1. Edinburgh University Library. Letters to Rev. James Brown from James Ivory, John, Leslie, and, Thomas, Chalmers, Dc.2.57.
2. British Library, London. Macvey Napier Correspondence.Add. MSS. 34,612. (a), J. Ivory, to MN: f. 272, 29 July and 22 Aug. 1819; (b) f. 283, 3 Sept. 1819; (c) f. 272, 22 Aug. 1819. (There are also many letters from John Leslie to MN in Add. MSS. 34611-34614.)
3. British Library, London, Charles Babbage Correspondence. (a) Add. MSS. 37184, David, Brewster, to CB: ff. 201–202, 3 Feb. 1829; (b) Add MSS 37185, David, Brewster, to CB: ff. 49–51, 12 Feb. 1830.
4. National Library of Scotland, Edinburgh. Black Papers: (a) MS 3713, John Leslie to Adam Black. Constable Papers: (b) MS 790, Letters to, John, Leslie. MS 331, John, Leslie, to Archibald Constable: (c) ff. 148, 150, 10 Sept. 1819; (d) ff. 167–178, Dec. 1824 - May 1825; (e) f. 180, 12 June 1825.
5. Royal Society of London. Correspondence of, Sir John, F. W. Herschel, John, Leslie, to JH: (a) HS.11.473, 20 Sept 1830. JH to William Wallace: (b) HS.20.226, Dec. 12 1825, (copybook).