Nature of Dielectric Capacity. 19 



is to an ordinary piece of matter, it is a unit of structure. 

 In "The Electric Origin of: Molecular Attraction" (Phil. 

 Mag. [6] xvii. 1909,, p. 657) it is suggested, with the aid of 

 diagrams, that in matter contiguous molecules adjust their 

 axes so that these form axial lines, along ench of which the 

 axes are similarly directed, while the axial lines are alter- 

 nately oppositely electrized. This arrangement is one of 

 minimum electric potential energy and causes each molecule 

 to attract its six nearest neighbours with repulsions and at- 

 tractions beyond these six tending towards an average null 

 effect At the same time it gives no electric moment to any 

 ordinary piece of matter, the sum of the electric moments of 

 all the molecules being nothing. In the atom the chief 

 difference from this state of affairs is that the cohering con- 

 stitutive pairs have their electric axes similarly directed to 

 the extent required to give the whole atom its characteristic 

 electric moment es. This leads naturally to the conception 

 of chains of pairs of electrons, the electric axes of all the 

 pairs being similarly directed along the chain. Let us make 

 a diagram of two such chains symmetrically situated with 



Fi-. 1. 



# 



# 

 b 



# t 



A 



# 



b 



b 





it 



# 



b> 



B 



L# 



b H 



. h 



regard to the electric axis of the whole atom, this axis being 

 denoted by AB. The two chains being electrized in the 

 same direction, on the average that of AB, repel one another. 

 It seems to be the function of the special electron pair placed 

 at AB to attract both of these repelling chains and to hold 

 them in position. The special pair acts like a keystone to 

 all the arches of the constitutive pairs of electrons. 



It appears then that the cohesion of the molecules of an 

 ordinary piece of matter is the result of the action at more 

 distant range of the same electric forces which cause the 



02 



