104 Prof. Norton on Molecular Physics, 



envelope, with the attendant discharge on the further side and 

 absorption on the nearer side, is much greater*. 



To obtain a more distinct idea of the entire process of imper. 

 feet conduction, we must take account of jv j. 



a certain resistance which a polarized mo- 

 lecule offers to the flow of aether around it 

 from the negative to the positive sidef. 

 Let «, fig. 7, be a polarized molecule. The 

 centre of repulsion of its electric atmo- 

 sphere will fall at some point o on the 

 plus side of the centre. If we inquire into 

 the effective action of the molecule upon a 

 mass of electric aether posited at s, mid- 

 way between p and n y if the atmosphere 



were not disturbed the centre of effective repulsion would fall at 

 r ; in its supposed polarized condition, therefore, it will lie at 

 some point m intermediate between r and o. The two forces 

 exerted upon s would therefore act in the direction shown in the 

 figure, and their resultant would act from s toward t. It will be 

 readily seen that at all points between p and n, the resultant 

 will have a tangential component directed toward n } and a nor- 

 mal component acting outward on the positive side, and inward 

 on the negative side of the molecule. The density of the elec- 

 tric aether at n should therefore be greater than at p ; and while 

 by its elastic tension it is urged around toward jo, it is resisted 

 by the tangential force just spoken of. And so if the electric 

 aether above n is urged by the repulsion of free electricity on 

 that side of the molecule around toward p, it has to overcome 

 this resistance. It is to be observed that the attractive or com- 



* In the comparison made on p. 426, between the propagation of heat 

 and the propagation of electricity, it is intimated that each is promoted by 

 a polarization of the molecules. This is true only in a limited sense. The 

 circumstances most favourable in general to a conduction of either electri- 

 city or heat are a uniformly dense condition of the interstitial electric 

 aether, which may serve as a medium for the direct propagation of the waves 

 or pulses, and such a condition of the electric atmospheres of the molecules 

 that the resistance developed by any polarization that may ensue shall be 

 comparatively feeble (see next page). When, however, the direct conduc- 

 tive action, by the intervention of the interstitial electric aether, is feeble, a 

 greater facility of polarization on the part of the individual molecules would 

 promote the discharge from molecule to molecule. 



f The terms negative and positive, as here used, have reference to the 

 polarization simply, which is a change in the distribution of the electric 

 aether in the lower portion of the atmosphere. It will be seen in the sequel, 

 that in the upper portions through which the free electricity moves, when 

 a conducting discharge occurs, there will be an excess of electric aether, or 

 a positive state, on the side of the molecule which is negatively polarized, 

 and a deficiency or a negative state on the opposite side. 



