To Dye Cotton Blue

Boil a pound of chipped logwood in water enough to cover the cotton; take out half a gallon, and dissolve in it an ounce of verdigris, and one of alum; boil the yarn in the logwood water an hour, stirring it, and keeping it loose; then take it out, and mix in the verdigris; put back the yarn, and let it boil four hours, stir all the time, and take it out every hour to give it air, dry it in the sun, and the next day boil it in soap-suds. This will dye six pounds of cotton a deep blue. After it is done, you may put in as much more, and it will dye a pale blue.