C7H7NO3

1 definition found

From The Collaborative International Dictionary of English v.0.48 [gcide]:

  Orcein \Or"ce*in\, n. (Chem.)
     A reddish brown amorphous dyestuff, {C7H7NO3}, obtained from
     orcin, and forming the essential coloring matter of cudbear
     and archil. It is closely related to litmus.
     [1913 Webster]