— Meeor sin 2 + ma) 2 r sin 2 6 = 0, 



2b'S 0;i the Structure of the Atom, 



M sin #, radial equilibrium ensues if 

 Ae 



and tangential equilibrium ensues if 



N? = nico, 



or if = or = 7r/2. If at # = 7r/2 there is equilibrium, the 

 former condition becomes 



A^ 



-g- 4- mo) 2 r= Mewr= H-tewr, 



as already found, and the radial force is one of repulsion at 

 any other value of 6 with the same r. Whenever (o slows 

 down sufficiently by radiation, expulsion follows. It is quite 

 possible to arrange equilibrium at a value of other than 

 77-/2, but continuous decrease of w would then occur with 

 continuous increase of 6. 



§ 5. Addendum. 



In order to account specially for the law r s observed to 

 regulate the expulsion of electrons by photoelectric action or 

 by Rontgen rays, the requisite law of electrostatic repulsion 

 has been adopted, and no special case of electric attraction 

 has been considered in conjunction with the electromagnetic 

 action. A paper by Professor Conway has appeared in a 

 recent issue (Dec.) of the Philosophical Magazine, in which 

 results of electrostatic attraction have been considered, and 

 a very remarkable mode of preserving constancy of period 

 has resulted, while emission of radiation may proceed by 

 quanta. Such emission does not occur in the cases considered 

 above, but there is no experimental basis necessitating pro- 

 vision for this condition in bright line emission. If such a 

 basis arose electrostatic attraction might have to be postulated 

 in the regions of stable revolution of electrons. 



The fundamental difference between Professor Conway's 

 scheme aud the above one lies in the origin of stable regions. 

 He seeks it in nodal oscillations of the atom, that is in the 

 qualities which determine atomic vibrations. In the above 

 treatment, it is sought for in the qualities of electricity or 

 aether which determine, it may be, loci of permanent strain, 

 or, in any case, features of permanent atomic structure. 



