700 
identification of the carotinoids of different plants. As Zopr') justly 
says careful macro-chemical investigation alone can lead to decisive 
results in such cases. 
Chemistry. — “Hquilibria in ternary systems [”. By Prof. F. A. H. 
SCHREINEMAKERS. 
(Communicated in the meeting of October 26, 19.2). 
On the equilibria oecurring in ternary systems between liquid and 
vapour different theoretical *) and experimental*) investigations have 
already appeared previously. We will now aiscuss a few cases where, 
in addition to liquid and vapour, solid substances occur also. 
The syster F L G. 
We choose for fa ternary compound and will assume that the 
three components occur in the vapour. 
We now choose at a definite constant temperature T such a 
pressure P that no vapour can form. The isotherm can then consist 
only of the saturation line of the solid substance F. This saturation 
line is a closed curve surrounding the point F like the closed curve 
of Fig. 1, for instance. 
On reduction of P a gas region appears somewhere and at the same 
time a heterogeneous region separating the gas region from the liquid 
region. In Fig. 1 the gas region is indicated by G, the liquid-region 
by L: the drawn line is the liquid-line, the dotted one the gas- or 
vapour line of the heterogeneous region. The straight lines drawn 
in this heterogeneous region unite the liquids with the vapours with 
which they can be in equilibrium. 
We now have in Fig. 1 two homogeneous regions, namely the 
liquid region L and the gas region G; in addition we find two 
heterogeneous regions. : 
In one of them a mixture dissociates into L+ G; we will call 
a) W. Zoer, Zar Kenntnis der Färbungsursachen niederer Organismen (Dritte 
Mitteilung), Beiträge zur Physiol. u. Morph. niederer Organismen, 1892, Erstes 
Heft, p. 36. 
*) J. D. vAN DER WaALS. These Proc. Vol. JV p. 448, 539, 681; Vol. V p.1, 
121, 225. (1902). 
F. A. H. SCHREINEMAKERS. Zeitschr. f. phys. Chem. 36 257, 413, 710 (1901) 37 
129 (1901) 38 227 (1901) 43 671 (1903) 
B. M. van DALFSEN. Dissertation, Amsterdam. (1906). 
8) F. A. H. ScHREINEMAKERS. Zeitschr. f. Phys. Chem. 39 485, 40. 440, 41. 
331 (1902), 47 445, 48 257 (1904). 
B. M. vAN DALFSEN. l.c. 
