Take one ounce of best Spanish indigo, finely powdered, and half a pound of oil of vitriol; put them in a bottle, and let them stand in the sun a week; shake it often, but do not cork it tight, lest it should burst the bottle; take four pounds of black-oak bark, and the same of hickory, shave them fine, and soak them till wet through; then boil them in ten gallons of water till all the color is extracted; when take out the chips, put in a pound of alum; shake the bottle of indigo and vitriol, and pour it in; let them boil together a few minutes, and put in the yarn; turn it over several times, and let it boil half an hour; then spread it out in the sun for about an hour, and wash it well in strong soap-suds through two waters, to keep it from becoming tender. This will color ten pounds of yarn. You may have a fine blue color by omitting the bark. It will not answer for any thing but wool or silk, as the vitriol will destroy linen or cotton.
Domestic Cookery, Useful Receipts, and Hints to Young Housekeepers.