CHAP. II. POLAR FOECB. 19 



ciated with electric force when manifested in its 

 static, or in its dynamic condition, the former as it is 

 manifested in a charged Leyden jar, the latter as it 

 exists in a wire or any conducting medium, when it 

 assumes the so-called current form. In both in- 

 stances, in the static and the dynamic condition, we 

 have the characters of polarity clearly manifested ; 

 a ' duality,' an ' antithetical action,' a ' contrast of 

 properties in a contrast of positions ;' and it is some- 

 what surprising to find Mr. Geove, in 1855, at page 

 152 of his Essay, stating, that "it is difficult to 

 convey by words a definite idea of the dual or 

 antithetic character of force involved in the term 

 polarity," after the clear definition of it given by 

 Paeaday, as far back as 1833, when he speaks of it 

 " as an aads of power having contrary forces exactly 

 equal in amount in contrary directions^." In Whewell's 

 Philosophy of the Inductive Sciences, published in 

 1840, will be found a very interesting chapter, (Book 

 V. on the Idea of Polarity,) in which extremely 

 valuable observations are made in reference to the 

 same point. However important Mr. Geove's views, 

 as published in his Essay, may be considered, and 

 that they possess some value cannot be denied, I 

 still believe that the views advanced by Faeadat, 

 and worked out in his admirable Memoirs, are by 

 far the most philosophic. There is a unity of 

 thought, a firmness of opinion, and a consistency 

 about them which bear the stamp of truth. And 

 ^ Experimental Eesearohes, vol. i. p. 148. 



