( 55 ) 
molecular distances, and the centre of which is occupied by the mole- 
cule to be considered. I denoted by 
x, 9, 3 
the components of the electric force at the centre of the sphere, in 
so far as it is due to the molecules within the surface, by 
pn ah Ve. pe 
the components of the elastic force by which the ion is driven back 
to its position of equilibrium, and by 
Me ) My ) 
Me, 
three auxiliary functions, satisfying the equations 
\ 
1 3? 
(a <3) Me =—4 M‚ ’ 
CRT: 
1 d2 
(A = =a) m, =—40M,, (5) 
1 9? 
— EE NM. ——4 M. 
(a 3 =) z ee 
In these the velocity of light in the acther is again represented 
by v. Finally, I found for the first of the three equations of motion ') 
dex A ae 
B tl EER LE 20M 
7 enen Go aly oma 
+ ve bee Bie Oy Cs Ae ne pie 
Ou? dx dy Ow de v2 ot? 
[aa vtefo tek. : (6) 
The term 
e” dx 
vd” 
which eorresponds to the damping of the vibrations by radiation, 
was shown to be so small that it may be negleeted. 
If, in (6), we replace some of the terms by their mean values, 
we shall find after division by e and after replacing © by M,, mul- 
tiplied by a constant, 
IL cd, § 128, 
Proceedings Royal Acad, Amsterdam. Vol, IL, 
