He wrote the "Sonnet on Parting with his Books" on the 1816 sale of his library. In 1822 he issued an appendix of illustrations to his Lorenzo and also a "Memoir of Richard Robert Jones of Aberdaron", a remarkable self-taught linguist. The year 1824 was memorable for the death of his wife and the publication of his edition of the works of Alexander Pope, which involved him in a controversy with William Lisle Bowles. His versatility was shown by the appearance of a folio monograph on the "Monandrian Plants", which was published in 1828. The last part came out after his recovery from a stroke.