Material collected by Leigh concerning Jean-Jacques Rousseau.
[1-12] Miscellaneous letters and papers, including observations on Rousseau's death, 1749-1778.
 'Romilly's cahier', copies of letters from Rousseau to the Marquis de Mirabeau, 1763-1773, made by Sir Samuel Romilly from originals lent by the Count de Mirabeau, with some additional letters.
[15-17] Correspondence between Denis Diderot and Charles Burney, 1771.
[18-22] Miscellaneous letters, a Revolutionary card and an eighteenth-century playing card.
 Leigh's file of correspondence and papers on buying and selling Rousseau letters, 1964-1972.