﻿Aspects of the Is eon Spectrum, 207 



r = radius of orbit described by the two inner electrons ; 

 coi = angular velocity about YY' ; co 2 = angular velocity 

 about ZZ' ; &> 3 = angular velocity about XX'. I = I length 

 side of electron cube ; s = ^ surface diagonal of the electron 

 cube; c = ^ diagonal of cube, 'a' and i V are of course 

 functions of ' c,' and if the latter is known, then ' 5 ' and 

 ' I ' can be found, m — mass of an electron when its velocity 

 is small compared with that of light. * 



From these equations it was shown by the author that 

 an equation involving only ' r,' ' c/ ' /,' and ' s ' could be 

 found. In the paper mentioned, '/' and ' s' were not 

 expressed as functions of ' c,' but expressing them as such, 



since 1 = — — and s= — ~— , we obtain the equation 

 o o 



4-34 r-h'Dllc f, 2-308c-) 



r + 'Dile r . Z'dVSc 1 



" L0'+'577c) 2 + -667c 2 ;p ) r J 



r-'577c f 2'308c^ 5^ 



[(r--577(') 2 + -667c 2 ] 3/2 1 r J + r 



. (V.) 



In a recent article it was shown by Prof. W. L. Bragg * 

 that the diameter of the neon atom could be found by an 

 inspection of the diameters of the atoms of elements whose 

 atomic numbers were near that of neon. It is impossible to 

 measure the radius of the neon atom directly, since it forms 

 no chemical compounds. The value obtained was very much 

 smaller than that found by gas measurements, and the former 

 is considered by Bragg to be the distance between the elec- 

 trons in the atom — that is to say, is equal to ' 2c/ The value 

 obtained by Chapman f from gas measurements is, however, 

 the diameter presented by the molecule when in collision 

 with other molecules. The difference is due to the fact 

 that in molecular collisions in the gaseous state the outer 

 electrons of the molecules do not come into contact}:. 

 Using Bragg's value we have 2c = l'30 X 10~ 9 cm., and on 

 substituting in equation (V.) we have a means of obtaining 

 the fundamental value of l r.' 



An inspection of equations (II.) and (III.) shows at once 

 that o) 1 = o) 2 and equations may be obtained for co 1 and co 3 . 



* Phil. Mag. vol. xl. p. 169. 



t Trans. Roy. Soc. A. vol. 216, p 279. 



X Rankine, Proc. Roy. Soc. vol. xcviii. p. 360. 



