LUMINOUS INSECTS. 545 



ris Latr.) and told him that one of his people, seeing a Jack-6' 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 probable 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 lam- 

 bent flames, mentioned by Beccaria to be very common in some parts of 

 Italy, and the luminous globe seen by Dr. Shaw^ cannot be thus explained, 

 is obvious. These were probably electrical phenomena : certainly not 

 explosions of phosphureted hydrogen, as has been suggested by some, 

 which must necessarily have been momentary. But that the ignis faiuus 

 mentioned by Derham as having been seen by himself, and which he 

 describes as flitting about a thistle-, was, though he seems of a different 

 opinion, no other than some luminous insect, I have little doubt. Mr. 

 Sheppard informs me that, traveling one night between Stamford and 

 Grantham on the top of the stage, he observed for more than ten minutes 

 a very large ignis fatnus in the low marshy grounds, which had every 

 appearance of being an insect. The wind was very high : consequently, 

 had it been a vapor, 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.^ 



' Travels, 2d ed. 334. ■ " Phil. Trans. 1729, 204. 



' 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, Esfj. 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 ignis fatui are caused by luminous insects. George Wailes, Esq., on the 

 other hand, has given in the Entom. Mao. \. 351, the result of his fathers 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, phosphureted 

 or carbureted hydrogen gas), and consequently cannot bean 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. Waile's 

 father, and being luminous all the time. A mass of hydrogen gas anil 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 c^ccept renewed by a fresh supply. In passing the 

 Appenines between Bologna and Florence in 1827, my two sons and myself amused our- 

 selves 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 it is probable that hydrogen gas rises more or less from crevices in the 

 whole adjoining district, there ought to be traveling or flitting lights, if such be possible, we 



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