18 HISTORY OF ELECTRICITY. 



plate of air, and obtaining a shock from it, in a 

 manner which the theory pointed out. 



Before we proceed to the history of the theory, 

 we must mention some other of the laws of pheno- 

 mena which were noticed, and which theory was 

 expected to explain. Among the most celebrated 

 of these, were the effect of sharp points in conduc- 

 tors, and the phenomena of electricity in the atmo- 

 sphere. The former of these circumstances was one 

 of the first which Fr'anklin observed as remarkable. 

 It was found that the points of needles and the like 

 throw off and draw off the electric virtue ; thus a 

 bodkin, directed towards an electrized ball, at six or 

 eight inches distance, destroyed its electric action. 

 The latter subject, involving the consideration of 

 thunder and lightning, and of many other meteor- 

 ological phenomena, excited great interest. The 

 comparison of the electric spark to lightning had 

 very early been made; but it was only when the 

 discharge had been rendered more powerful in the 

 Ley den jar, that the comparison of the effects be- 

 came very plausible. Franklin, about 1750, had 

 offered a few somewhat vague conjectures 13 respect- 

 ing the existence of electricity in the clouds, but it 

 was not till Wilcke and ^Epinus had obtained clear 

 notions of the effect of electric matter at a distance, 

 that the real condition of the clouds could be well 

 understood, In 1752, however 14 , D'Alibard, and 

 other French philosophers, were desirous of verify- 



13 Letter v. Franklin, p. 107. 



