Generally speaking, everyone appreciates the smell of plants. Just think of a rose and you will understand immediately. In the middle ages, people determined the use of the plants on the basis of their smell. For example, when they found a plant that kept away insects, they assumed that it would serve well to keep insects out of the house. At the time, these people believed insects to carry often serious diseases. Similarly, some people used certain herbs to purify the air believing it could transmit certain diseases. The roads that royalty and their followers used in the past centuries were usually strewed with dried herbs, such as rosemary, thyme or rue. The purpose was to protect the rulers and their families from diseases like the pest.

The essential oils contained in aromatic herbs are responsible for the various scents the plants exude. They are often used in the cosmetic industry, the perfume industry and in aromatherapy. The latter aims to achieve a therapeutic effect by means of massage, inhalations or baths with the essential oils of plants. Essential oils are located in the tiny glands in the various parts of aromatic plants: in the leaves, which is the case with basil; in the flower, in the case of the rose; in the fruit, in the case of lemon, in the seeds in the case of coriander, in the bark in the case of cinnamon and in the roots in the case of certain other plants.

Essential oils were first used in the Middle East as well as the far east. They play an important role in Ayurvedic healing which originates in India. The distillation techniques have their roots in Arabia. Here they were also refined. Extraction by steam appeared to be the best method to maintain both the perfumes of the aromatic plants and their therapeutic capacities. Apparently, the people that participated in the crusades are the ones who brought these techniques to the East some centuries ago.

The term aromatherapy has been coined by the French professor René-Maurice Gattefosse, a chemist who used the essential oil of lavender to cure injuries and infections during the Great War. He believed that lavender was the the best disinfectant known at the time. Apparently, essential oils are transported by the blood system to all the organs in the human body before it exits the body. This process can take 30 minutes to 12 hours. As an experiment, you can try to rub a bit of garlic under your foot and smell your breath some hours afterwards. (I have to admit that I haven't tried this yet, but it seems to be a conclusive proof, should it work.)

Usually, essential oils are applied by means of massage, but they can also be inhaled or used in a bath. Generally speaking, they should not be eaten as they may be toxic. The extraction system is very complex and expensive, which explains the price of essential oils. Most of the oils are produced by means of distillation or enfleurage (A process in making perfume in which odourless fats or oils absorb the fragrance of fresh flowers). A huge quantity of plants is required to extract a minimum quantity of oil. For example, approximately 115 kg rose petals are required to produce 25 ml essential oil of roses.

When buying essential oils, always verify that they are authentic and not altered (which is the case if the price is very low). If they are altered the active ingredients of the oil may no longer be present. Use essential oil in small quantities. A couple of drops are sufficient for a massage, and therefore often mixed with a base oil, for example soft almond oil. Some drops of oil can be mixed with approximately 2½ cups of boiling water for inhalation.