An Introduction to Entomology, 1843

William Kirby and William Spence (1843). An Introduction to Entomology; or, Elements of The Natural History of Insects. Vol. II. London: A. Spottiswoode. 1842, 6th ed. pp.340-2

But besides the insects here enumerated, others may be luminous which have not hitherto been suspected of being so. This seems proved by the following fact. A learned friend (Rev. Dr. Sutton of Norwich) has informed me, that when he was curate of Ickleton, Cambridgeshire, in 1780, a farmer of that place of the name of Simpringham brought to him a mole-cricket (Gryllotalpa vulgaris Latr.) and told him that one of his people, seeing a Jack-o'-lantern, pursued it and knocked it down, when it proved to be this insect, and the identical specimen shown to him.

This singular fact, while it renders it probably that some insects are luminous which no one has imagined to be so, seems to afford a clue to the, at least, partial explanation of the very obscure subject of ignes fatui, and to show that there is considerable ground for the opinion long ago maintained by Ray and Willughby, that the majority of these supposed meteors are no other than luminous insects. That the large varying lambent flames, mentioned by Beccaria to be very common in some parts of Italy, and the luminous globes seen by Dr. Shaw (Travels, 2d ed. 334.) cannot be thus explained, is obvious. These were probably electrical phenomena: certainly not explosions of phosphuretted hydrogen, as has been suggested by some, which must necessarily have been momentary. But that the ignis fatuus mentioned by Derham as having been seen by himself, and which he describes as fliting about a thistle (Phil. Trans. 1729, 204), was, though he seems of a different opinion, no other than some luminous insect, I have little doubt. Mr. Sheppard informs me that, travelling one night between Stamford and Grantham on the top of the stage, he observed for more than ten minutes a very large ignis fatuus in the low marshy grounds, which had every appearance of being an insect. The wind was very high: consequently, had it been a vapour it must have been carried forward in a direct line; but this was not the case. It had the same motions as a Tipula, flying upwards and downwards, backwards and forwards, sometimes appearing as settled, and sometimes as hovering in the air.—Whatever be the true nature of these meteors, of which so much is said and so little known, it is singular how few modern instances of their having been observed are on record. Dr. Darwin declares, that though in the course of a long life he had been out in the night, and in the places where they are said to appear, times without number, he had never seen any thing of the kind: and from the silence of other philosophers of our own times, it should seem that their experience is similar.

[Extensive footnote to the previous sentence:] A paper by Richard Chambers, Esq., in the Magazine of Nat. Hist. (New Series, i. 353.), relates several facts observed by the celebrated botanists Mr. James Dickson, and Mr. Curtis, author of the Flora Londinensis, T. Stothard, Esq., R.A. (who was, as before mentioned, a zealous entomologist), his father, Mr. A. Chambers, and Joseph Simpson, a fisherman, at Frieston near Boston, all strongly corroborating the above statements as to the probability that at least some ignes fatui are caused by luminous insects. George Wailes, Esq., on the other hand, has given in the Entom. Mag. i. 351. the result of his father's observations and his own, and has also quoted those of Major Blesson, from Jameson's Edinb. New Phil. Journ. for Jan. 1833, in proof "that the moving ignis fatuus of this country always owes its origin to the spontaneous ignition of gaseous particles" (meaning, I presume, phosphuretted or carbutetted hydrogen gas), and consequently cannot be an insect. Without pretending to deny that these gases may be a cause of stationary ignes fatui, I confess myself quite unable to conceive of a small mass of these inflammable materials "about the size of the hand" moving at the height of "three feet from the surface of the ground" and "for the distance of fifty yards nearly parallel with the road," as in the instance seen by Mr. Wailes's father, and being luminous all the time. A mass of hydrogen gas and its compounds, as is well known, whether large or small, when once inflamed (and if not inflamed it cannot be luminous), burns but for an instant except renewed by a fresh supply. In passing the Apennines between Bologna and Florence in 1827, my two sons and myself amused ourselves the night we slept at Pietramala, in observing the well known miniature volcano of hydrogen gas, near to that place, which has been burning for centuries; but though there, if any where, as is probably that hydrogen gas rises more or less from crevices in the whole adjoining district, there ought to be travelling or flitting lights, if such be possible, we neither saw nor heard of any thing of the kind. On the whole, therefore, the evidence up to this time would seem to be in favour of the supposition that ignes fatui which flit about and travel considerable distances are actually luminous insects as above supposed, however rarely they may have come under the notice of entomologists. In the ignes fatui observed by M. Weissenborn (Mag. of Nat. Hist. N. S. i 553.), which were clearly caused by the explosion of phosphuretted hydrogen, there was "a succession of flashes" extending for perhaps half a mile, but they passed over this distance "in less than a second,"—an appearance entirely different form those leisurely movements mentioned by Mr. Chambers and Mr. Wailes, or that by Mr. Main (Mag. of Nat. Hist. N. S i.549.), in which the farmer who said he had knocked the luminous object down, described it as exactly like a "Maggy long-legs" (Tipula oleracea), the very same insect with which Mr. Sheppard compared the luminous appearance he witnessed. I will conclude this long note with observing that a very strong argument for the possibility of some flying insects being occasionally luminous is afforded by the facts above stated of luminous caterpillars having been within these few years observed for the first time since entomology has been attended to, and that by observers every way competent. If caterpillars so very common as those of Mamestra oleracea may sometimes, though so rarely, be luminous, and if, as Dr. Boisduval suggests, and is very probable, this appearance was caused by disease, it is obvious that flying insects may be also occasionally (though seldom) luminous from disease,—a supposition which will at once explain the rarity of the occurrence, and the circumstance that insects of such different genera, and even orders, are said to have exhibited this phenomenon.

Sean B. Palmer