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Webster 1913 Edition
Litmus
Lit′mus
,Noun.
[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. ☞ 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.
Litmus paper
(Chem.)
, unsized paper saturated with blue or red litmus, – used in testing for acids or alkalies.
Webster 1828 Edition
Litmus
LIT'MUS
,Definition 2024
litmus
litmus
English
Noun
litmus (countable and uncountable, plural litmuses)
- (uncountable) A dyestuff extracted from certain lichens, that changes color when exposed to pH levels greater than or less than certain critical levels.
- A simple test of acidity in a liquid using litmus, usually in the form of litmus paper.
- A simple test of any attribute; a litmus test.
Synonyms
- (dyestuff from lichen): lacmus
Derived terms
Translations
dyestuff from lichen