Letter listing for 1840–1849
- Rousseau à Wootton by William Howitt, 1840
- Témoignages sur Mme d'Houdetot et Rousseau by Marie Louise Élisabeth Vigée Le Brun [née Vigée], 1840
- Caroline Lucretia Herschel [née Herschel] to Lady Margaret Brodie Herschel [née Stewart], 10 January 1840
- Caroline Lucretia Herschel [née Herschel] to Lady Margaret Brodie Herschel [née Stewart], 10 January 1840
- Sir Roderick Impey Murchison to Reverend William Venables Vernon Harcourt, 22 March 1840
- Caroline Lucretia Herschel [née Herschel] to Lady Margaret Brodie Herschel [née Stewart], 5 April 1840
- Caroline Lucretia Herschel [née Herschel] to Sir John Frederick William Herschel, 1st baronet of Slough, 6 July 1840
- Caroline Lucretia Herschel [née Herschel] to Lady Margaret Brodie Herschel [née Stewart], 3 August 1840
- Sir John Frederick William Herschel, 1st baronet of Slough to Caroline Lucretia Herschel [née Herschel], 10 August 1840
- Sir John Frederick William Herschel, 1st baronet of Slough to Caroline Lucretia Herschel [née Herschel], 10 August 1840
- Conference documents by [unknown], September 1840
- Caroline Lucretia Herschel [née Herschel] to Sir John Frederick William Herschel, 1st baronet of Slough, 1 September 1840
- Reverend William Venables Vernon Harcourt to Henry Peter Brougham, 1st Baron Brougham and Vaux, 13 September 1840
- Reverend William Whewell to Sir Roderick Impey Murchison, 18 September 1840
- Sir Edward Sabine to Sir Roderick Impey Murchison, 21 September 1840