'Roccella tinctoria' definitions:
Definition of 'Roccella tinctoria'
(from WordNet)
noun
A source of the dye archil and of litmus [syn: roccella, Roccella tinctoria]
Definition of 'Roccella tinctoria'
From: GCIDE
- Roccellic \Roc*cel"lic\, a. [F. roccellique, fr. roccelle archil, It. & NL. roccella, fr. It. rocca a rock, because archil grows on rock.] (Chem.) Pertaining to, or designating, a dibasic acid of the oxalic series found in archil (Roccella tinctoria, etc.), and other lichens, and extracted as a white crystalline substance C17H32O4. [1913 Webster]
Definition of 'Roccella tinctoria'
From: GCIDE
- Litmus \Lit"mus\, n. [D. lakmoes; lak lacker + moes a thick preparation of fruit, pap, prob. akin to E. meat: cf. G. lackmus. See Lac a resinous substance.] (Chem.) A dyestuff extracted from certain lichens ({Roccella tinctoria}, Lecanora tartarea, etc.), as a blue amorphous mass which consists of a compound of the alkaline carbonates with certain coloring matters related to orcin and orcein. [1913 Webster]
- Note: Litmus is used as a dye, and being turned red by acids and restored to its blue color by alkalies, is a common indicator or test for acidity and alkalinity. [1913 Webster]
- Litmus paper (Chem.), unsized paper saturated with blue or red litmus, -- used in testing for acids or alkalies. [1913 Webster]