258 Prof. J. J. Thomson on the 
We give also the entire series of arrangement of corpuscles 
for which the outer ring consists of 20 corpuscles. 

Number of corpuscles ......... 59. | 60.| 61.| 62.| 63.) 64.) 65.) 66.| 67. 
—— | ————— | —————— | ————— | | --—. 




Number in successive rings...} 20 | 20 | 20 | 20 | 20 | 20 | 20 | 20 | 20 
16 | 16 [16 |: 17.; 17 | 17 | 2 a 
13°) 13.13} 18) 18 | 1S: |) a eels 
8 | 8 | 91 9M) 30) 10) 405) SOs ee 
21° 3) 38 | 88 Oe) al) a oe 






59 is the smallest number of corpuscles which can have an 
outer ring of 20, while when the number of corpuscles is 
greater than 67 the outer ring will contain more than 20 
corpuscles. 
Let us now consider the connexion between these results 
and the properties possessed by the atoms of the chemical 
elements. We suppose that the mass of an atom is the sum 
of the masses of the corpuscles it contains, so that the atomic 
weight of an element is measured by the number of cor- 
puscles in its atom. An inspection of the results just given 
will show that systems built up of rings of corpuscles in the 
way we have: described, will possess properties analogous to 
some of those possessed by the atom. In the first place, we 
see that the various arrangements of the corpuscles can be 
classified in families, the grouping of the corpuscles in the 
various members of the family having certain features in 
common. ‘Thus, for example, we see that the group of 60 
corpuscles consists of the same rings of corpuscles as the 
group of 40 with an additional ring of 20 corpuscles round it, 
while the group of 40 consists of the same series of rings as 
the group of 24 with an additional ring outside, while 24 is 
the group 11 with an additional ring. To continue the 
series for larger numbers of corpuscles, take the curve z=f(y) 
when /(n) is the number of corpuscles that must be placed 
Fic. 2. 




inside a ring of n corpuscles to make it stable. Let Q be 
the point on this curve corresponding to 60 corpuscles, 2. e. 
OP=60, from Q draw QP, inclined at an angle of 135° to 
