THE WILL-O'-THE-WISP. 283 



informed Dr. Kirby that when he was curate of Ickleton, in Cambridgeshire, in 

 1780, a farmer of that place, of the name Simpringham, brought him a mole- 

 cricket {Gryllotalpa vulgaris), and told him that one of his people, seeing a Jack- 

 o'-Lanfern, struck at it and knocked it down, when it proved to be the insect in 

 question. Mr. Main ("Mag. of Natural History," n. s., i., p. 549) was told by 

 a farmer that he had encountered and knocked down the luminous object, which 

 he described as being exactly like a "maggy longlegs" {Tipula oleracea), an in- 

 sect, we must add, especially abundant in boggy and marshy lands. Dr. Dere- 

 ham, the opponent of the insect theory ("Phil. Trans.," 1729, p. 204), describes 

 an Ignis fatuus which he had personally witnessed as flitting about a thistle — a 

 very likely action for an insect, though unlikely for a volume of inflammable gas 

 or for an evil spirit. Mr. Sheppard informed Dr. Kirby that when travelling one 

 night from Stamford to Grantham, on the top of a stage-coach, he observed "for 

 more than ten minutes a very large Ignis fatuus in the low marshy grounds, which 

 had the same motions as a Tipula, flying upward and downward, backward and 

 forward, sometimes as settled, and sometimes as hovering in the air." It is 

 remarked that in this case the wind was very high, so that a vapor would have 

 been carried forward in a straight line, which was not the case. We are well 

 aware that the insect-theory is not free from difficulties. Thus the question at 

 once arises, Why is this phenomenon so rare ? It is also to be asked whether the 

 light given off by insects is sufficiently strong to be visible at such distances as the 

 Wisp is said to have been ? 



The orthodox theory at the present day — that of spontaneously inflammable 

 gases, hydrogen phosphide, marsh-gas, and possibly hydrocarbons given off by 

 decomposing animal or vegetable matter, is open to even more formidable objec- 

 tions. The presence of the spontaneously inflammable variety of hydrogen phos- 

 phide has never yet, we believe, been analytically demonstrated among the gas- 

 eous matter given off from marshes, pools, and cemeteries. 



In Brande's "Dictionary of Science, Literature, and Art," (ii., p. 191), the 

 Wisp is ascribed to "the issue of marsh-gas from the earth. This gas, being 

 ignited either accidentally or intentionally, continues to burn with a flame suffi- 

 ciently luminous to be well seen at night." The writer admits, at the same time, 

 that no natural production of spontaneously inflammable gas has ever been ob- 

 served. Dr. Phipson gets over the difficulty of ignition by assuming that the gas 

 given off" consists of marsh-gas through which a small proportion of hydrogen 

 phosphide is diffused. But an emission of inflammable gases from the earth or 

 the water, however ignited and however composed, will not account for the phe- 

 nomena in the majority of cases on record. In proof of this let any one perform 

 the simple experiment of stirring up the mud at the bottom of a dirty ditch or 

 pond, and ignite the marsh-gas given off by means, say, of a piece of taper fixed 

 at the end of a fishing-rod. The gas will burn immediately over the surface of 

 the ditch or swamp, but the flame will not travel away for considerable distances, 

 overleaping hedges, stiles, trees, or buildings, or playing over thistles. Further, 

 it is found that the Wisp is most common in calm, fine weather, when the barom 



