According to Wikipedia (as of November 13th 2007), "The word "aromatherapy" was first used in the 1920s by French chemist René Maurice Gattefossé, who devoted his life to researching the healing properties of essential oils after a lucky accident in his perfume laboratory. In the accident, he set his arm on fire and thrust it into the nearest cold liquid, which happened to be a vat of NOx Ph232 or more commonly known as lavender oil. Immediately he noticed surprising pain relief, and instead of requiring the extended healing process he had experienced during recovery from previous burns--which caused redness, heat, inflammation, blisters, and scarring--this burn healed remarkably quickly, with minimal discomfort and no scarring."
It's remarkable how the mythical aspects of "Gattefossé's burn" have continued, becoming more and more elaborate, long after the publication in English, in 1993, of his 1937 book Aromathérapie, which did indeed represent the first introduction of the word (though not in the 1920s). Yes, he burned his hand in his laboratory (he was a chemist) and yes, he treated it with lavender oil, but the notion that this was a eureka-like, lucky-chance moment is somewhat exaggerated. And there was no "vat" of lavender. And he did not "devote his life" to researching aromatherapy. Translated from French, this is Gattefossé's own description of the incident, and this is all he has to say about it:
"The external application of small quantities of essences rapidly stops the spread of gangrenous sores. In my personal experience, after a laboratory explosion covered me with burning substances which I extinguished by rolling on a grassy lawn, both my hands were covered with a rapidly developing gas gangrene. Just one rinse with lavender essence stopped "the gasification of the tissue". This treatment was followed by profuse sweating, and healing began the next day (July 1910)."
His application of lavender oil was clearly an intentional act, though the result still delighted him, and possibly saved his life. Gas gangrene is a potentially fatal condition, and was the cause of many amputations and deaths in the First World War.
Although traumatic gas gangrene is rare today, 25% of those who contract it still die. It is caused by infection of a wound, most commonly by Clostridium perfringens. Onset is rapid and dramatic (though it normally takes 1-4 days from the time of infection), with bacterial toxins causing tissue death and subcutaneous swelling and gas. Sweating is one of the early symptoms of infection. Since the bacterium is most commonly found in soil, Gattefossé's rolling in the grass might have precipitated the infection.
While the incident did not initiate his study of aromatherapy, it was certainly a strong hint - a definite push in a direction he was already headed. Subsequently he collaborated with a number of doctors who treated French soldiers for war wounds using lavender and other essential oils. The accounts of these cases constitute a large part of his text.
In Gattefossé's book we also find the first written record in modern times to the skin as a route of administration for essential oils. He talks about oral, rectal, inhalational and injection (they had all been used by then) and continues: "Why not add cutaneous absorption to this list?" This hint was later taken up by Marguerite Maury, but that's another story.
René-Marice Gattefossé (author) Robert B. Tisserand (editor) 1993 Gattefossé's aromatherapy: the first book on aromatherapy. CW Daniel, Saffron Walden, p 87