Читать книгу Encyclopedia of Essential Oils: The complete guide to the use of aromatic oils in aromatherapy, herbalism, health and well-being. - Julia Lawless - Страница 9

When we peel an orange, walk through a rose garden or rub a sprig of lavender between our fingers, we are all aware of the special scent of that plant. But what exactly is it that we can smell? Generally speaking, it is essential oils which give spices and herbs their specific scent and flavour, flowers and fruit their perfume. The essential oil in the orange peel is not difficult to identify; it is found in such profusion that it actually squirts out when we peel it. The minute droplets of oil which are contained in tiny pockets or glandular cells in the outer peel are very volatile, that is, they easily evaporate, infusing the air with their characteristic aroma.

A Herbalist’s Garden; Le Jardin de Santé, 1539

But not all plants contain essential or volatile oils in such profusion. The aromatic content in the flowers of the rose is so very small that it takes one ton of petals to produce 300g of rose oil. It is not fully understood why some plants contain essential oils and others not. It is clear that the aromatic quality of the oils plays a role in the attraction or repulsion of certain insects or animals. It has also been suggested that they play an important part in the transpiration and life processes of the plant itself, and as a protection against disease. They have been described as the ‘hormone’ or ‘life-blood’ of a plant, due to their highly concentrated and essential nature.

Aromatic oils can be found in all the various parts of a plant, including the seeds, bark, root, leaves, flowers, wood, balsam and resin. The bitter orange tree, for example, yields orange oil from the fruit peel, petitgrain from the leaves and twigs, and neroli oil from the orange blossoms. The clove tree produces different types of essential oil from its buds, stalks and leaves, whereas the Scotch pine yields distinct oils from its needles, wood and resin. The wide range of aromatic materials obtained from natural sources and the art of their extraction and use has developed slowly over the course of time, but its origins reach back to the very heart of the earliest civilizations.