DOC.
1
3
I
proceeded
from
the
simplest assumptions
about the
nature
of molecular
attraction forces
and examined
their
consequences
regarding
their
agreement
with
experiment.
In this
I
was
guided
by
the
analogy
with
gravitational
[6]
forces.
Let
thus the relative potential of
two
molecules
be
of the
form
P
=
^
-
CyC^-^r)
,
where
c
is
a
constant
characteristic of
the molecule in
question, and
Q(r)
is
a
function of their distance that
does not
depend on
the
nature
of the
molecules.
We
assume
further that
[7]
n n
*
I
l
cacß
0=1
M
is the
corresponding expression
for
n
molecules. In the special
case
in
which
all molecules
are
alike,
this
expression becomes
n n
ic2
I I
•
o=l
ß=l
We
further
make
the
additional
assumption
that the
potential of the molecular
forces
has
the
same magnitude
it
would
have
if the
matter
were homogeneously
distributed in
space;
this
is,
however,
an
assumption which
we
should
expect
to
be
only approximately
correct.
Using
it,
the
above expression
converts
to
P
=
P
~
U2fP
00
fr.«frV(rrf
rfr.)
[8]
where
N
is the
number
of
molecules
per
unit
volume.
If the molecule
of
our
liquid consists of several
atoms,
then
it
shall
be
possible
to
put, in
analogy
with gravitational
forces,
c
=
Eca, where
the
ca's
denote the values
characteristic for the
atoms
of the elements. If
one
also
puts
1/N
=
v,
where
v
denotes the molecular
volume,
one
obtains the final formula