DOC.
2
27
where
v
with the
corresponding
subscript
denotes the
constant
velocity
imparted
by a
unit mechanical force
to
one
gram-equivalent
of the
corresponding
ion
in
the
solution.
In
conjunction
with the
boundary
conditions, these four
equations
completely
determine
the
process
taking place,
since
they permit
the
determination of the
five
quantities
dt
dvm
dv
Ti
...
dz
dt dt
uniquely
for all times.
The general treatment
of the
problem
would
entail
great
difficulties,
however,
especially
since
equations
(ß)
are
not
linear
in
the
unknowns.
However,
we are
only
interested in the determination
of t2-t1.
We
therefore
multiply
the
equations
(ß)
successively
by
em1,
-es1,
em2,
-es2,
and
obtain,
when
taking
into
account (a),
where
p
=
RT-
du
v_
e
mi
dv
-
%
^
dz
V. 6
S1
S1 S1
dz
=
0
-
1
wl
%
fflj
v" vn
+
siel
5i
si
1
dt
+
•
Tz
[13]
In
view
of the fact that
dvm
dv
o
dt
-JÜ1.
__A
...
_
dz dz
dz
vanish wherever diffusion
does not
take place,
integration
of this
equation
with respect
to
z
yields
p
=
0
.
Since time is
to
be
considered
as
constant,
we
may
write
dt
-
-
RT{v"
6"
dv
-
V
.€
.
dv
+
V
6
dv
-
V
€
dv
1
%
*1
St
st
m2 m2
m2
s2s2
s9J
V
62
V
m1
mt
%
+ vn
ti
vn
st
sx
st
+
v
el
v
m2 m2 m2
+ v
.e2
v
s2
s2
[14]