Electroluminescence 253 



often on a grand scale, knowledge of which goes back to ancient 

 times. In addition to the aurora borealis, there are St. Elmo's fires 

 at the tips of masts or church steeples and glow or brush discharges 

 from objects near the ground in high mountain regions. The glow 

 on rubbing the fur of a cat or on removing silk clothing are exam- 

 ples of electroluminescence, all dependent on certain atmospheric 

 conditions. This glow is often called ignis lambens to distinguish it 

 from ignis fatuus, a light hard to explain. 



The above phenomena, when of cosmic origin, were formerly 

 described as " meteors," since the word meteor was originally used 

 for any atmospheric appearance, although it has a more restricted 

 meaning today. Reference has already been made to Chinese and 

 to classic Greek and Roman knowledge of the aurora borealis, called 

 chasmata by Aristotle, and bolides or trabes by Seneca and Pliny. 

 In addition, Roman soldiers saw " fires " at the end of their pikes 

 and " stars " settle on the masts of ships. These " Stella castores " 

 or " Castor and Pollux " of the Romans, " polydeuces " of the 

 Greeks, together with more gentle displays, the ignis lambens, were 

 observed and recorded by Pliny, Plutarch, Seneca, Caesar, and Livy, 



Every race has had its name for the English St. Elmo's fire or the 

 German St. Elmsfeuer, which appears to be a corruption (through 

 Sant' Ermo) of St. Erasmus, a bishop who was killed in a. d. 304, 

 and became the patron saint of Mediterranean sailors. The French 

 speak of St. Helene's or St. Telme's fire, the Spaniards of St. Helme's 

 fire. On the other hand, Italians refer to the fires of St. Peter and 

 St. Nicholas.^ Called corposants or comazants by sailors, a name 

 which came from the belief of early Portuguese and Spanish voy- 

 agers that the body of the Saint (Cuerpo santo in Spanish) could 

 be seen in the electrical display; a more common term is Corpus 

 Christi lights. 



Space does not permit an extended discussion ^ of the beliefs con- 

 cerning the various phenomena classed as meteors or things of the 

 air, the occasional appearances of the sky, as distinguished from the 

 permanent fixtures— the moon, stars, and planets. Comets were 

 meteors which gave rise to endless discussion, especially concerning 

 the tail which streamed away from the sun. One of the best seven- 

 teenth-century statements on meteors will be found in the Speculum 



' If three lights appear, the third may be called St. Anna or St. Barbara. 



• See Joanne Stierio, Praecepta doctrinae, logicae, ethicae, physicae, metaphysicae, 

 etc., London, 1641, p. 24 of Physicae, dealing with " De meteoris ignis puris "; also 

 Thomas Willsford's Nature's secrets; or the admirable and wonderful history of the 

 generation of meteores (London, 1658) and the Thirteen books of natural philosophy 

 (London, 1661) by Danniel Sennert, Nicholas Culpepper and Abdiah Cole. Book IV, 

 Chap. 1 deals with " Meteors in general " and Chap. 2 with " Fiery meteors." 



