6
The French way of dying Yellow Silk.
First, alum your silks half an hour in cold ⟨alum⟩ liquor, then wash them. Pass them through a pan ⟨of⟩ weld liquor, at a hard heat. If they are to be of lemon yellow, dissolve a trifling quantity of blue vitriol in your pan to the colour required.
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Sympathetic Ink.
Dissolve bismuth in nitrous acid: when the writing with this fluid is exposed to the vapour of liver of sulphur, it will become quite black.
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Black Ink.
Take of Aleppo galls, in coarse powder. 8 oz; logwood in thin chips, 4 oz; copperas 4 oz; gum ⟨arabic⟩ finely powdered, 3 oz; blue vitriol, 1 oz.; sugar candy 1 oz. Boil the galls and logwood together in twelve pints of rain water for one hour; strain the decoctic and then add the other ingredients; stir the mixture until the whole be dissolved, more especially the ⟨gum⟩ and then let it subside for twenty-four hours; lastly decant the ink very steadily, and cork it in stone ⟨bottles⟩ for use.
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Red Ink.
Boil an ounce of fine Brazil wood (in the chips) ⟨and⟩ half a pint of water, and add three drachms of gum arabic, with half an ounce of alum.
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Blue Ink.
Dissolve a small quantity of indigo in a little oil vitriol, then add a sufficient quantity of water, in which is dissolved some gum arabic.
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