a. - Pertaining to, or designating, a complex red dyestuff
(called rosolic acid) which is analogous to rosaniline and aurin. It is
produced by oxidizing a mixture of phenol and cresol, as a dark red
amorphous mass, C20H16O3, which forms weak salts with bases, and stable
ones with acids. Called also methyl aurin, and, formerly, corallin.