James Boswell died in 1795 believing he had touched and kissed a cache of Shakespeare's original letters and papers discovered by a Mr. Ireland. His friend, Edmond Malone, publicly exposed the lot as a forgery just a year later.
Archibald StewartBorn 1697
Son of Sir Robert Steuart (1643-1707), 1st of Allanbank, and Helen Cockburn. Provost (1744-1745) of and MP for Edinburgh at the time of the Jacobite rebellion in 1745. He refused to arm the city, making it possible for the Jacobite Highland army to occupy the city. In 1747 he was tried for neglect of duty and misbehaviour in the execution of his office. He was acquitted. David Hume wrote a 51p pamphlet in his defence.
Life with Boswell:
Boswell mentions him being present at a dinner party at John Trotter's on May 19, 1763.
Several writings were published concerning Stewart's trial in 1747, and a search on the AbeBooks.com used books search engine for The Trial of Archibald Stewart, should amount to some relevant hits. Sometimes it is even possible to find original copies of David Hume's A True Account of the Behaviour and Conduct of Archibald Stewart.