537 



In order to get the solutions of the saturationsnrface D saturated 

 w-ith solid salt, we put together the subslances in such ratios 

 that the solid substance must l)e formed in one case from' 

 Cu SO, . 5H,0 + KCl, in the other from Cu CI,. 2H,0 + K, SO,. In 

 botli instances now D» then Dx was formed. 



In some cases also occurred as solid phase a double salt of the 

 composition : 



2Cu SO,. 3K3 CI,. H,0 = D, 



Later, however, we did not succeed again in getting this salt, hut D^i or 

 Dx appeared instead. The salt Dz Avill therefore, very probably exist 

 in a metastable condition only. 



On account of the uncertainty with respect to the substance D, 

 we will further describe the equilibria as if in the region p q I m ?i 

 occurs only one solid substance D. When in this region more solid 

 phases may occur in stable condition, then the necessary changes in 

 this region will have to be inserted. 



The intersectinglines of the saturationsurfaces represent the quater- 

 nary solutions, which are saturated with two solid substances, con- 

 sequently the quaternary saturationlines. The limit-lines of the 

 saturationsurfaces on the side-planes of the pyramid form the ternary 

 saturationcurves of the four ternary systems, which have already 

 been discussed previously. 



The quaternary saturationcurves are the following : 



gp the saturationline of K, SO, -f- KCl 



iq ,> ,) >i Kj SO, -f Dj.j.^ 



^' ^ >> >) i) CUg -J- Dj.j.g 



b m „ „ ,, Cug -f Ou, 



dn the saturationline of Cu. 



eo ,, ,, 



P q >, „ 



ql >, 



Im „ 



mn „ 



no „ 



p „ 



The first six saturationlines are side-curves; each of these has an 

 end on one of the side-planes of the pyramid. The last six satura- 

 tionlines are middle-curves; each of these has its two ends within 

 the pyramid. 



