That mass of blue colour which the Spaniards call añil, or añir, and
other Europeans, indigo, is made of a plant, with a long slender root,
branching out into a number of shoots; on which account its long stalks
partly creep on the ground, and partly stand upright. They are red on
one side, and are loaden with small boughs, and round leaves, about the
size of one's little finger nail, of a dark green, on one side, and a
silvery white on the other. The little blossoms of this plant are of a
palish red, with flowers like a husk of corn, or as others explain it,
like an open helmet: and are succeeded by pods, hanging from the stalk,
full of an olive-coloured seed, very like rape seed. The leaves of the
plant, when perfectly mature, are gathered in bundles, pounded in stone
mortars in the first place, and next steeped, and turned about in a pan
of tepid, or as others say, cold water. They use them poured out on a
wooden table, surrounded with a high wooden brim, and hollowed here and
there into ditches. After the water has escaped, the thicker part of the
colour settles into those ditches, coagulates, and hardens. The solid
particles are then taken out, and dried for many days; for the dryer
they are, the nearer they approach to that colour which we call Venetian
blue. Those who dyed webs, or garments with that colour in Paraguay,
mixed children's urine, instead of alum, with it, to prevent the colour
from flying. The plant añil is sown in other places, and grows
spontaneously in the plains of Paraguay, but is generally neglected, the
industry of the inhabitants seldom answering to the liberality of
nature. I never had the least doubt but this plant might be cultivated
in those countries of Europe where the climate is milder. The seed must
be sown in a soft, and well-tilled soil. The young plants must be
removed, like lettuce, and cabbage, and placed at proper distances:
great care must likewise be taken to prevent their being choked with
weeds.