1170 



no longer maintain itself. It is now the qnestion how this has to 

 be expressed in the ?-.i'-figure. 



There exist here two possibilities. It is possible that as fig. 3 

 indicates, the s-.i'-line a b starling from the «-axis, approaches the 

 line p q asymptotically instead of running to the other axis, which 

 means that a mixed crystal of the concentration /; is impossible, as 

 this mixed crystal would require an infinitely large value of ?. 



In the same way the $-.i"-line d c would then approach asymp- 

 totically to r s. 



Then the expression ( ] = M RT loq -~- V- ( (-] dv be- 



comes infinite at a definite value of .r, because then the second 

 term of the second member becomes = oo. 



Another possibility is this, that the ?-,i-line ends suddenly in the 

 figure, as fig. 4 shows. So this figure expresses that the possibility 



Flee. 4. 



of the existence of mixed crystals of the same crystalline form 

 suddeidy ceases at b resp. c, and that the prolongations of the lines 



