[Feux Follets Near Paris]
Artist unknown. Source: Flammarion, L'atmosphère: météorologie populaire (1888, p.749).

Will-o'-the-wisps are lambent flames seen flickering over marshes and fens, recorded for centuries in many different cultures under many different synonyms. Though often explained as ignited marsh gas, some accounts describe behaviours which contradict this theory.

This page traces the history and theories behind the Will-'o-the-wisp, or the ignis fatuus, "foolish fire", as it's known in Latin.

The Lambent Flame

There was in every hollow
A hundred wrymouthed wisps.
Dafydd ap Gwilym (trans. Wirt Sikes), 1340

The Will-o'-the-wisp has been recorded as flickering over marshy ground since at least the middle ages, as the quote above testifies. In the centuries that followed, dozens of antiquaries have recorded anecdotes and personal accounts of the ignis fatuus, with even Sir Isaac Newton mentioning them in his 1704 opus Opticks. The lights have also been incorporated into modern literature, e.g. Dracula, and have even had a children's television show named after them. The most commonly cited explanation for them is that they're the product of ignited marsh gas: most likely slowly leaking methane whose ignition is triggered by phosphene (also called phosphine or phosphorus hydride). Historical and contemporary accounts of these lights, however, often fly in the face of this explanation given that the lights are often seen to move, and to not emit heat.

Some of their synonyms reveal what cultures thought about them: "treasure lights", of Danish origin, suggests that they are the marking places of treasure; "corpse candles" suggests that they're the souls of the departed; "fairy lights", which now mean quite a different thing, suggest that they're the work of (or indeed are) fairies.

The phenomenon is also inextricably linked with the leading astray of weary travellers into mires. The light was taken to be a lantern or a torch carried by a mischeivous spirit, as is indeed reflected in the name Will-o'-the-wisp itself, which has an etymology of "William of the wisp [of lighted hay]". The man of the lantern was said to play tricks on people, as in the case of the gentleman who was knocked off his horse by the Lantern Man of Horning, Norfolk in the 18th century*.

As quoted by Wilkie (1996), in 1778 William Pryce wrote in Mineralogia Cornubiensis that tinners would use anomalous light forms to find veins of tin: "another way of finding veins [...] is by igneous appearances of fiery coruscations. The Tinners generally compare these effluvia to blazing stars." The westcountry seems to have held the phenomenon in generally high regard, in fact, for Dr. Jonathan Couch (or his son, Thomas Quiller-Couch) quotes a poem* in his History of Polperro that is reminiscent of the practice of using foxfire to guide one back home through forest:

Jack o' the lantern! Joan the wad,
Who tickled the maid and made her mad;
Light me home, the weather's bad.


[Wisp in Mudie's Guide]
Artist unknown. Source: Mudie, A Popular Guide to the Observation of Nature (1836, p.144).

The web is littered with folklore sites made by amateur researchers that contain lists of synonyms for the Will-o'-the-wisp. In most cases, citations and sources for these lists are not given, although Katherine Briggs's Encyclopaedia is possibly a source for many. The following list has been compiled mainly from these amateur web sources, with a sprinkling of names garnered from books and journals. These ought to be cleaned up and made into a table, with citation information added as laboriously and pedantically as possible, but for the time being the unadorned list itself will have to suffice. The list runs to about sixty entries in total, and some sources are noted below.

Britain and Unknown: Billy-wi'-t'-wisp (West Yorks.) (gc: 3); Bob-a-longs; canwll corfe (Wales); corp[se]-candle (Scotland, Lancs., Lincs.); Dead/death-candle (Scot., Somerset); elf-fire (gc: 1,440); Ellylldan (Wales) (gc: 551); fetch candles (gc: 38); fetch lights (gc: 42); foolish fire (gc: 645); Friar Rush with a lantern; friars-lanthorn (Milton) (gc: 37); gealbhan (Devereux) (Scot., tree sparrow*) (gc: 123); Gyl Burnt-tayl (England, flirty female) (gc: 11); Hinky-punk (Briggs's Encyclopaedia) (Somerset and Devon); Hob-and-his-Lanthorn (England); Hobbledy's-lantern (Warwickshire, Worcs., and Gloucs.) (gc: 3); Hob[by]-lantern (Worcs., Herts., East Anglia, Hamps., Wiltshire, and west Wales); ignis fatuus (gc: 11,600); Jack-a-lantern, Jack-o-lantern (from Jack-with-a-lantern); Jacky Lantern; Jenny-burnt-tail (Northants. and Oxfordshire) (gc:30); Jenny-wi'-t'-lantern (Northumbria and North Yorks.); Joan-(in-)the-wad (Somerset and Cornwall); Kit-in-the-candlestick (Hamps.) (gc: 5); Kitty-candlestick (Wiltshire) (gc: 9); Kitty-wi'-the-wisp (Northumberland); Lantern-man (East Anglia); Meg o'th' Lantern (name of a lane in Derbyshire*); Merry dancers (Scotland); Nimble men (Scotland); Peg-a/o-lantern (Lancs.); Peggy-lantern (Lincs.); Peggy wi'th' lantern (Derbs.); Pinket (Worcs.); Spunkie/Spunky (Somerset, Fife); Teine Sith/Tiene Sith or "Fire Faery" (Hebridies, Shetland, and Orkeny) (gc: 43); walking fire; Will-o'-the-wisp, Will-with-the-wisp (Lincs., general use); Will-o'-the-Wykes (Norfolk, Lincs. Cars) (gc: 21); Willy Wisp.

Non-British: Annequin (France); Elbisch Feuer (Germany*); feu follet (France*); feux follets or feu folette (Quebec); flammerole (France); furolles (France); Heerwische (Germany); hitodama (Japan); Huckpoten (Germany); Irrbloss (Sweden); Irrlicht (Germany); Irrwisch (Germany); kitsunebi (Japan); liekkio (Finland); lygtemand (Denmark); Lyktgübbe (Scandinavia); Ruskaly (Russia).

Partial list of sources:

Many of the names associated with the phenomenon include personal names: in the list above we have Billy, Friar Rush, Gyl (possibly), Jack, Jacky, Jenny, Joan, Kit/Kitty (possibly), Meg, Peg/Peggy, and Will/Willy. The oldest dating for the most common phrase, Will-o'-the-wisp, in the OED is from the dramatist John Day's "Law-trickes" (1608). The oldest for ignis fatuus is in William Folke's "A Goodly Gallery (Book of Meteors)" (1563) as "[t]his impression seene on the land, is called in Latine, Ignis fatuus, foolish fire, that hurteth not, but only feareth fooles." Ball Lightning on the other hand is a comparatively modern form: "1857 J. P. NICHOL Cycl. Physical Sci. 431/2 Ball lightnings or globes of fire..move slowly from the clouds to the Earth".

Shakespeare mentions "an ignis fatuus or a ball of wildfire" in Henry IV Part I, Act III. "Somehow this idea got tangled up in people's mind with the Jack-o'-lantern, will-o'-the-wisp, friar's lantern, or ignis fatuus, that mysterious, cool, dancing flame of burning methane sometimes to be seen in marshes. The word wildfire comes from the old Germanic wildfeuer for that phenomenon (modern German prefers Irrlicht or Trugbild)." - Wildfire, Quinion

(Todo: Incorporate "Brenning-drake, Burning candle, Dank Will, Death-fires, Dick-a- Tuesday, Elf-fire, the Fair Maid of Ireland, Friar's lantern, Gyl-Burnt-tail, Mad Crisp, Peg-a-lantern, Puck, Shot stars, Spittle of the stars, Star jelly, a Sylham lamp, Walking fire, Wandering fires, Wandering wild-fire, Sheerie, Ignis Fatuus: Spirit Fire. The Breton Sand Yan y Tad: St. John and the Father is a double ignis fatuus that carries at its finger-ends five lights that spin around like a wheel." - Christine's Faery List: Jack o'Lanterns. Lyktgubbe is mentioned on bruzelius.info.)

E.G.R. in Notes and Queries (2nd S. No 10, Mar. 8, 1856) quotes from Lewis's Welsh-English Dictionary (Carmarthen, 1805) thus: "Hudlewyn. An Ignis fatuus. Will with a wisp, &c. Will with a wisp is more frequent in places unctuous, marshy, and abounding in reeds. They haunt burying-places, places of execution, and dunghills. Some that have been catched consist of a shining viscous matter, like the spawn of frogs, not hot, but only shining; so that the matter seems to be phosphorous, raised from putrefied plants or carcases." In Daniel Silvan Evans's An English and Welsh dictionary from 1858, he has the following entry (p.94): "Ignis fatuus, s. (Ll.) ellylldan, hudlewyrn, hudlewyn, llewyrn, malldan, tân ellyl, tân llwynog".

Bibliography and Historical Accounts

This incomplete bibliography lists, chronologically, some of the mentions of the Will-o'-the-wisp that I've been able to find. I hope to republish as many of the public domain ones as is possible linked from the bibliography. The largest of those reproductions so far is John Brand's report from 1777.

Given the antiquity of most Will-o'-the-wisp reports, probably down in part to encroaching urbanisation and draining of the fens and marshes in the previous few centuries, the linked accounts are all from sources on which the copyright has lapsed.

Summary of the sightings:

Reference Date Location Land Number Colour Longevity
1834 Unknown 1 13th October 1834 Loch of Barbush, nr. Dunblane Loch, murky ex-curling pond From 2 to 6 at the same time Blue During a 1.5 hour period
1839 Overton 1 8th May 1839, 11:30 PM 1/2 miles from Rudham, towards Tatterford Meadow 2 first, then several - More than a few seconds
1855 E.G.R. 1 2nd March 1844? Before 1855 Quy Bottom, Newmarket Road, a few miles from Cambridge Fenny bog 1? - -
1862 Phipson 1 (Blesson) Before 1862 Valley of Gorbitz, Germany? Marshy ground 1 - Hours? Appeared gradually as night fell
1938 Rudkin 1 (A.B., et al.) Before 1938. E.g., between 8 and 10 PM Old Leys Lane and Sallow Holt, nr. Willoughton, Lincolnshire Road, farmland Single light? Like a bicycle lamp. White or Orange? Minutes?
1938 Rudkin 2 (A.B.) Before 1938 Blyton Carrs, Lincolnshire Law land Several? "Redder" (than a bike lamp) -
1938 Rudkin 3 (G.H.) End of summer 1931, before 1938 Cammeringham Top and in a wood at Cammeringham, Lincolnshire Hill, woods 1? - -
1938 Rudkin 4 (G.H.) Before 1938 Fish Pond (field), Harpswell, Lincolnshire Field 1 - -
Reference Altitude Behaviour Sound & Smell Temp. Weather Nomenclature
1834 Unknown 1 Surface Reeling and passing one another, fantastically - - Calm and moist, preceeding heavy shower and wind Ignis Fatuus, Jack wi' the lantern, Will o' the Whisp
1839 Overton 1 2 feet Moving, half circles, 2 or 3 in sync with lightning - - Dense fog, starlit night, vivid lightning, NE wind Will with a Wisp, ignis fatuus
1855 E.G.R. 1 - - - - - Will O' The Wisp, hob o' lanterns, hobby-lanterns, Syleham lamps, lantern-men, lanternman
1862 Phipson 1 (Blesson) Surface Flame-like, marsh gas. Flame receded on approach - Enough to light a piece of paper - Will-o'-the-wisp, ignis fatuus, Jack-o'-lantern, elf-candles
1938 Rudkin 1 (A.B., et al.) 3 feet or so Moved, like a bicycle. Moves steadily, doesn't dance - - - Will o' the Wisp, Peggy with a Lantern, Willie Wisp, Jenny Lantern
1938 Rudkin 2 (A.B.) Close to the ground Move about, dance, like a man carrying a lantern - - - Will o' the Wisp, Peggy with a Lantern, Willie Wisp, Jenny Lantern
1938 Rudkin 3 (G.H.) - Bounding up and down - - It had been a very wet summer Will o' the Wisp, Cammeringham Light
1938 Rudkin 4 (G.H.) - Comes across a field, occasionally seeks a stream - - - Will o' the Wisp, Peggy with a Lantern, Willie Wisp, Jenny Lantern

Notes: Phosphoretted Hydrogen

When did the phosphoretted hydrogen theory of Will-o'-the-wisps originate? It's possible to establish the terminus a quo, the earliest possible date, at 1789 with Lavoisier's discovery of what he described as a "hydruyet of phosphorus, or phosphuret of hydrogen". The earliest terminus ad quem, the latest possible date, I've found so far is from 1806:

In Jane Marcet's 1806 Conversations on Chemistry, in which the elements of that science are familiarly explained and illustrated by experiments, Mrs. B explains to her pupils Emily and Caroline how phosphorated hydrogen gas spontaneously ignites in the atmosphere at any temperature, thereby rendering an optical illusion of dancing specters: "It is thus that are produced those transient flames, or flashes of light, called by the vulgar Will-of-the-Wisp, or more properly Ignes-fatui, which are often seen in church-yards, and places where the putrefaction of animal matter exhales phosphorus and hydrogen gas."

[...] (15) Mrs. Jane [Haldimand] Mercet, Conversations on Chemistry, in which the elements of that science are familiarly explained and illustrated by experiments (London: Longman, Hurst, Rees, and Orme, 1806) vol. 1, p. 99.

Science Fiction and Techno-Gothic Drama, Marjean D. Purinton

This is a remarkably short period of time after the initial discovery of phosphine for it to be applied to the ignis fatuus.

Further Reading Online

There aren't a great many sites with good information about the Will-o'-the-wisp online, but Michael Quinion covered it as one of his weird words, and Wikipedia has a more than passable article about them. Here are some of the more promising resources:


Have you seen some anomalous lights yourself? Do you have some comments on any of the details on this site? If so, please feel free to email me, or send a message using the form. By default all correspondence will be kept in the strictest confidence, but please do give permission to post feedback to this site if you're willing to.

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Sean B. Palmer