529 
and 
0H 0H  0H/(0z,) el mie ed) OH /òv, 5 
nn mn as) a as) 
Also 
Ovo OV OV: OV, 
neon or DIE 
and 
dH OH, ie 0H, x 0A, 
i), Cate OP aD 
As now for a given phase (h) 
OV; 0A; 
Sete Map Ee 50 
am OE 
since 
OV 02 òH7. OZ). 
a 
oT dT dp dp Opd7 
we have also 
OV a Ona 
a Ope 
If we add (4) and (5) and take (3) into consideration, we have 
as a result: 
OV /dr,\ 0H (dz, = a) 
(sa) tan Ge) + a) ay any yank 
(6) 
dV (du, =) ar (3) 0H (dy, ze) 
— + + — Tg) 
Oy, Ee "dy, \òp dy, \OT dy, \ Op 
From equations (1) we have also 
ENNE 
OES se OTE pei at Tice 
cee een 
ed Oped De. 
Similar expressions may be deduced for the quantities y,, etc 
On substituting these expressions in (6) we obtain: 
= OV\ dx, ee dH) da, 
ae, Salat ti ae oe -)5 ap 
OV OV\dy, (OH AHNdy, 
taranta) ee te =0 
Oy, òv,)òT Oy, Òy,‚/ Op 
: ULE eh ane 
In this equation the expression — — —, (whieh is the same as 
Oz, Oz, 
BY... OF, 
Oz Ox, 
) represents the volume increment associated with the 
3 
