Essential oil .

An essential oil is a concentrated, hydrophobic liquid containing volatile aromatic compounds extracted from plants. It may be produced by distillation, expression, or solvent extraction. Essential oils are used in perfumery , aromatherapy, cosmetics, incense, medicine, household cleaning poducts, and for flavoring food and drink. They are valuable commodities in the fragrance and food industries.

Essential oil is also known as volatile oil and ethereal oil . It may also be referred to as "oil of" the raw plant material from which it was extracted, such as oil of clove . The term essential is intended to convey that the oil is an essence of the plant it is extracted from, and not in the more common sense of being indispensible; do not confuse them with essential fatty acids.

Seen above, a traditional alembic, consisting of two tanks connected by a tube for the distillation of lavender in Provence.

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