Aromatherapy: the use of essential oils and other fragrances from plants to affect someone's mood or health, and is commonly associated with alternative medicine.

• An essential oil is a water-immiscible material produced by distillation from some plant material. The material (flowers, leaves, stems, or roots, depending on the plant) is put in an alembic over water, and the volatile compounds, which require less vapor pressure to evaporate with the presence of steam, distill into a receiving vessel. The upper portion is the oil, the lower being the hydrosol. They are drained with two spigots. Most oils are distilled in a single process. The exception is ylang-ylang, which takes 22 hours to complete distillation. It is distilled fractionally, producing several grades.
  
  

Many essential oils have medicinal properties that have been applied in folk medicine since ancient times and are still widely used today. One of the best known essential oils for aromatherapy is lavender, which is recommended by practitioners for treating wounds, and to aid sleep by combating anxiety and insomnia. Other popular scents include rose and jasmine. © 2004