309 
which yields 2=—=0 at ¢=0. It will now further entirely depend 
on the value of the phase-difference @ (the difference of time be- 
tween the fictitious passage of the electron through the nucleus, and 
of M through Q), what type of path of periodic movement will be 
obtained. 
1. If 0 =0 (the electron passes (fictitiously) the nucleus from the 
right towards the left exactly when Jf moves in O towards the 
right in the direction of P), we get: 
t 
uu, + gen, (aa cos) == AEK 
jk 
The value of w (see fig. 3) will now always be >>u,, so that 
there can only be question of its becoming 0 on collision (-—z= 2a). 
O=o 
t 
' 
5 
o 
A 
AIT Z J 
“eA +a aT ar 
Fig. 3. 
The molecule M will then approach P so closely till the electron 
has assumed the position close to «= — a, in consequence of which 
the repulsive force becomes very great. Then the velocity becomes 
=0 in an exceedingly short moment, and the molecule is thrown 
Fig. 3a. (Gases). 
back (in A, close to t= */,7’). When the molecules are far enough 
from each other (gases), several periods may pass before this collision 
at last sets in (Fig. 3a). The increasing values of the amplitudes in 
Fig. 3a must of course be attributed to the increasing influence of 
z, through which the action exerted becomes stronger and stronger 
(ef. also the calculations in § 10). This gives also rise to the devia- 
tions of the course, following from (8), close to the collision (repre- 
