From A Compendium of Irish Biography, 1878
Derrick, Samuel, a writer, the friend of Johnson and Boswell, occasionally referred to in Boswell's Johnson, was born in Dublin in 1724. Abandoning the linen-drapery business, he went to London in 1751, made an unsuccessful appearance upon the stage as an actor, and wrote some poetical pieces of a secondary character. Johnson, when asked whether Derrick or Smart was the better poet, replied : "Sir, it is not easy to settle the point of precedency between a louse and a flea." His flighty, careless way of living involved him in repeated monetary embarrassments; but when Beau Nash died, he had the good fortune to be chosen to succeed him as Master of the Ceremonies at Bath. The best known of his works (of which works a list will be found in Allibone) are his Letters, written from Liverpool to Chester, published in 1767. A collection of his jests appeared the year he died, 1769.
16. Authors, Dictionary of British and American: S. Austin Allibone. 3 vols. Philadelphia, 1859-'71.
39. Biographical Dictionary, Imperial: Edited by John F. Waller. 3 vols. London, N.D.
46. Boswell's Life of Samuel Johnson; with Notes and Illustrations: Edward Malone, London, 1848.