474 Dr. R. Hare's Objections to the Theories severally of 



sectional area*, and less upon the extent of surface. The re- 

 ciprocal repulsion of the siniilarl}' polarized aethereal particles 

 must tend always to make them seek the surface, but at the 

 same time their attraction for the £)ethereo-ponderable particles 

 composing the wire has the opposite eifect, and tends to 

 derange these from their normal polar state of quiescence. 

 Commensurate with the extent in which this state is subverted, 

 is the resulting heat, electrolytic power, and electro-magnetic 

 influence. The phsjenomena last mentioned are, however, 

 secondary effects consequent to theparticipation of the eethereo- 

 ponderable matter in the undulations resulting from the sta- 

 tical discharge. 



44. Such effects, making allowance for the extreme minute- 

 ness of the time occupied by the process, are probably in all 

 cases proportional to the degree in which the ponderable 

 matter is affected, up to the point at which it is dissipated by 

 deflagration ; but the duration of a statical discharge being 

 almost infinitely minute for any length of coil which can con- 

 veniently^ be subjected thereto, the electro-magnetic and other 

 effects of a statical discharge are not commensurate with the 

 intensity of the affection of the wire. 



45. There is, in fact, this additional reason for the diversity 

 between the electro-magnetic power of a statical discharge, as 

 compared with that of the voltaic series : any wire which is 

 of sufficient length and tenuity to display the maximum power 

 of deflagration by the former, cannot serve for the same pur- 

 pose in the case of the latter. Moreovei', the form of a helix 

 closely wound, so that the coatings may touch, which is that 

 most favourable for the reiteration of the magnetic influence 

 of the circuit upon an iron rod, cannot be adopted in the case 

 of statical discharges of high intensity, since the proximity of 

 the circumvolutions would enable the jethereal waves, notwith- 

 standing the interposition of cotton or silk, to cross superfi- 

 cially from one to the other, parallel to the axis of the included 

 iron, instead of pursuing the circuitous channel afforded by 

 the helix with the intensity requisite to the polarization of the 

 ponderable atoms. 



The extreme diversity, as respects striJdng distance, between the 

 direct effects of Frictionat Elcctricitij and those directly 

 arising from Galvanic Reaction. 



46. The intensity of the excitement produced by different 

 electrical machines, is estimated to be as the relative lengths 

 of the sparks which proceed from their prime conductors 



* The sectional area of a conductor is the area of the superficies which 

 would be exposed by cutting it through at right angles to its axis. 



