Foxfire, also sometimes called "fairy fire", is the bioluminescence created by some species of fungi present in decaying wood. The bluish-green glow is attributed to luciferase, an oxidative enzyme, which emits light as it reacts with luciferin. It is widely believed that the light attracts insects to spread spores, or acts as a warning to hungry animals, like the bright colors exhibited by some poisonous or unpalatable animal species. Although generally very dim, in some cases foxfire is bright enough to read by.
The oldest recorded documentation of foxfire is from 382 B.C., by Aristotle, whose notes refer to a light that, unlike fire, was cold to the touch. The Roman thinker Pliny the Elder also mentioned glowing wood in olive groves.
Foxfire was used to illuminate the needles on the barometer and the compass of Turtle, an early submarine. This is commonly thought to have been suggested by Benjamin Franklin; a reading of the correspondence from Benjamin Gale, however, shows that Benjamin Franklin was only consulted for alternative forms of lighting when the cold temperatures rendered the foxfire inactive.
After many more literary references to foxfire by early scientists and naturalists, its cause was discovered in 1823. The glow emitted from wooden support beams in mines was examined, and it was found that the luminescence came from fungal growth.
The "fox" in "foxfire" may derive from the Old French word fols, meaning "false", rather than from the name of the animal. The association of foxes with such fires is widespread, however, and occurs in Japanese folklore.
In popular culture
In the poem "The Ancient Track" by H. P. Lovecraft fox-fire is seen glowing in field and bog where the narrator is convinced he will find the town of Dunwich.
In the episode "Trapped" of the television series Lassie, Timmy and Boomer look for foxfire to keep girls away from them during Martha Tyson's Halloween Party.
In the episode "Our Town" of the television series X-Files, foxfire appears near where a dead body was found in the woods.
In the Smurfs episode "The Smurf who couldn't say no", Pushover Smurf was instructed to gather foxfire from a marsh for a firefly festival; note that both fireflies' light and foxfire occur due to a single substance, luciferin.
In the episode "The After School Hexer" of the anime Ghost Hunt, foxfire appears in several rooms of the high school in Mai Taniyama's dream.
In the romance novel Foxfire Light by Janet Dailey, a horse and its rider are spooked by the light while riding through the woods in the Ozarks.
In the children's book Rascal by Sterling North, the author describes a phosphorescent stump that gleamed at night with foxfire.
In the song by John Denver, "Foxfire Suite," foxfire is referenced.
In an episode of the American situation comedySmall Wonder, Jamie, Harriet, and Vicki use foxfire to see at night when they get lost in the woods while camping. When the foxfire ceases producing light, Vicki uses her robot power to make her hand glow green, causing a surprised reaction from Harriet. Jamie then must hastily explain to Harriet the glow must be due to Vicki spending too much time operating the microwave oven.