Mr. C. Tomlinson on the Ignis Fatuus, 467 



sionally seen in marshy places and churchyards. The 

 phenomenon has been frequently described, but it has been 

 observed so rarely in favourable circumstances by scientific 

 men, that there is no satisfactory explanation." The theory 

 that the meteor is due to ignited marsh-gas is dismissed as 

 untenable, because the gas does not ignite spontaneously. 

 The more plausible suggestion that it is due to phosphuretted 

 hydrogen, which ignites on contact with oxygen, is also 

 rejected, on the ground that a German observer, named List, 

 " passed his hand through the luminous appearance, and felt 

 no warmth ;" while another German, named Knorr, " held the 

 metal-tip of a walking-stick in the flame of a fixed ignis 

 fatuus . . . for a quarter of an hour, but the metal was not 

 warmed.''' 



References to these observations are not given ; but the 

 luminous appearances were probably not gaseous, but elec- 

 trical, as was also the meteor, which was seen to " bound over 

 the country like a ball of fire for half an hour at a time." 



The scientific reader cannot fail to see that these notices in 

 works of so much pretension, and of such recent dates, are 

 quite unworthy of their fame. It is also curious to notice 

 how the descriptions of earlier writers, with their ignorance 

 of gases and imperfect knowledge of electricity, have stimu- 

 lated the timid doubts of the modern compiler. One example 

 from an old writer, and in many respects an admirable one, 

 may here be quoted, namely, Dr. Van Musscbenbroek, Pro- 

 fessor of Mathematics and Philosophy in the University of 

 Leyden*. In his Latin treatise on Natural Philosophy, vol. ii. 

 page 291, is the following paragraph : — 



" § 1329. Wandering fires, or Ignes Fatui, are of a round 

 figure, in bigness like the flame of a candle, but sometimes 

 broader, and like bundles of twigs set on fire. They some- 

 times give a brighter light than that of a wax candle, at other 

 times more obscure, and of a purple colour. When viewed 

 near at hand, they shine less than at a distance. They wander 

 about in the air, not far from the surface of the earth, and are 

 more frequent in places that are unctuous, muddy, marshy, 

 and abounding with reeds. They haunt burying places, 

 places of execution, dunghills. They commonly appear in 

 summer, and at the beginning of autumn. But in the country 

 about Bononia, they are seen throughout the whole year in a 



* This work was written in Latin, and was first published in 1726 ; 

 it was reprinted in 1734, and again in 1762, each time with considerable 

 augmentations. It was translated by John Colson, M.A., and F.E.S., 

 Lucasian Professor of Mathematics in the University of Cambridge, and 

 was printed for J. Nourse at the Lamb, without Temple Bar, 1744. 



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