385 



telliirinni, tiingsten-l)lue and inai\y other inorganic colloids by fibrons 

 substances '). These [)henonicna have been usually described as 

 adsorptions, although the name adhesion would be the more correct 

 one. If, however there exists a continuity between colloidal and 

 molecular solutions, this will then also exist between adhesion and 

 adsorption. 



Delft, July 1913. 



Chemistry. — '^Equilibria in ternan/ systems'. IX. By Prof. F. 



A. H. SCHREINEMAKERS. 



We will now consider the four-phase equilibrium F -\- F' -\- L -\- G 

 in connection with the saturation- and vapour saturation-curves of 

 F -and of F' under their own vapour pressures. 



These saturation-curves under their own vapour pressures may 

 be situated with respect to one another in diiferent ways : 1. they 

 may intersect one another ; '2. they may touch one another ; 3. the 

 one may be situated outside the other ; 4. the one may surround 

 the other. 



Let us, in the first instance, consider hg. 2, in which the con- 

 tinuously drawn curves i-epresent the saturation curves, the dotted 

 curves the vapour saturation curves of F and of F' under their 

 ow^n vapour pressures. 



At the given temperature, therefore, every liquid of the curve 

 f 'V y g is saturated with the solid F and in equilibrium with a 

 vapour of the corresponding curve f\g^ ; every liquid of the curve 

 fx'y'g is saturated with the solid F' and in. equilibrium with a 

 vapour of the corresponding curve f\gi. 



Because all these liquids are under their own vapour pressures, 

 the pressure changes will, as we have seen before, move along these 

 curves. 



If we now consider ƒ as a point on the saturation curve of F, 

 it is under a pressure F ; if, on the other hand, we consider ƒ as 

 a point on the saturation curve of F' , it is under a pressure P'. 

 The question now arises: Is P the same as P' or are they different ? 



Under the pressure P, therefore, the system F -\- Lf-\- G exists, 

 and under the pressure P' the system F' ~\- Lf-\- G' . At a definite 



1) R. ZsiGMONDY, Verb. d. Ges. D. Naturf. u. Aerzte, 73 Vers. Hamburg 1901, 

 p. 168. L. Vanino, Ber. d. D. Cbem. Ges. 35, 662 (1902). 



W. Spring, Beobacbtungen über die Wascbwirkung von Seifen, Zeitscbr. f. 

 Kolloidcbemie 4, 161 (1909). 



\V. BiLTz. Ber. d. D. Cliem. Ges. 37, 1766 (1904). 



25 



Proceedings Royal Acad. Amsterdam. Vol. XVI. 



