On reverse of a holograph letter dated 5 August 1700 from Newton to Catherine Barton [his half-niece], wishing her well with her recovery from smallpox.||The letter to Barton is very well represented in print, appearing in David Brewster, Memoirs of the Life, Writings, and Discoveries of Sir Isaac Newton (2 vols., Edinburgh, 1855), 2: 213, in Louis Trenchard More, Isaac Newton (New York and London, 1934), 470-1, in Craig, NATM, 27, in NC, 4: 349-50, and in Westfall, 595. It does not seem to have occurred to any of the authors or editors of these works that the fact that Newton used the same sheet for notes on coinage rather suggests he never sent the letter (though it is of course possible he sent another copy).||The manuscript is badly damaged and all the printed versions contain a number of conjectural readings.