India:an indigo plantation, an overseer looking on, as others work picking indigo plants and processing them. Engraving, 1778.

"Indostan, or India proper … Among other fine and valuable trees here, is the indigo tree, or shrub, which is about the size of a rose-tree, but has a smooth rind. The leaves, when stripped off at the proper season, are laid together, when a vegetable dew exhales from them. They are then immersed in water, contained in vessels adapted for the purpose. After the water bath extracted the blue from the leaves. it is drained off: the sediment is then exposed in broad shallow vessels to the sun beams, through the heat of which the moisture evaporates, and the indigo itself remains in cakes at the bottom."--Middleton, loc. cit.