CHAP. 27.—INDICUM.
Next in esteem to this is indicum,[1] a production of India,
being a slime[2] which adheres to the scum upon the reeds there.
When powdered, it is black in appearance, but when diluted in
water it yields a marvellous combination of purple and cæruleum.
There is another[3] kind, also, which floats upon the surface
of the pans in the purple dye-houses, being the scum
which rises upon the purple dye. Persons who adulterate it,
stain pigeons' dung with genuine indicum, or else colour Selinusian[4]
earth, or anularian[5] chalk with woad.
The proper way of testing indicum is by laying it on hot
coals, that which is genuine producing a fine purple flame,
and emitting a smell like that of sea-water while it smokes:
hence it is that some are of opinion that it is gathered from the
rocks on the sea-shore. The price of indicum is twenty denarii
per pound. Used medicinally, it alleviates cold shiverings
and defluxions, and acts as a desiccative upon sores.
1. Indigo, no doubt, is the colour meant. See B. xxxiii. c. 57.
2. It is the produce of the Indigofera tinctoria, and comes from Bengal
more particularly. Beckmann and Dr. Bancroft have each investigated this
subject at great length, and though Pliny is greatly mistaken as to the mode in which the drug was produced, they agree in the conclusion that
his "indicum" was real indigo, and not, as some have supposed, a pigment
prepared from isatis, or woad.
3. This passage, similar in many respects to the account given by Dioscorides, is commented on at great length by Beckmann, Hist. Inv. Vol. II.
p. 263. Bohn's Edition.
4. See Chapter 56 of this Book.
5. See Chapter 30 of this Book.