
Structure of the Atom. 255 
the circumference of the ring in which it is situated, and the 
rings are so arranged that those which contain a large number 
of corpuscles are near the surface of the sphere, while those 
in which there are a smaller number of corpuscles are more 
in the inside. 
If the corpuscles, like the poles of the little magnets in 
Mayer’s experiments with the floating magnets, are con- 
strained to move in one plane, they would, even if not in 
rotation, be in equilibrium when arranged in the series of 
rings just described. The rotation is required to make the 
arrangement stable when the corpuscles can move at right 
angles to the plane of the ring. 
Application of the preceding Results to the Theory of the 
Structure of the Atom. 
We suppose that the atom consists of a number of cor- 
puscles moving about in a sphere of uniform positive electri- 
fication: the problems we have to solve are (1) what would 
be the structure of such an atom, z.e. how would the cor- 
puscles arrange themselves in the sphere; and (2) what 
properties would this structure confer upon the atom. The 
solution of (1) when the corpuscles are constrained to move 
in one plane is indicated by the results we have just obtained— 
the corpuscles will arrange themselves in a series of concentric 
rings. This arrangement is necessitated by the fact that a 
large number of corpuscles cannot be in stable equilibrium 
when arranged as a single ring, while this ring can be made 
stable by placing inside it an appropriate number of cor- 
puscles. When the corpuscles are not constrained to one 
plane, but can move about in all directions, they will arrange 
themselves in a series of concentric shells; for we can easily 
see that, as in the case of the ring, a number of corpuscles 
distributed over the surface of a shell will not be in stable 
equilibrium if the number of corpuscles is large, unless there 
are other corpuscles inside the shell, while the equilibrium 
can be made stable by introducing within the shell an appro- 
priate number of other corpuscles. 
The analytical and geometrical difficulties of the problem 
of the distribution of the corpuscles when they are arranged 
in shells are much greater than when they are arranged in 
rings, and I have not as yet succeeded in getting a general 
solution. We can see, however, that the same kind of pro- 
perties will be associated with the shells as with the rings; 
and as our solution of the latter case enables us to give 
definite results, I shall confine myself to this case, and 
endeavour to show that the properties conferred on the 
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