DOC.
35
203
(1)
u
"
y
P +
II
dN
Dy
dM
Tz
'
u
»
fP
1
dY
+ Vlt
=
dL
Tz
'
dN
Dx
'
u
«
yP
,
1
dZ
+ Vit
=
dM
Dx
dL
Dy
'
1
dL
Vit
~
dY
Tz
'
dZ
Dy
'
1 dM
Vit
~
dZ
Dx
dx
Tz
'
1
dN
7
It
~
dX
Dy
'
dY
Dx
[3]
hold
in
the entire
space,
where
A
dX
A
dY
A
dZ
P
-Tx +
Tv* Tz
denotes
the 4t-fold
density of
electricity.
If
one
adds
up
equations
(1)
after
they
have been successively
multiplied
by
it
Xx'
h
Yx
• *
ir
Nx
and integrates them
over
the
entire
space,
one
obtains, after
a
few
integrations
by
parts, the
following
equation
(2)
*
|
£
x(uX+ vY
+
wZ)dr
+ x-
J2
...
+
Nt)dr
V
5?
(YN-ZM)dr
=
0.
[4]
The
first
term
of
this
equation represents the
energy
supplied
by
the
electro-
magnetic
field
to
the bodies
m1...mn.
According
to
our
hypothesis
on
the
dependence
of the
masses on energy,
the first
term
of the
sum
should therefore
be
equated
with the
expression
[5]
nl'v dm
v
Jt