"The Welsh Nonconformists' Memorial; or, Cambro-British Biography", edited by John Evans, was published posthumously in 1820. A miscellaneous collection, much of it,  including an account of Michael Servetus, had originally appeared in the "Monthly Repository" under the pseudonym "Gwilym Emlyn". To the "Gentleman's Magazine" for October 1789, he contributed a letter  (dated 14 October 1789, and signed Gwilym Dyfed), supporting the story of the discovery of America by Madoc. He wrote for the three volumes of the "Cambrian Register", 1796–1818.