The name Parazelsus is derived from Swiss doctor & alchemist Philippus Theophrastus Aureolus Bombastus von Hohenheim (1493-1541), who took the name Paracelsus later in life. He referred to Celsus, the Roman Encyclopedist for Medicine, but meant to move medicine beyond his times. Paracelsus introduced the treatment of illnesses with chemical substances during the Renaissance period. Many early advances in modern medicine are based on the research and work performed by Paracelsus.