Sometimes called the founder of modern chemistry, the Seventeenth-century natural philosopher Robert Boyle is credited with transforming chemistry from an occult discipline to a modern science in which theory and practical experiment support and advance each other. Influenced by Bacon and Descartes, Boyle formulated his empirically based “corpuscular” theory of the constitution of matter, which freed chemistry from the then accepted notion of elements – “whether the earth, air, fire, and water of the Aristotelians; the salt, sulfur, and mercury of the Paracelsans; [or] the phlegm, oil, spirit, acid and alkali of later chemists.”