The Encyclopedia of Essential Oils (9 page)

GENERAL DESCRIPTION A large tropical tree up to 20 metres high with pale green citrus-like leaves, whitish underneath, bearing hard-shelled flattish fruit about the size of a nutmeg. The benzoin is a pathological product, formed when the trunk is cut; the tree exudes a balsamic resin which hardens upon exposure, to air and sunlight.

DISTRIBUTION Native to tropical Asia; the two main regions of production are Sumatra, Java and Malaysia for ‘Sumatra’ benzoin, and Laos, Vietnam, Cambodia, China and Thailand for ‘Siam’ benzoin.

OTHER SPECIES There are many different varieties within the Styrax family which produce benzoin, but these are generally classified under either Sumatra benzoin
(S. paralleloneurus)
or Siam benzoin
(S. tonkinensis)
– see also Botanical Classification section.

HERBAL/FOLK TRADITION It has been used for thousands of years in the east as a medicine and incense; the fumigations were believed to drive away evil spirits. It was used by the Chinese herbalists for its heating and drying qualities, as a good urinary antiseptic and as an aid to digestion.

In the west, it is best known in the form of compound tincture of benzoin or Friars Balsam, used for respiratory complaints. Externally it is used for cuts and irritable skin conditions; internally it is used as a carminative for indigestion, etc. It also acts as a preservative of fats.

ACTIONS Anti-inflammatory, anti-oxidant, antiseptic, astringent, carminative, cordial, deodorant, diuretic, expectorant, sedative, styptic, vulnerary.

EXTRACTION The crude benzoin is collected from the trees directly. Benzoin resinoid, or ‘resin absolute’, is prepared from the crude using solvents, for example benzene and alcohol, which are then removed. Commercial benzoin is usually sold dissolved in ethyl glycol or a similar solvent. A ‘true’ absolute is also produced in small quantities.

CHARACTERISTICS 1. Sumatra crude benzoin occurs as greyish-brown brittle lumps with reddish streaks, with a styrax-like odour. There are several different qualities available; the so-called ‘almond’ grade is considered superior. 2. Siam benzoin comes in pebble or tear-shaped orange-brown pieces, with a sweet-balsamic vanilla-like scent, this type having a more refined odour than the Sumatra type.

Benzoin resinoid is produced from both the Siam and Sumatra types, or a mix of the two. It is an orange-brown viscous mass with an intensely rich sweet-balsamic odour. It blends well with sandalwood, rose, jasmine, copaiba balsam, frankincense, myrrh, cypress, juniper, lemon, coriander and other spice oils.

PRINCIPAL CONSTITUENTS 1. Sumatra Benzoin: mainly coniferyl cinnamate and sumaresinolic acid, with benzoic acid, cinnamic acid, and traces of styrene, vanillin and benzaldehyde. 2. Siam benzoin: mainly coniferyl benzoate (65–75 per cent), with benzoic acid, vanillin, siaresinolic acid and cinnamyl benzoate.

SAFETY DATA Non-toxic, non-irritant, possible sensitization. Compound benzoin tincture is ‘regarded as moderately toxic, due probably to occasional contact dermatitis developed in some individuals … which contains, in addition to benzoin, aloe, storax, Tolu balsam and others.’
⁹

AROMATHERAPY/HOME USE

SKIN CARE
: Cuts, chapped skin, inflamed and irritated conditions.

CIRCULATION, MUSCLES AND JOINTS
: Arthritis, gout, poor circulation, rheumatism.

RESPIRATORY SYSTEM
: Asthma, bronchitis, chills, colic, coughs, laryngitis.

IMMUNE SYSTEM
: ’Flu.

NERVOUS SYSTEM
: Nervous tension and stress-related complaints. It warms and tones the heart and circulation, both physically and metaphorically: ‘This essence creates a kind of euphoria; it interposes a padded zone between us and events.’
¹⁰

OTHER USES Compound benzoin tincture is used in pharmaceuticals and in dentistry to treat gum inflammation. The resinoid and absolute are used extensively as fixatives and fragrance components in soaps, cosmetics, toiletries and perfumes, especially Siam benzoin. Both types are used in most food categories, including alcoholic and soft drinks.

Citrus bergamia

FAMILY Rutaceae

SYNONYM
Citrus aurantium subsp. bergamia.

GENERAL DESCRIPTION A small tree, about 4.5 metres high with smooth oval leaves, bearing small round fruit which ripen from green to yellow, much like a miniature orange in appearance.

DISTRIBUTION Native to tropical Asia. Extensively cultivated in Calabria in southern Italy and also grown commercially on the Ivory Coast.

OTHER SPECIES Not to be confused with the herb bergamot or bee balm
(Monarda didyma).

HERBAL/FOLK TRADITION Named after the Italian city of Bergamo in Lombardy, where the oil was first sold. The oil has been used in Italian folk medicine for many years, primarily for fever (including malaria) and worms; it does not feature in the folk tradition of any other countries. However, due to recent research in Italy, bergamot oil is now known to have a wide spectrum of applications, being particularly useful for mouth, skin, respiratory and urinary tract infections.

ACTIONS Analgesic, anthelmintic, antidepressant, antiseptic (pulmonary, genito-urinary), antispasmodic, antitoxic, carminative, digestive, diuretic, deodorant, febrifuge, laxative, parasiticide, rubefacient, stimulant, stomachic, tonic, vermifuge, vulnerary.

EXTRACTION Essential oil by cold expression of the peel of the nearly ripe fruit. (A rectified or terpeneless oil is produced by vacuum distillation or solvent extraction.)

CHARACTERISTICS A light greenish-yellow liquid with a fresh sweet-fruity, slightly spicy-balsamic undertone. On ageing it turns a brownish-olive colour. It blends well with lavender, neroli, jasmine, cypress, geranium, lemon, chamomile, juniper, coriander and violet.

PRINCIPAL CONSTTTUENTS Known to have about 300 compounds present in the expressed oil: mainly linalyl acetate (30–60 per cent), linalol (11–22 per cent) and other alcohols,
sesquiterpenes, terpenes, alkanes and furocoumarins (including bergapten, 0.30–0.39 per cent).

SAFETY DATA Certain furocoumarins, notably bergapten, have been found to be phototoxic on human skin; that is, they cause sensitization and skin pigmentation when exposed to direct sunlight (in concentration and in dilution even after some time!). Extreme care must be taken when using the oil in dermal applications – otherwise a rectified or ‘bergapten-free’ oil should be substituted. Available information indicates it to be otherwise non-toxic and relatively non-irritant.

AROMATHERAPY/HOME USE

SKIN CARE
: Acne, boils, cold sores, eczema, insect repellent and insect bites, oily complexion, psoriasis, scabies, spots, varicose ulcers, wounds.

RESPIRATORY SYSTEM
: Halitosis, mouth infections, sore throat, tonsillitis.

DIGESTIVE SYSTEM
: Flatulence, loss of appetite.

GENITO
-
URINARY SYSTEM
: Cystitis, leucorrhoea, pruritis, thrush.

IMMUNE SYSTEM:
Colds, fever, ’flu, infectious diseases.

NERVOUS SYSTEM
: Anxiety, depression and stress-related conditions, having a refreshing and uplifting quality.

OTHER USES Extensively used as a fragrance and, to a degree, a fixative in cosmetics, toiletries, suntan lotions and perfumes – it is a classic ingredient of eau-de-cologne. Widely used in most major food categories and beverages, notably Earl Grey tea.

Betula lenta

FAMILY Betulaceae

SYNONYMS
B. capinefolia
, cherry birch, southern birch, mahogany birch, mountain mahogany.

GENERAL DESCRIPTION A graceful tree about 25 metres high which has a pyramidal shape while young. It has bright green leaves and a dark reddish-brown aromatic bark, which is broken into plates or patches.

DISTRIBUTION Native to southern Canada and southeastern USA; produced mainly in Pennsylvania.

OTHER SPECIES There are numerous species of birch, spanning several continents, such as black birch
(B. nigra)
found in North America. Not to be confused with the European white birch
(B. alba)
, which produces birch tar oil used in chronic skin diseases.

HERBAL/FOLK TRADITION The cambium (the layer directly under the bark) is eaten in the spring, cut into strips like vermicelli. The bark, in the form of an infusion, is used as a general stimulant and to promote sweating. As a decoction or syrup, it is used as a tonic for dysentery and is said to be useful in genito-urinary irritation. The flavour of wintergreen and birch bark, in the form of a tea, was popular with the American Indians and European settlers. More recently, this has been translated into a preference for ‘root beer’ flavourings.

ACTIONS Analgesic, anti-inflammatory, antipyretic, antirheumatic, antiseptic, astringent, depurative, diuretic, rubefacient, tonic.

EXTRACTION Essential oil by steam distillation of the bark macerated in warm water.

CHARACTERISTICS Colourless, pale yellow or reddish tinted liquid with an intense, sweet-woody, wintergreen-like scent.

PRINCIPAL CONSTITUENTS Almost entirely methyl salicylate (98 per cent), produced during the maceration process. It is almost identical in composition to wintergreen oil.

SAFETY DATA Methyl salicylate, the major constituent, is not exactly toxic but very
harmful in concentration.’ It can be absorbed through the skin, and fatal poisoning via this route has been reported.’
¹¹
’ It is also classed as an enviromental hazard or marine pollutant.

AROMATHERAPY/HOME USE None.

OTHER USES Limited use as a counter-irritant in anti-arthritic and antineuralgic ointments and analgesic balms. Limited use as a fragrance component in cosmetics and perfumes; extensively used as a flavouring agent, especially ‘root beer’, chewing gum, toothpaste, etc. (usually very low-level use).

Betula alba

FAMILY Betulaceae

SYNONYMS
B. alba var. pubescens, B. odorata, B. pendula
, European white birch, silver birch.

GENERAL DESCRIPTION Decorative tree, up to 15–20 metres high, with slender branches, silvery-white bark broken into scales, and light green oval leaves. The male catkins are 2–5 cms long, the female up to 15 cms long.

DISTRIBUTION Native to the northern hemisphere; found throughout Eastern Europe, Russia, Germany, Sweden, Finland, the Baltic coast, northern China and Japan.

OTHER SPECIES Many cultivars exist of this species of birch. The paper birch
(B. papyrifera)
and
B. verrucosa
are also used for the production of birch bud oil and/or birch tar. NB Should not be confused with the oil from the sweet birch
(B. lenta)
which is potentially toxic.

HERBAL/FOLK TRADITION Birch buds were formerly used as a tonic in hair preparations. Birch tar is used in Europe for all types of chronic skin complaints: psoriasis, eczema, etc. In Scandinavia the young birch leaflets and twigs are bound into bundles and used in the sauna to tone the skin and promote the circulation. The sap is also tapped in the spring and drunk as a tonic. Buds, leaves and bark are used for ‘rheumatic and arthritic conditions, especially where kidney functions appear to need support … oedematous states; urinary infections and calculi.’
¹²

ACTIONS Anti-inflammatory, antiseptic, cholagogue, diaphoretic, diuretic, febrifuge, tonic.

EXTRACTION 1. Essential oil by steam distillation from the leaf-buds. 2. Crude birch tar is extracted by slow destructive distillation from the bark; this is subsequently steam-distilled to yield a rectified birch tar oil.

CHARACTERISTICS 1. Pale yellow, viscous oil with a woody-green balsamic scent. It crystallizes at low temperatures. 2. The crude tar is an almost black, thick oily mass. The rectified oil is a brownish-yellow, clear oily liquid with a smoky, tar-like, ‘Russian leather’ odour. It blends well with other woody and balsamic oils.

PRINCIPAL CONSTITUENTS 1. Mainly betulenol and other sesquiterpenes. 2. In the tar oil: phenol, cresol, xylenol, guaiacol, creosol,
pyrocatechol, pyrobetulin (which gives the ‘leather’ scent).

SAFETY DATA Non-toxic, non-irritant, non-sensitizing.

AROMATHERAPY/HOME USE
SKIN CARE
: Dermatitis, dull or congested skin, eczema, hair care, psoriasis etc.
CIRCULATION, MUSCLES AND JOINTS
: Accumulation of toxins, arthritis, cellulitis, muscular pain, obesity, oedema, poor circulation, rheumatism.

OTHER USES Birch bud oil is used primarily in hair tonics and shampoos, and in some cosmetics for its potential skin-healing effects. The crude tar is used in pharmaceutical preparations, ointments, lotions, etc. for dermatological diseases. It is also used in soap and leather manufacture – rectified birch tar oil provides the heart for many ‘leather’ type perfumes and aftershaves.

Peumus boldus

FAMILY Monimiaceae

SYNONYMS
Boldu boldus, Boldoa fragrans
, boldus, boldu.

GENERAL DESCRIPTION An evergreen shrub or small tree up to 6 metres high, with slender branches, sessile coarse leaves and bearing yellowish-green fruit; when dried the leaves turn a deep reddish-brown colour. The whole plant is aromatic.