1136 

 Chemistry. — "Equi/ihria in ternary systems. XIV. By Prof. 



SCHREINEMAKERS. 



(Communicated in the meeting of March 28, 1914). 



After the previous discussion of the saturationcurves under their 

 own vapourpressure and of the boiliug|)oiMtcurves of a component, 

 we must yet deduce its solutionpatlis under its owu vapour-pressure. 

 As, however, we discussed already formerly those of binary and 

 ternary compounds the reader may easily deduce those of a component. 



In the i)revious communications Vll — X we have discussed the 

 fourphase-equilibrium F -{- F' -\- L ^ G ; for this we have assumed 

 that F and F' are both ternary compounds. It is, however, easily 

 seen that these considerations apply also to binary and unary sub- 

 stances, provided that F and F' contain together the three com- 

 ponents ; the line J^ F' is then situated, perhaps its extremities 

 excepted, completely witliin the componentstriangle. Then the 

 licpiid contains aiso the three components, so that the quantity of 

 none of them can approach to zero in il. When /'' and F' contain 

 together o\\\y two components, the line FF' coincides with one of 

 the sides of the componentstriangle. The quantity of one of the 

 components may then approach to zero in the liquid and in the 

 vapour, so that we must contemplate this case separately. 



When we take e. g. the ternary equilibrium i> -j- C -\- L -\- G, it is 

 evident that the quantity of A can become equal to zero in the 

 li(piid and in the vapour. If the liquid and the vapour, in which 

 the quantity of one of the components becomes equal to zero, is 

 represented by L^ and G„, then the binary equilibrium B-\-C-\-L^-]rG„ 

 arises. Herein L^ is the eutectical liquid under its own vapour- 

 pressure of the binary system B -f C; G^ is the coi-responding 

 vapour; the corresponding temperature and pressure we call 7'„ and 

 P„. The ternary equilibrium B -\- C -\- L -[- G terminates, therefore, 

 when the quantity of .4 becomes zero, at the temperature 1\ and 

 under the pressure P^ in the binary eutectical point with the phases 

 B-^C-\-L,^G,. 



Reversally we may also say that by addition of A the fourphase- 

 equilibrium B -\- C -\- L -\- G proceeds from the binary eutectical 

 point with the phases B -{- C -\- L ^ -\- Gf,. 



When we take a eutectical point B -{- C -\- L^, under a constant 

 pressure, so that no vapour occurs, the threephaseequilibrium 

 y>_|_(;_j_/^ is formed on addition of A and the eutectical tempe- 

 rature is always lowered. From this naturally the question follows : 



