558 
minimum melting point in which points 
the lines for the quasi-unary two-phase 
equilibrium compound + Z and com- 
pound + G meet the three-phase line, 
respectively. 
The connexion between this graph- 
ie representation of the three-phase 
equilibrium and the analytical ex- 
pression used in § 2 has been work- 
ed out in the papers cited. On CPF 
the concentration fraction dn 
LCS —&L 
grows steadily greater (compare the 
Tr-projection). The value for the maximum 7’ is soon attained, then 
the numerator of equation 2 becomes negative. Just before vs becomes 
= er (comp. equation 1) 
(Sr) VGS will become —=(@s—rG) VLS 
dP awe Aut 
and, therefore — = (point £) for the concentration fraction ap- 
a 
roaches co (when ws == a,) and so a value of about 10“ is once attained. 
| 
The numerator then has a great negative value, the denominator 
o o 
: LP Phe 5 
starts from Jè, also negative; hence i positive. In Fay = ag; 
C 
the concentration fraction in equation (2) which before # is very 
largely positive, becomes very largely negative beyond /. This 
negative value declines until in G it has become 0, as in that point 
rg=es. The concentration fraction now again assumes a rising 
positive value and in H it becomes 1 as in that point rg = «7 and 
it will thus soon again attain a value causing 
as—eg  Qa@s 
= (3) 
str Qrs 
we then are in the minimum 7; For if now we examine the Tx 
figure between A and d we readily notice that after the crossing 
of tbe G- and Z-branch in h #s— eG increases much quicker in 
(negative) value than ws— 7; hence, the concentration fraction thus 
continues to rise at first, but in dd’, ey and xg do not usually differ 
much *) as both are situated very close to the b-axis. Consequently 
the value of the concentration fraction has again begun to fall and 
once again the relation (3) has been satisfied, so causing the maxi- 
mum 7’ to appear. For the appearance of the minimum 7’, and the 
1) Much less than drawn in lig. 2. 
