572 THE INTELLECTUAL RISE IN ELECTRICITY. 



It is needless to discuss Freke's supposition, because, 

 almost immediately following him, came Winkler, 1 with a 

 theory still more highly elaborated, in which the like- 

 nesses between electricity and lightning were pointed out 

 with remarkable detail. He demands "whether the 

 shock and spark of strengthened electricity is a kind of 

 thunder and lightning," and proceeds to answer the query 

 at length. 



The lightning-stroke, he explains, is enormously more 

 powerful than the electric spark; but that is no proof that 

 they are of different natures. Even if a man had never 

 seen fire and explosion except from a cannon, would he 

 fail to recognize, in the discharge of a boy's pistol, the 

 same effects, but in weaker degree? The lightning- 

 stroke and the electric spark are alike in rapidity. Add 

 together the detonations of many electric sparks, and the 

 noise may be augmented. So in the lightning, which 

 may consist of an immense number of such sparks, the 

 combined explosion of all causes the sound of thunder. 

 Lightning moves through the air in a zigzag or serpentine 

 path; so does an electric spark in passing over moist 

 insulators. The lightning-flash is sometimes multiple 

 like a collection of rockets; so is the discharge between 

 iron cylinders. The lightning-flash will lay hold of solid 

 bodies and melt them even when enclosed and without 

 injuring the envelope (Cardan's coins melted in their 

 purse); the spark will reach non-electrics, through insu- 

 lators. It will pass through one's clothes, or electrify 

 metal enclosed in paper. True we cannot burn houses 

 and trees, or kill men and animals, by the spark; but not 

 all kinds of lightning do this, hence the spark may re- 

 semble some particular variety. 



Winkler's conclusion is that the atmosphere contains 

 matter in great quantities, derived from exhalation and 

 evaporation, going on at the earth's surface. It abounds 



1 Winkler: Die Starke der Electrischen Kraft des Wassers in Glaserueii 

 Gefassen, etc. Leipsic, 3746, c. x. (Preface dated Sept. 6, 1746.) 



