( 619 j 
de the saturation line of the (NH,), SO, 
CO at 5 Beba oe OR SOL ANE BREE EE 
OB i; é Paki CU DO EE 0 
If we unite the point O with the point representing the double 
salt CuSO, . (NH,),5O,.6H,O we intersect the saturation line of double 
salt the latter being, therefore, soluble in water without decomposition. 
2. The system: water, CuSO,, Cu Cl,. 
Only two solid substances namely CuSO,.5H,O and CuCl, .2H,O 
occur in this system as solid phases by the side of liquid; point % is 
the solution saturated with both salts, 4z is the saturation line of the 
CuCl, .2 H,O, ka that of the CuSO, .5 H‚O. 
3. The system: water, CuCl,, NH,Cl. 
The isotherm of 30° has already been determined by Dr. P. MeerBure. 
As solid substances occur, by the side of liquid, CuCl, . 2 H,O, NH,Cl 
and CuCl, ,2NH,Cl.2H,O. The saturation line of the CuCl,.2H,O 
is represented by zh, that of the CuCl, .2NH,Cl.2H,O by hy, and 
that of the NH,Cl by fg. The line uniting point O with the point 
representing the double salt intersects the saturation line of the double 
salt the latter being, therefore, soluble in water without decomposition. 
4. The system: water, (NH,),SO,, NH,Cl. 
In this system only (NH,,5O, and NH,Cl occur as solid substances; 
the saturation line of the first salt is represented by de, that of the 
second by ef; e represents the solution s&turated with both salts. 
After this short review of the four ternary systems we can now 
discuss the quaternary system. 
At 30° the following substances can occur as solid phases in 
coexistence with liquid: 
CuSO, .5 H,O, CuCl, . 2 H,0, (NH,),SO, NH,Cl, CuSO, . (NH,),SO,.6H,O 
and CuCl, . 2 NH,CI. 2 H,O. 
As the solutions, which in a quaternary system are saturated with 
solid matter are represented by a surface, there must be six saturation 
surfaces; their projections are indicated in the figure, namely : 
abmlk is the saturation plane of the CuSO, . 5H,O 
Dn ve ne ets ONO. AHO 
GONE 55 ss 9 Bits pels, HCl 
BEDE na nn 03 » 9» 9» (NH,),SO, 
hlmog ,, » is Paes, UC ANH Ol) DEED 
bmope ,, 5; re on wh, CuSO, ONE 0H-O 
