Aristotle's (384-322 BC)

Four Elements

Four elements and four qualities: Earth (cold & dry), Water (cold & wet), Air (hot & wet), and Fire (hot & dry). All matter is composed of these four elements in varying proportions. For example, a burning log exhibits flames (fire), smoke (air), hissing steam (water), and ashes (earth).

Paracelsus' (1493-1541) 

Three principles

• exalted sulfur of the philosophers (soul); think color & combustibility
• exalted mercury of the philosophers (spirit); think luster & hardness
• salt (material body); think solidness & fire resistance
• all matter is composed of these three principles in varying proportions
• a burning log exhibits combustible sulfur, volatile mercury, and ashes (salt)

Boyle