( 305 ) 
d 
ae Gate) = (oer), = Z 
ny (aOR = ast p a Gay 
while we write 
ac 3 
nt ane 
we find: 
dv 3? fy d 
df (5) aT oo: (ar). Ge. 
pr pT pr pr 
da2/ pr \de® 02?/ pr \O28 
. (5) 
d 
To determine = with xz small we may avail ourselves of the 
v pr 
equation 
Ge Grt Gr) n= 
y = MRT (lol (1—2) Hele} tp 
We put 
where therefore 
If we call 
CAE a=? 
then — 
SE) saat 
