About Lesson
During the Middle Ages, early chemists were desperately searching for what they called the “quintessence” of life—an elusive fifth element in addition to earth, fire, water, and air. Building on the discoveries of Avicenna, these alchemists experimented with plant distillation. While experimenting, they discovered a substance rising to the surface of the water during the distillation process. At this point in history, any substance that didn’t mix with water was classified as an oil. With this discovery, the alchemists believed they’d found the quintessence they had been looking for—the essence of all life. This is how the term essential oil was born.