rubiacicacid

Chem.: C32HO17. Produced, according to Schunck, by boiling rubiacin or rubiafin with ferric nitrate or chloride, and adding hydrochloric acid, which throws down impure rubiacic acid. It is purified by rep rec i pit at i on. The acid is obtained as a lemon-yellow amorphous powder, slightly soluble in boiling water, and reconverted into rubiacin by sulphuric acid. rû-bi-aç-in, s . [Eng. rubiac ( eœ ); -in ( Chem . ) .] Chem.: C32H22O10. Madder-orange. A yellow coloring matter, discovered by Runge in madder root. It crystallizes in light yellow plates or needles having a strong reddish green luster, slightly soluble in boiling water, but very soluble in boiling alcohol. It di olves in sulphuric acid, forming a yellow liquid, and in alkalies forming purple solutions. It is of little use as a dye, a piece of mordanted calico being scarcely colored by it.