An encyclopedia article on indigo from Rees's Cyclopaedia (1819). It covers the history and naming of the dye, the cultivation of the indigo plant, and the fermentation, beating, settling, drying and packing of indigo, followed by its use in dyeing blue (alkaline and urine vats), calico printing and other trades. It also describes two indigo-grinding mills with figure references, and a short botanical entry on the genus Indigofera.