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cloth as a screen ; on doing which I was able to singe paper, which 

 became brown coloured, and covered with viscous moisture. I next 

 used a narrow slip of paper, and enjoyed the pleasure of seeing it 

 take fire. The gas was evidently inflammable, and not a phos- 

 phorescent luminous one, as some have maintained. But how do 

 these hghts originate? After some reflection I resolved to make 

 the expernnent of extinguishing them. I followed the flame ; I 

 brought it so far from the marsh, that probably the thread of con- 

 nexion,^ if I may so express myself, was broken, and it was 

 extinguished. But scarcely a few moments had elapsed, when it 

 was agam renewed at its source (over the air-bubbles), without my 

 being able to observe any transition from the neighbouring flames, 

 many of which were burning in the valley. I repeated the experi- 

 ment frequently, and always with success. The dawn approached, 

 and the flames, which to me appeared to approach nearer to the 

 earth, gradually disappeared. 



" On the following evening I went to the spot, and kindled a 

 fire on the side of the valley, in order to have an opportunity of 

 trying to inflame the gas. As on the evening before, I first extin- 

 guished the flame, and then hasfened with a torch to the spot from 

 whence the gas bubbled up, when instantaneously a kind of 

 explosion was heard, and a red light was seen over eight or nine 

 square feet of the surface of the marsh, which diminished to a 

 small blue flame, from two and a half to three feet in height, that 

 continued to burn with an unsteady motion. It was, therefore, no 

 longer doubtful that this Ignis Fatuus was caused by the evolution 

 of inflammable gas from the marsh. 



"In the year 1811 I was at Malapane, in upper Silesia, and 

 passed several nights in the forest, because ignes fatui were 

 observed there. I succeeded in extinguishing and inflaming the 

 gas, but could not inflame paper or thin shavings of wood with it. 

 In the course of the same year I repeated my experiments in the 

 Kouski in Poland. The flame was darker coloured than usual, but 

 I was not able to inflame either paper or wood shavings with it ; 

 on the contrary their surface became speedily covered with a viscous 

 moisture. In the year 1812 I spent half a night in the Eubenzahl 

 Garden, on the ridge of the Riesengebirge, close on the Schneekoppe, 

 which constantly exhibits the Will-with-the-Wisp, but having a, 

 very pale colour. The flame appeared and disappeared, but was 

 so mobile that I could never approach sufficiently near to enable 

 me to set fire to anything with it. 



