The Collaborative International Dictionary of English v.0.48:
Rumicin \Ru"mi*cin\, n. (Chem.)
A yellow crystalline substance found in the root of yellow
dock (Rumex crispus) and identical with chrysophanic
acid.
[1913 Webster]
The Collaborative International Dictionary of English v.0.48:
Chrysophanic \Chrys`o*phan"ic\, a.
Pertaining to, or derived from, or resembling, chrysophane.
[1913 Webster]
Chrysophanic acid (Chem.), a yellow crystalline substance
extracted from rhubarb, yellow dock, sienna, chrysarobin,
etc., and shown to be a derivative of an anthracene. It is
used in the treatment of skin diseases; -- called also
rhein, rheic acid, rhubarbarin, etc.
[1913 Webster]