sympathetic ink

American  

[sim-puh-thet-ik ingk] / ˌsɪm pəˈθɛt ɪk ˈɪŋk /

noun

1. invisible ink.

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sympathetic ink British  

noun

1. another term for invisible ink

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Etymology

Origin of sympathetic ink

First recorded in 1715–25

Example Sentences

See Examples For:

sympathetic ink

Cobalt, dissolved in aqua regia, makes an excellent sympathetic ink, appearing green when held to the fire, and disappearing when cold, unless it has been heated too much, when it burns the paper.

From Heads of Lectures on a Course of Experimental Philosophy: Particularly Including Chemistry by Priestley, Joseph

By way of variation the chosen word may be produced with the sympathetic ink, or it may be revealed by the method employed in "A New Postal Trick."

From Magic In which are given clear and concise explanations of all the well-known illusions as well as many new ones. by Stanton, Ellis

Your highness," returned the courier, "the dispatches are secret, and written with sympathetic ink.

From Prince Eugene and His Times by Mühlbach, L. (Luise)

But this was only a blind; the real letters were written in cipher, with sympathetic ink.

From Mr. Fortescue An Andean Romance by Westall, William

Might there not be something written in sympathetic ink?

From The Naval History of the United States Volume 1 by Abbot, Willis J. (Willis John)