ACACIA, EGYPTIAN THORN, or BINDING BEAN-TREE, in Botany, a species of mimosa, according to Linnaeus; though other botanists make it a distinct genus. See MIMOSA, BOTANY INDEX.
The flowers of a species of the acacia are used by the Chinese in making that yellow which we see bears washing in their silks and stuffs, and appears with so much elegance in their painting on paper. The method is this:
They gather the flowers before they are fully open; these they put into a clean earthen vessel over a gentle heat, and stir them continually about as they do the tea leaves, till they become dryish and of a yellow colour; then to half a pound of the flowers they add three spoonfuls of fair water, and after that a little more, till there is just enough to hold the flowers incorporated together; they boil this for some time, and the juice of the flowers mixing with the water, it becomes thick and yellow; they then take it from the fire, and strain it through a piece of coarse silk. To the liquor they add half an ounce of common alum, and an ounce of calcined oyster shells reduced to a fine powder. All is then well mixed together; and this is the fine lasting yellow they have so long used.
The dyers of large pieces use the flowers and seeds of the acacia for dying three different sorts of yellow. They roast the flowers, as before observed; and then mix the seeds with them, which must be gathered for this purpose when full ripe: by different admixture of these, they give the different shades of colour, only for the deepest of all they add a small quantity of Brazil wood.
Mr Geoffroy attributes the origin of bezoar to the feeds of this plant; which being bruised by certain animals, and vellicating the stomach by their great fumes and asstringency, cause a condensation of the juices, till at length they become coated over with a stony matter, which we call BEZOAR.
Fosse Acacia. See ROBINIA, BOTANY Index.
Three-thorned Acacia, or Honey-locust. See GLADITSIA, BOTANY Index.