- litmus: see moss
- litmus (n.)
- "blue dye-stuff obtained from certain lichens," early 14c., from Middle Dutch lijkmoes (Dutch lakmoes), from lac (see lac) + moes "pulp." Another theory is that it represents Old Norse litmose, literally "lichen for dying," from Old Norse lita "to dye, to stain," from litr "color, dye" (see lit (n.1)) + mos "moss." Yet another idea connects the first element to Middle Dutch leken "to drip, leak" (see leak (v.)).
Whichever was the original word, it probably was influenced by the others. The dye is obtained from certain lichens. It is naturally blue but turns red in acid and is restored to blue by alkalis. Figurative use of litmus test is first attested 1957, from scientific use of litmus-treated paper as a chemical indicator. Litmus paper with this meaning is from 1803.
- 1. The success of wind power represents a litmus test for renewable energy.
- 2. The outcome will be seen as a litmus test of government concern for conservation issues.
- 3. Ending the fighting must be the absolute priority, the litmus test of the agreements' validity.
- 4. Litmus paper can be used as an indicator of the presence of acid in a solution.
- 5. Her litmus test for good breeding is whether you split infinitives.
[ litmus 造句 ]