Ke Alakai o Hawaii, Volume VI, Number 11, 13 July 1933 — ASPIRIN MAKES SECRET INK [ARTICLE]

ASPIRIN MAKES SECRET INK

'German r,rtsoners during the wwlil War sent ovi censored letters whleh were later found to cdntain valuable information not tō the censors. The prtecmerB had no chemicals or tnvlMble' lnks avallable, and it wkd i*<*r&ile<ī recently that the secret lay in aspirin tablets to whieh the Qermans had access. When disso!ved in water, aspixin makee aa ink invisible to the e;e but when plaeed under a violetIVf light, the words show up piainly.