of the Electrical Terms Intensity and Tension, 511 



is greater than from the series of small ones, inasmuch as there 

 is less obstruction in the way of discharge from a series of four 

 large plates than from a prolonged series of thirty-six small 

 plates, whilst, on the other hand, there will be a greater quantity 

 on the terminating small plates of the long series, and conse- 

 quently a more intense action in those plates. Hence it has 

 been said that heating effect depends on quantity, and chemical 

 action on intensity. 



12. The term " tension " is more especially applicable to the 

 polarized condition of accumulated electric particles, or to the state 

 of the particles of any dielectric medium intermediate between a 

 positive and negative surface, as, for example, to the particles of 

 the glass of an electrical jar interposed between its inner and 

 outer coatings, or to the particles of the atmosphere or other 

 dielectric medium intermediate between a positive and negative 

 surface. These particles, as Faraday has shown, assume a pecu- 

 liar polarized state, which state, when the electrical accumula- 

 tion upon the opposed conducting surfaces exceeds a given 

 amount, they can with difficulty maintain, in which case the 

 electrical strain upon them becomes so great that they return 

 with violence to their normal condition, so that discharge ensues 

 through the intermediate dielectric medium. This electrical 

 strain or condition to which the particles are thus subject may 

 hence be fairly characterized by the term tension; and therefore 

 this term may be denned to be the constrained state of the par- 

 ticles of any electrical accumulation, or of any dielectric medium 

 interposed between two oppositely charged surfaces ; whilst the 

 term intensity applies to the quantity of electricity at a given 

 point of a charged surface acting upon the electrometer. 



In accordance with these views of tension and intensity, we 

 find that whilst intensity (that is to say, the electrometer indi- 

 cation (1)) is as the square of the quantity, electrical tension, or 

 disruptive force, as measured by a Lane's striking electrometer, 

 is simply as the quantity. 



13. The distribution of force alluded to (9) in the charge and 

 discharge of the electrical jar, admits of geometrical representation 

 in a way calculated to elucidate in a satisfactory manner the 

 precise condition of this ques- 

 tion. A e f 9 b 



Let the line AC in the 

 annexed diagram move for- 

 ward parallel to itself upon 

 the line C D, and generate the 

 equal rectangular spaces A m, 

 en, fo,gJ) ; then these spaces 

 may stand for and represent 



