William Butler, Irish alchemist (c. 1534 – 29 January 1617), was, according to the Compendium of Irish Biography, "a well-known alchemist, one of the discoverers of the philosopher's stone, and of a powder for bringing the dead to life, was born in Clare about 1534.[1] He died at sea, on his passage to Spain, 29th January 1617."
The sources cited for his life by the Compendium were the Nouvelle Biographie Générale (46 volumes, Paris, 1855-1866), of which it stated "An interleaved copy, copiously noted by the late Dr. Thomas Fisher, Assistant Librarian of Trinity College, Dublin."