The collection consists of selected correspondence, poems, and epitaphs of Hayley. Included are a letter (1789) from Charles Davy; one letter from Joseph Hill (1807) about William Cowper; one letter (1812) to Cadell and Davies, the London publishers, regarding books he did not receive and their response written on the same letter; one letter (1810) to a friend ("Clara"), with a long crisscrossed letter to Clara from Mrs. Hayley on the verso; one letter from A. Flaxman (1819) mentioning John Flaxman; one letter of thanks (1808) to William Hersee; one letter (1800) from Sir Francis Milman regarding Hayley's son's health; one letter (1811) to Tom Payne, bookseller in London, asking him to take over a failed transaction with another publisher; one letter (1806) to "Mrs. Rawlinson" thanking her for sending him a portrait of Darwin painted by his friend George Romney; two letters (1811, 1819) from John Singer Sargent; one letter (1806), with an epitaph, to Charlotte Mary Smith about the death of her mother; one letter (1797) to Lord Spencer asking him to consider offering a job to his friend Samuel Rose and informing him of the death of Mrs. Cowper; one letter (1775) by John B. Thornton; a letter of thanks (1801) to "Mr. Waldron"; one letter (1792) by Joseph Cooper Walker; one letter (1791) to "Sir" which includes a short poem beginnning with "Tho not a stranger ... "; and one letter (1799) to an unidentified recipient about Hayley's son's illness. Hayley signed several of his letters "Hermit."

In addition, there are several poetical manuscripts: an epitaph (1802?) on George Romney, a poem (1811) "To Clara," and a sonnet ("Let Exultation bless the hallow'd Hour . . . ") which is included in a letter (1808) to an unidentified friend about the health of the friend's father.