302 
In consequence of the so much smaller distance of the molecules, 
the action has in many cases become as much as 80-times greater. 
It appears from the above calculations that at low temperatures, 
in which case 7 approaches to 2a, the terms without # can very 
well be omitted, so that we then might write, putting z every where = 0: 
jk WE | ls ne aie Jel La | 1 fon 
loQaje? | (+)? (le) ((l—a)?—a?)"2 (le) |’ 
in which the 4st term predominates ata = — a, the datz — + a. 
Though we may now write: 
di ed 1 1 4 ij 1 1.Q Je 2 ML 
dt? m| de V(l+2)?—a*® le du VEE a l—x\ | mdz’ 
the direct integration of this equation is impossible. For, since 
. : 3 his t 
“x—=asing (in which p is in general = 22 7 + 0, because at 
the beginning of the motion of M through O towards P(t=0, 
when M in O) the electron need not necessarily at the same time 
be in the position «= 0), we get: 
dze er EH) & dL P2298 ec ab 
dm dt de  m dt acos (22t/T'+ 6) <a gy dt’ 
and evidently nothing can be done with this differential equation 
— on account of the complicated form of L, while Va?—«? can 
be substituted for a cos p. 
Hence nothing remains but making the expression (1°) or (1%) 
integrable by expansion into series. 
§ 11. Expansion into Series for F. 
l—z 1 
(2 — ays (a) 
OREO) ex (80 0-14 
Vil aa deg 
and then differentiate the result with respect to z, which is easier. 
We then get: 
Instead of e.g. we shall expand 
1 1 eet 1 \ ' Peas ; zis 
Me ba Ore 8 
a 2\=! 
PERL a ee 
For the expression between {} we may write by joining corre- 
sponding terms: 
