Correspondents include Sir Charles's Dalrymple brothers and sisters, and his nephew, Sir Charles Fergusson, 7th Baronet of Kilkerran, with copies of letters written while serving in South Africa during the Boer War. There are also letters from members of the Boyle and Hunter-Blair families, in particular Sir David Oswald Hunter-Blair, 5th Baronet, of Dunskey, and Abbot of Fort Augustus.