40 Fun Facts About Aromatherapy

Which sour citrus fruit, grown on a large scale in Calabria in Italy, gives Earl Grey tea its flavour?

Bergamot is so tied to Reggio di Calabria that the fruit has become a symbol of the entire city. Its aromatic oil also flavours Turkish delight.

Which aromatic resin from Boswellia trees of Somalia and Oman was one of the three gifts of the Magi?

Frankincense is harvested so heavily that researchers warn every Boswellia species is threatened by overexploitation and habitat loss.

Which conifer's berry-like cones are distilled for aromatherapy oil and also give gin its distinctive flavour?

Juniper cones flavour gin while they are fully grown but still unripe, whereas cooks usually prefer the mature, dark berries.

Which tree, whose leaves make up most of a koala's diet, yields an essential oil rich in cineole?

Eucalyptus leaves are low in nutrition and contain toxic compounds that deter most other mammals from feeding on them.

Wintergreen oil is about 98% methyl salicylate, a close chemical relative of which common painkiller?

Aspirin is such a close cousin that one millilitre of wintergreen oil equals almost six regular-strength adult tablets, which makes swallowing the oil dangerous.

Thieves oil blends recall a legend in which a herbal vinegar shielded four robbers from which disease?

Plague protection made four thieves vinegar famous: in the usual story, robbers caught looting the dead and the sick traded their secret recipe for leniency.

German chamomile oil takes which unexpected colour from a compound formed during distillation?

Blue is absent from the living flower: the pigment chamazulene forms only when a compound called matricin breaks down in the still, which is why the plant is nicknamed blue chamomile.

Which oil from a bushy herb of the mint family surged in popularity with the hippie movement of the 1960s?

Patchouli even scented a toy: in 1985 Mattel mixed the oil into the plastic of Stinkor, a Masters of the Universe action figure.

Many citrus essential oils are best kept off exposed skin because they increase its vulnerability to what?

Sunlight activates compounds called furanocoumarins in the oils, and the exposed skin can redden, burn and blister within a day or two.

Which French novelist's name is attached to the way a smell can suddenly revive vivid memories?

Marcel Proust wrote in his novel Swann's Way of the taste and smell of a madeleine dipped in linden tea bringing back vivid recollections of the past.

Which herb, a classic filling for linen sachets, yields an oil rich in linalool?

Lavender oil is steam-distilled from blooms harvested between late June and August, and like every essential oil it is a complex mixture, not one pure compound.

Which compound in peppermint oil triggers the skin's cold-sensitive receptors, producing a cooling sensation?

Menthol works by chemically triggering TRPM8, the receptors that normally sense cold, so the chill is felt whether it is inhaled, eaten or rubbed on.

Which spice yields an essential oil, rich in eugenol, that is a traditional remedy for toothache?

Clove oil dabbed into a cavity in a decayed tooth may relieve the ache for a while, and the same oil flavours tea and toothpaste.

Which oil from Melaleuca alternifolia leaves has been produced commercially in Australia since the 1920s?

Tea tree oil is strictly for external use: it is poisonous if swallowed, and in Australia it is among the oils behind poisonings, mostly of children.

Which grass-derived oil has been registered in the United States as a plant-based insect repellent since 1948?

Citronella is best known from outdoor candles, yet the candles themselves are not effective at repelling the mosquitoes that spread dengue fever.

Which German city gave its name to the light citrus perfume launched there by Giovanni Maria Farina in 1709?

Cologne owes its famous export to an Italian: Farina came from Santa Maria Maggiore, and his secret formula has been made in the German city ever since.

Unlike an essential amino acid, an essential oil is named for carrying what characteristic of its source plant?

Its fragrance is the 'essence' the name refers to, the characteristic smell released when the plant is crushed or put through a steam process.

Essential oils are also called volatile oils because their aroma compounds readily do what at room temperature?

Evaporate quickly is what volatile means in chemistry: rubbing alcohol vanishes in moments, while a low-volatility liquid such as cooking oil stays put.

In a perfume or essential oil blend, which name is given to the light scents sensed first, which fade fastest?

Top notes are made of small, light molecules, so they are sensed the moment a blend is applied, while some base notes linger for more than a day.

What name is given to a vegetable oil, such as sweet almond, used to dilute essential oils for massage?

Carrier oil is also known as base oil, and the true ones are generally cold-pressed or macerated vegetable oils, picked partly for how thick they feel.

Which so-called oil, from the seeds of a shrub native to Arizona and Mexico, is chemically a liquid wax?

Jojoba is about 97% wax esters, with only a tiny fraction of the triglycerides found in true vegetable oils, though it pours just like one.

Which French chemist coined the word aromatherapy and made it the title of his 1937 book?

René-Maurice Gattefossé titled his book Aromathérapie, and its subtitle went further, describing essential oils as plant hormones.

Which Persian author of The Canon of Medicine is often credited with distilling rose essence using steam?

Avicenna, known in Persian as Ibn Sina, is said to have used the rose oil he distilled in treatments for heart conditions.

Which ancient people made kyphi, a compound incense with recipes inscribed on temple walls at Edfu and Philae?

Egyptians used kyphi for both religious and medical purposes, and the priest Manetho is said to have written a whole treatise on preparing it.

Which French Riviera town is the centre of France's perfume industry and styled the world's perfume capital?

Grasse was a leather-tanning town first: its makers began scenting gloves to mask the smell of the hides, and perfume outlived the leather trade.

Which country's Rose Valley, centred on the town of Kazanlak, has supplied rose oil to perfumers for centuries?

Bulgaria won European protected status for its rose oil in 2014, and the valley holds festivals celebrating the roses and their oil every year.

Which tropical tree, known by a Tagalog name, bears yellow flowers that yield a widely used perfume oil?

Ylang-ylang is the Spanish spelling of the tree's Tagalog name, ilang-ilang, and in the Philippines its flowers are strung into necklaces.

Neroli oil, named after a princess of Nerola who scented her gloves with it, comes from which tree's blossom?

Bitter orange blossom became fashionable in the late 17th century, when Anne Marie Orsini, princess of Nerola, used it to perfume her gloves and her bath.

Which scented wood, long produced in southern India, needs trees at least 15 years old to yield valuable oil?

Sandalwood powder is sprinkled over the giant Gommateshwara statue during a festival held only once every 12 years.

Which Mediterranean herb do mourners toss into graves as a symbol of remembrance for the dead?

Rosemary has an aroma of pine, and several Shakespeare plays refer to its use in burial and memorial rites.

Which technique captures the scent of delicate flowers by laying petals on glass plates smeared with fat?

Enfleurage was developed in southern France and was long the sole way to capture jasmine and tuberose, whose aromas the heat of distillation would destroy.

In perfumery, what is the concentrated extract obtained by washing a waxy concrete with ethanol called?

Absolute production suits raw materials too delicate or too inert to be steam-distilled, which give up their aroma only to a solvent such as hexane.

What do aromatherapists call the scented liquid left over from steam distillation once the essential oil is removed?

Hydrosol was once treated as a mere byproduct of distillation, but it is now valued as a co-product and used in skincare as floral water.

Which gas, used as a supercritical fluid, extracts essential oils from plants and caffeine from coffee?

Carbon dioxide is the most widely used supercritical fluid, reaching that state above just 31 °C and 74 bar, and brewers use the same method to extract hops.

Cold pressing, used instead of distillation for citrus oils, extracts the oil from which part of the fruit?

The peel holds the oil, and international standards count this mechanical pressing alongside steam distillation as a way to make a true essential oil.

Nerve fibres from the nose connect directly to which brain network involved in emotion and long-term memory?

Limbic system structures include the amygdala, which forms memories of emotional experiences and sends direct projections to the hippocampus.

What is the scientific term for the sense of smell, by which inhaled essential oil molecules are detected?

Olfaction can even pick out family: research suggests that humans are able to detect their blood relatives by smell.

Which condition, also known as smell blindness, was widely reported as a neurological symptom of COVID-19?

Anosmia can be dangerous as well as dulling, because it hinders the detection of gas leaks, fire and spoiled food.

Which mixture of dried, scented plant material has a French name borrowed from a Spanish stew, olla podrida?

Potpourri literally means rotten pot, and much of what is sold today is plain dried plant material with strong perfume and dye added.

German chemist Otto Wallach won a Nobel Prize after systematically analysing which compounds found in essential oils?

Terpenes are mostly liquid, so Wallach had to convert them step by step into crystalline compounds before he could work out their structures.