Contractions. - Indig. Ind.
Indigofera tinctoria. Nat. ord., Leguminosae.
Habitat. - East Indies, middle regions of America, and tropical Africa.
Parts employed. - A peculiar dye-stuff obtained by oxidation of an infusion of the leaves and stems.
Characters. - The imported Indigo, if good, has the following characters: A dark blue colour, passing into violet-purple, void of taste and smell, but by rubbing with a smooth, hard substance it assumes the lustre and hue of copper. It floats in water. When burned it leaves very little residue. It is soluble in Sulphuric Acid, forming a deep blue solution; insoluble in water or ether. Its colour is not changed by alkalies.
Preparation. - Trituration.
Reference to Horn. Proving. - Noack and Trinks.
Proper forms for dispensing. - lx to 3, Trituration only. 4, dilute Tincture only. 5 and upwards, Tincture, Pilules, or Globules.