CHAPTER XXXIX 



THUNDER AND THE LIGHTNING-ROD 



T) Y their clever researches, Franklin, de Romas, 

 Jj and many others have revealed to us the na- 

 ture of lightning ; they have taught us, in particular, 

 that when its quantity is small, it leaps to meet one's 

 finger in bright, crackling sparks, without danger to 

 the experimenter, and that all bodies containing it 

 attract neighboring light substances, just as the kite- 

 string attracted the straws in the experiment made 

 by de Romas, and just as sealing-wax and rubbed 

 paper attract the down of feathers. In short, they 

 taught us that electricity is the cause of thunder. 



"Now there are two distinct kinds of electricity, 

 which are present in equal quantities in all bodies. 

 As long as they are united, nothing betrays their 

 presence; it is as if they did not e.xist. But, once 

 separated, they seek each other across all obstacles, 

 attract each other, and rush toward each other with 

 an explosion and a flash of light. Then all is in 

 complete repose until these two electric principles 

 are again separated. The two electricities, there- 

 fore, supplement and neutralize each other; that is 

 to say, they form something invisible, inoffensive, 

 inert, that is found everywhere and is called neutral 

 electricity. To electrify a body is to decompose its 

 neutral electricity, to disunite the two principles 



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