 He compiled "A Collection of Affidavits and Certificates Relative to the Wonderful Cure of Mrs. Ann Mattingly, Which Took Place in the City of Washington, D.C., on the Tenth of March, 1824".By way of Anthony Kohlmann, this pamphlet made its way to Pope Leo XII, who had it translated into Italian and published by his personal printer.By 1806, Matthews had become vice president of Georgetown College, and by 1808, he had become a member of its board of directors, where he served until 1815.