Letter listing for 1800–1809
- Aaron Burr to Jeremy Bentham, 19 April 1809
- Hester Lynch Piozzi [formerly Mrs Thrale; née Salusbury] to Sir John Salusbury Piozzi Salusbury [née Piozzi], 19 April 1809
- Adam Ferguson to John Lee, 25 April 1809
- Hester Lynch Piozzi [formerly Mrs Thrale; née Salusbury] to Lady Margaret Williams, 26 April 1809
- Hester Lynch Piozzi [formerly Mrs Thrale; née Salusbury] to Sir John Salusbury Piozzi Salusbury [née Piozzi], 26 April 1809
- James Mill to Jeremy Bentham, 27 April 1809
- Jacques Henri Bernardin de Saint-Pierre to Marguerite Charlotte Désirée de Saint-Pierre [née de Pelleporc], 27 April 1809
- Jacques Henri Bernardin de Saint-Pierre to Marguerite Charlotte Désirée de Saint-Pierre [née de Pelleporc], 30 April 1809
- Hester Lynch Piozzi [formerly Mrs Thrale; née Salusbury] to Lady Margaret Williams, 1 May 1809
- Hester Lynch Piozzi [formerly Mrs Thrale; née Salusbury] to Sir John Salusbury Piozzi Salusbury [née Piozzi], 1 May 1809
- Francis Horner to Jeremy Bentham, 2 May 1809
- Hester Lynch Piozzi [formerly Mrs Thrale; née Salusbury] to Reverend Leonard Chappelow, 2 May 1809
- Jacques Henri Bernardin de Saint-Pierre to Marguerite Charlotte Désirée de Saint-Pierre [née de Pelleporc], 3 May 1809
- Hester Lynch Piozzi [formerly Mrs Thrale; née Salusbury] to Sir John Salusbury Piozzi Salusbury [née Piozzi], 6 May 1809
- Hester Lynch Piozzi [formerly Mrs Thrale; née Salusbury] to Samuel Lysons, 8 May 1809