Allison Henry offers a short introduction to essential oils: where they come from and what they are. In this video: • How the Egyptians, Greeks, and Romans used oils for medicine, ceremony, and perfume. • Their place in traditional medicine, and their rise in the West in the 20th century. • What an essential oil is: aromatic compounds drawn from flowers, leaves, bark, and roots by steam distillation or cold pressing. • Why each oil is so complex and potent. Good for anyone just getting started with essential oils.