1Thomas Jefferson to James Jay, 7 April 1809 (Jefferson Papers)
...American Revolution he used an invisible ink of his own invention to pass on intelligence...
2To James Madison from James Jay, 1 July 1811 (Madison Papers)
...the use by the Continental Congress of an invisible ink he had invented. As secretary of...
3From John Jay to Peter Augustus Jay, 30 March 1813 (Jay Papers)
...“when he first sent me some of his invisible Ink?” tell him that I cannot recollect the...