Acc.8594. Letter, 1804, to John Macdonald concerning his 'book on tactics'.
MS.1306 (passim). Letters, 1771, 1795, of and concerning John Macdonald.
MS.10782, folios 169-176. Letters, 1792-1793, 1795, of John Macdonald, Fort Marlbro, mostly concerning natural history.
MS.1694, page 105. Letter, 1810, of John Macdonald, Exeter, to Henry Stuart encouraging the intention of the latter to publish an account of the 'internal war of 1745'.
MS.17929, folio 13. Letter, 1822, of John Macdonald to the Reverend James Grant concerning music, Highland bagpipes and Flora Macdonald.
MS.14839, folios 268-269. Letter, 1825, of John Macdonald to the 2nd Viscount Melville concerning telegraphic science.
MS.2521, folio 134. Letter, 4th Jany [gap], of John Macdonald concerning a critical review of a work by him.
MS.8185. Manuscript, 1787, of John Macdonald, 'Practical tracts on artillery'.