Quintessence is the fifth element proposed by medieval alchemists as the stuff that makes up the heavenly bodies. Although quintessence was extremely rare on the terrestrial sphere, it was considered panacea and medicinal alchemists worked to isolate it, which, it was claimed, could be accomplished through sufficient distillation of alcohol.
Quintessence is sometimes described as Aether, Spirit or Akasha and the term is used in modern physics to describe a theoretical type of dark energy.
Suggested Reading
The Hermetic Arcanum
The Book of Quintessence
