78 MR. J. P. JOULE ON THE LIFE AND WHITINGS 



style of composition and his comprehensive view of the elec- 

 trical agent, will be read with interest. — " Thus, ladies and 

 gentlemen, I have, as far as this short course of lectures 

 would admit, endeavoured to illustrate the principles of mag- 

 netism, and their connexion with electricity. I have shown 

 you by a series of selected experiments, that there is not only 

 a reciprocal action exercised by those mysterious powers upon 

 each other ; but, by their agency, some of the most wonder- 

 ful and important phenomena of nature are produced. 



" The electric fluid is so universally diffused throughout 

 every part of nature's productions, that every particle of cre- 

 ated matter, both animate and inanimate, which has hitherto 

 been contemplated by the philosopher, is full of this surpriz- 

 ingly animated elemental fire. 



" In regions far above the surface of the earth, where the 

 air is much attenuated and so far thinned, near to the utmost 

 verge of the atmosphere, as to become a conducting medium, 

 the electric element plays its quivering streamers and spark- 

 ling corruscations in the beautiful aurora of the north. Some- 

 times this rare — this fascinating phenomenon is exhibited in a 

 steady glowing arch of light ; whilst at others, it expands its 

 dancing network in transient display over the whole concave 

 of the visible heavens. 



" At altitudes less elevated than those which form the 

 grand theatre for the display of the aurora borealis, the elec- 

 tric discharges become more compact, and shoot slanting 

 downwards, on bright serene evenings, those beautiful gleam- 

 ing orbs of meteoric light, which, from ancient custom, are 

 still called falling stars. 



w Still less elevated in the atmosphere the big black clouds 

 swell with the electrical element, until bursting from its aerial 

 walls it discharges itself into space, in all those grand, magni- 

 ficent, and splendid forms of lightning, with their tremendous 

 peals of thunder, so frequently displayed in most countries 

 during the transient rage of a majestic summer's storm. 



