Letters mostly to Clark, with some to his wife Frances Clark (d.1908), Adam Sedgwick (1785-1873) and others, mainly routine in nature, and collected for their autograph value. Another volume, containing letters of scientists, was not acquired.
MS.Add.8952 'Political' (116 letters)
MS.Add.8953 'Bishops etc.' (100 letters)
MS.Add.8954 'Men of letters' (162 letters)
MS.Add.8955 'Actors, artists, musicians' (95 letters)