Origin of litmus
Examples from the Web for litmus
But when did they become the litmus test of competence in office?
So they are a litmus paper for wider fertility—not a significant driver of Israeli birthrates.
Opposition to the Affordable Care Act in toto might linger as a litmus test for conservatives.
The right-wing base and media will make it a litmus test issue.
The Veterans of Foreign Wars organized an Americanization committee that promoted the song as a litmus test of loyalty.Star-Spangled Confederates: How Southern Sympathizers Decided Our National Anthem|Jefferson Morley|July 4, 2013|DAILY BEAST
It is not perfectly soluble in water; and does not turn the colour of litmus red.
Tincture or solution of litmus, or an alkaline solution of indigo.
Agar plates, litmus, glucose broth and a sheet of clean paper were at the same time exposed in the box.Handbook of Medical Entomology|William Albert Riley
Both the gas and its aqueous solution exercise a feebly acid reaction on litmus.
It is therefore important to control the addition of milk of lime by the use of litmus paper.
British Dictionary definitions for litmus
Word Origin for litmus
Word Origin and History for litmus
"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.
Medicine definitions for litmus
Science definitions for litmus
Culture definitions for litmus
In chemistry, a kind of paper used to tell whether a solution is an acid or a base. Acids turn blue litmus paper red; bases turn red litmus paper blue. Other testing paper or sophisticated instruments can be used to measure the pH of a solution more precisely.