Chemistry. — "In-, mono- and divariant equilibrin" . XXIV. By 



Prof. F. A. H. SCHREINKMAKERS. 



(Communicated at the meeting of October 27, 1923). 

 Components and composants. 



Ill our considerations we have lepiesenled the composition, the 

 thermodynainical potential etc. of tlie different piiases with the aid 

 of the qiianlities of the components ; we may, however, also represent 

 them in anotlier way. 



For example we take a quaternary system with the components 

 X Y Z and U. The composition of an arbitrary phase may he 

 represented by : 



F = xX + yY+zZ-\r(\-x~-y — z)U . . . (1) 

 wherein .cX, >/ V etc. represent x quantities of X, y quantities of 

 Y, etc. In a system of coordinates with the axes .(■ y z the com- 

 ponent V is situated, therefore, in tlie origin of the coordinates; we 

 call U the fundamental-component. 



We now take in the quaternary system under consideration, four 

 arbitrary phases M N P and Q; we may represent the composition 

 of the phase i^ by : 



F=zml/+ nA^ + pP-f (1 — m — n — p) Q . . . (2) 



As definite values of m n and p belong to each composition of 

 F, we may, therefore, also consider the composition of i^ as a function 

 of in n and j). 



We call the phases M, iV, P and Q, in which we express the 

 composition of a phase F, the com])Osants of the system; we shall 

 call Q the fundamental composant. 



When we represent the composition of a phase F by (1), con- 

 sequently expressed in its components, then its theiniodynaniical 

 potential, its free energy etc. a function of x y and z; when we 

 represent the composition by (2), consequently expressed in composants, 

 then we may represent its thermodynamical potential, its free energy 

 etc. also as functions of m. n and /;. Of course there exist relations 

 between those two way of representations; we shall deduce I hem 

 further. 



We now consider the equilibrium between a variable (f.i. liquid) 



