Forces of Electricity: Part II, 337 



common matter to surround it in the form of any number of 

 concentric strata; the major force of the central nucleus upon 

 all the electrical atoms will then vary in some unknown ratio 

 inversely as their distances respectively. Hence an atom of 

 free electricity attracted to the surface of such an electro- 

 sphere by the minor force, being necessarily the most distant 

 atom, and, so far as the equivalent of the common atom is\ 

 concerned, supernumerary, could never become attracted by 

 that common atom ; under such circumstances, therefore, the 

 free atom would exercise no inductive action whatever to 

 cause any portion of the contents of the electrosphere to be- 

 come liberated. 



78. Now let us suppose the preceding case to be repeated, 

 with this only modification, namely, that the outer stratum of 

 the electrosphere by which the electrical equivalent of the 

 common atom is completed were deficient some one or more 

 of the number of electrical atoms requisite to constitute it a 

 perfect shell ; and we shall find the result to be very different. 

 To fix and simplify our ideas, let us imagine the electrical 

 equivalent to be completed by the existence of a single elec- 

 trical atom on the surface of the last perfect stratum of the 

 electrosphere, and an atom of free electricity to be artificially 

 placed against that surface; in such a case two electrical 

 atoms would obviously be at the same distance from the centre, 

 and consequently the more proximate hemisphere of each 

 engage the major force of the common nucleus. 



79. In the next place let there be a second similar electro- 

 sphere in contact with the former one ; the tendency of the 

 two exterior electrical atoms, as also that of the added free 

 atom, under the influence of the minor force, will be to place 

 tiiem all in a triangular position in a plane separating the 

 two electrospheres. Whether in this or any other situation, 

 two of them will be equally held by the major force of the two 

 common nuclei, each of the latter acting on proximate hemi- 

 spheres; the third atom of electricity being retained in con- 

 nection simply by the minor force. 



80. But as in electrical investigations we experiment not 

 with atoms but with masses, we have to modify this view of 

 the positions of the exterior atoms of the electrical equivalent. 

 If a homogeneous body be composed of electrospheres similar 

 to those last imagined (78. 79.), the exterior electrical atoms 

 of the electrospheres, considered generally, will be equidistant, 

 or nearly so, from one another, being equally attracted in 

 opposite directions by the minor force in contiguous electro- 



Phil. Masr. S. 3. Vol. 13. No. 83. Nov. 1838. Z 



