Thermodynamical Theory of Ternary Mixtures. 945 



o£ the thermodynamical potential, so that provided equations 

 (12) are not verified^ we must have 



<D (2M , 2M 1? p, 0)<<f> (M + 8M , Mx + SM^ M 2 + SM 2 , p, 0) 



+ <S> (M -8M , Mi-SMj, M 2 -SM 2 , p, 6) 



. . . (13) 



From this inequality we can readily deduce the following 

 inequalities : 



BF 



dM 



BF*. 

 BM 2 



>0, 



>o, 



>0, 



and also three inequalities o£ the form 



m*E l _(m\° >0(i * j) 



(14) 

 (15) 

 (16) 



(17) 



Expressing the chemical potentials in terms of the concen- 

 trations s 1 and s 2 , we readily obtain the inequalities 



|fi> 



OSi 



~ds 2 

 B^i^5 2 \'ds 2 ) 



>0 , 

 >0 



(18) 

 (19) 

 (20) 



In my previous work on binary systems I used, as far as 

 possible, special symbols for the differentia] coefficients of 

 the chemical potentials. I shall adopt a similar plan in the 

 present work, using the following special symbols : 



St; ($1, S 2> P,9)= 5—£ (*i, S 2 , p, 6) ' 



OSj 



P, U u s 3 , p, 6) = |L/. ( Sl , S » p, 0) > g= 0. 1. 2) 

 f- (*i, si, p, #)= gg/i (*!, s . 2 ,p, 6) 



