Private correspondence with various persons on official business, including Capt Alexander Burnes, Sir Harford Jones Brydges, Sir Herbert Taylor, 13th Lord Elphinstone, Sir Charles Trevelyan
Private letters from Lord Palmerston chiefly on diplomatic affairs; also correspondence with him regarding an honour to be conferred on McNeill for his services in the Crimea Dated as: 1835-39; 1842; 1853; 1857
Private letters from Lord Auckland, Governor-General of India, relating to the diplomatic situation; also copy of one letter from McNeill to Auckland (Aug 1838) [McNeill's letter book see No. 19 below]
Copies of two letters from McNeill to William Cabell, Assistant Secretary and Senior Clerk in the Secret and Political Dept, Board of Control; letter from Sir John Cam Hobhouse, President of the Board, to McNeill
Translations of Persian correspondence, chiefly between McNeill and Hajji Mirza Aghasi, Prime Minister of Persia Dated as: (? 1831); (? 1835)-1836; 1838