“Litmus” is a dyed in the moss Norse word

Words about words


Photo: Kanesskong / Wikimedia Commons
Blue and red litmus papers.

M. Michael Brady
Asker, Norway

Litmus is the name of a blue coloring matter obtained from certain species of fungus, particularly Roccella tinctoria, which was first described in 1805. In acid solution, it turns red; in alkaline solution, it turns blue. Strips of litmus paper are extensively used to indicate the acidity or alkalinity of liquids.

The word litmus comes from the Old Norse litmosi, literally “dye-moss,” as lit means color and mosi means moss. The equivalent modern Norwegian word is lakmus, most likely because it linguistically traveled in time via the middle Dutch leechmos to the modern Dutch lakmoes and hence to the Norwegian lakmus.

Read more: www.etymonline.com/word/litmus

This article originally appeared in the April 5, 2019, issue of The Norwegian American.

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M. Michael Brady

M. Michael Brady was born, raised, and educated as a scientist in the United States. After relocating to the Oslo area, he turned to writing and translating. In Norway, he is now classified as a bilingual dual national.