297 
becomes evidently (see fig. 2) — on the supposition that the atoms 
2 ] 
@ o ML: P 
Fig. 2. 
P and Q are on an average at rest, and the mutual polarizing 
action of the atoms may be neglected: 
es! 1 1 ; 1 1 
(lez) (ley)? ° (l- 24-2)? t (I—z—y)? 
1 I 1 1 
ue 
CEN Opee) Gee Gea 
when 7 is the mean distance of the atoms, and z the distance of 
the moving atom on the right from the mean position of equilibrium 
(neutral point) QO. If therefore # is positive, the force of M is 
directed towards P. | 
Now the motion of the electrons round P and Q will exhibit 
phase-difference with that of the electron round MM, so that we shall 
have to calculate the mean value for different values of y and 4’, 
retaining the value of wx, that varies periodically with the time in 
the considered molecule M, which we shall, accordingly, not eliminate 
by taking averages. The integral 
on 27 
f= } jk de: Ee =| = ba 
as (lez) Hey) nm ) G 2) asin arg, —asin( 2a 7+) 
has the form | 
een Rep 
ae E ’ 
22%.) (p—asin p)' 
? 
when 22 ed Jw=gp is put. (w is the phase-difference between P 
and M). With a == 90 + p this becomes: 
ator 
Pp 
| ey da 
f= — = ’ 
na (p+acosa)?  (p*—a*)'/s 
_as is easy to derive. Hence we get, performing the same thing with 
the integrals in which y’ occurs: 
