LAWS OF ELECTRIC PHENOMENA. 17 



the parts of the electric fluid repel each other, and 

 the excess in one surface of the glass expels tlfe 

 fluid from the other surface. This kind of action, 

 however, came into much clearer view in the expe- 

 riments of Canton, Wilcke, and ^Epinus. It was 

 principally manifested in the attractions and repul- 

 sions which objects exert when they are in the 

 neighbourhood of electrized bodies ; or in the elec- 

 trical atmosphere, using the phraseology of the 

 time. At present we say that bodies are electrized 

 by induction, when they are thus made electric by 

 the electric attraction and repulsion of other bodies. 

 Canton's experiments were communicated to the 

 Royal Society in 1753, and show that the electricity 

 on each body acts upon the electricity of another 

 body, at a distance, with a repulsive energy. Wilcke, 

 in like manner, showed that parts of non-electrics, 

 plunged in electric atmospheres, acquire an elec- 

 tricity opposite to that of such atmospheres. And 

 JEpinus devised a method of examining the nature 

 of the electricity at any part of the surface of a 

 body, by means of which he ascertained its distri- 

 bution, and found that it agreed with such a law of 

 self-repulsion. His attempt to give mathematical 

 precision to this induction was one of the most 

 important steps towards electrical theory, and must 

 be spoken of shortly, in that point of view. But in 

 the mean time we may observe, that this doctrine 

 was applied to the explanation of the Leyden jar ; 

 and the explanation was confirmed by charging a 

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