144 IGNIS PATUUS. [Lesson xxm. 



denly startled with the appearance of a spirit wrap- 

 ped up in fire, which kept dancing round him, 

 and dazzled his eyes to such a degree, that he 

 became dismally frightened, and so the fiery spirit 

 led him out of his road, and then left him. This 

 misfortune of the father would be remembered by 

 the child when he arrived at years of maturity, 

 when he would, perhaps, hear several similar 

 tales from other persons, which the credulous 

 youth would look upon as so many corroborating 

 testimonies of the reality of such ghostly appear- 

 ances ; and, of course, the prejudice would be 

 the more rooted in his mind. 



Should any persons who have been thus mise- 

 rably misinformed, peruse these Lessons, I hope 

 they will be quickly convinced that these horrible 

 Jack 6 1 Lanterns are far from having any thing 

 supernatural about them : on the contrary, their 

 cause, and the effects they produce, may be ac- 

 counted for in a very natural and easy manner. 



The meleor vulgarly known by the names before 

 mentioned, is among philosophers called Ignis Fa- 

 tuus : it is chiefly seen about marshes, meadows, 

 and other moist places, also in burying grounds 

 that lie flat and low, and sometimes near dunghills. 

 The appearances of it usually observed, sufficiently 

 evince that it is an ignited vapour: for inflam- 

 mable air has been found to be the most common 

 of all the factitious airs in nature; and as it is 

 known to be frequently produced from the putre- 

 faction and decomposition of vegetable substances 

 in water, with which marshes, bogs, 8cc. abound, 



it 



