( 1226 ) 
pee een 
by ae 
2 
os : : d*b 
becomes altogether improbable by the consideration of the value of ps 
v 
v d°b 
3. The quantity € rr a). . This quantity is found from the con- 
ie d'p\ . oe 
dition that |— | is =O in the critical point. 
dv? /T 
Equation (II): 
v d°b 
v db\ 2d? 3 
v—b dv) db 2 
do 
0 d°b 2 ) db 
yields for the value of > a if we put ee and (: —5) zE 
2a(f—1) 
— fj? pe 
PLU _ (f—1)(f—4) 
i td at GR 
-(5 TS TE LX) 
For f/=4 we find this value again equal to 0. For f=7 and 
18 
s = 3.78 the value is equal to 0.54 X a nearly 0,2. 
The equation (IX) can be derived from (VI) without it being 
necessary to have recourse to (II). Nor need (VI) be derived from (I). 
bg UL kr 
keeping c, constant as should be done for a constant substance. 
Then we get: 
2 b rs db 
From the relation — =7 —F we could have found En) from v by 
and by differentiation of this equation, keeping c, constant: 
d2b 7 je 
pt tul 5+ )d 
f ett 
CES} 
d d d 
Writing for ee and df for 2 fe), we find: 
T x] & 
or 
