litmus paper

American  

noun

1. a strip of paper impregnated with litmus, used as a chemical indicator.

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Etymology

Origin of litmus paper

First recorded in 1795–1805

Example Sentences

We did go to the newsstand at the Reading Terminal and try to buy a Litmus paper, but the agent didn't have any.

From Mince Pie by Morley, Christopher

Litmus paper all along the banks and nothing but ozone.

From Rolling Stones by Henry, O.

Litmus paper is not necessary when I determine a soil to be acid or alkali. 

From The Jacket (Star-Rover) by London, Jack

Litmus paper remained either red or blue when stuck into the jelly.

From The Water Eater by Marks, Winston K.

Litmus paper tests made all along the river show—but you can read it all in the prospectuses; or the Santonian will recite it for you, word by word.

From Rolling Stones by Henry, O.