Essential oils, short for quintessential oils, are highly-concentrated, aromatic liquids that are distilled with either water or steam from the leaves, roots, stems, flowers, or bark of a plant. The quintessential oil derived its name from the fifth Aristotelian element, æther; Aristotle believed that it was made up of heavenly bodies. As this element became extremely popular with medieval alchemists, they renamed it quintessence. They…