in the next section.

In some receipts for ink, the galls are directed not to bepowdered, but only bruised, or broken into three or fourpieces. To fee if this precaution could be of any advan-tage, I cut some galls into four pieces each, and some intobits like large pins heads : another parcel was reducedinto pretty fine powder. Equal weights of the threewere digested for a fortnight, with vitriol and water inequal proportions: the ink from the large pieces wasconsiderably paler than the other two, and that from thepowdered galls was the deepest coloured.

A small wooden calk, or a stone bottle, is commonlychosen for making ink in, and the vessel is generally keptstopt. As air appears to contribute to the deepening ofthe colour of ink upon paper, the characters not acquiringtheir full blackness till a day or two after writing, itseemed probable, that a free admission of air might havea like effect upon the ink in its fluid state, and conse-quently that a broad shallow open vessel, and frequentstirring, so as to expose fresh surfaces to the air, wouldcontribute to improve the colour, and make the ink flowblack from the pen. Accordingly mixtures of galls andvitriol with different proportions of water, were exposedto the air in flat stone-ware dishes, and stirred nine or tentimes a day for a month. The liquors wrote blackerthan those made from the fame quantities of the in-gredients in close vessels; but whether the difference

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