Dissolve some indigo in oil of vitriol for twenty-four hours, put a
couple of spoonfuls in your pot, add a little crystal of tartar, put in
your hackles and boil, or at least keep them at a scalding heat, or the
vitriol will burn the feathers, furs, &c., take them out, rinse them
well, and the colour will be lasting.
If to the above liquor some fustic chips, well boiled by themselves, and
the juice added, you may then have any shade of the best green.