( 158 ) 



1\ = 1200 

 7;= 500 

 Then we get {R = 2) : 



q, = 2400 Gr. cal., 

 q^_ — 2000 „ 



_ 12Q0(l-/? -y-) ^ 500 (1-1,2 /j'(l-.rr) 

 1 + ^ör/ ~ \ J^ lo(j- 



1 — X Z X 



We will begin witli assuming /3' to be veiy lai'ge, e. g. i^' = 5. 

 As we have a' = q^ /?' this means that the latent heat of mixing for 

 the first component when x = 1 (or of the second when .r = 0) 

 is five times as great as the latent heat of solidification of the first 

 component. From the above equation : 



1200(1— 5.t''^) 500(1-6(1— a ')"^) 



Tz=z 



1-x' 1 x' 



1 X 2 X 



we may calculate the temperature T corresponding to an arbitrarily" 

 chosen value of d', the ^•alue of .c' being exceedingly small. So we get 

 for T: 



1200 

 T — 



1-%(1-..)' 



and for .6-' : 



1 x' 25 



^ + l^log-=- -{1- lo,, (1-.)). 



The following table I (p. 151)) gives a survey of the corresponding 

 values of .v, ,v' and T. 



This represents the branch AA' of the meltingpoint-cur\es which 

 starts from 1200° (see fig. 3). AB' is the curve T = f{x). 



If we put 1 — -v = j/ and 1 — ,?■' = ?/' then we have the equations 



^^ 500 (1-6^/'--) ^ 1200 (1-5(1 -yf ) 

 1 1 — v' y' 



Z 1 — 1/ y 



from which ^ve may calculate a ne^v series of corresponding ^'alues 

 of X, x' and 7'. So we get the braiich BE starting from 500° (^.1' is 

 again the curve T=:f{,:o)). The value of // being in this case very 

 small, T may again be calculated from 



and y' from 



500 

 l-0,5%(l-y) 



