The Reverend Leonard Chappelow (1744-1820), fellow of the Royal Society and chaplain to the Earl of Bradford, was a close friend of HLP and a prolific correspondent. The volumes contain letters from HLP to Leonard Chappelow, with some letters from Chappelow to HLP, as follows:
- Volume 1 (Eng MS 559), numbers 1-57, 1786-1797;
- Volume 2 (Eng MS 560), numbers 58-113, 1797-1801;
- Volume 3 (Eng MS 561), numbers 114-166, 1801-1818.
Number 1 is a letter from George Jenyns, Chappelow's executor, to HLP saying that he has found her letters to Chappelow and intends to return them (19 September 1820). Numbers 155-166 are letters from Chappelow either undated or omitting the year.