( 620 ) 
In order to facilitate the survey, I have indicated on each of the 
saturation surfaces the solid substances with which the solutions are 
saturated; for the sake of brevity Cu, stands for CuCl, . 2H,O. 
The lines in which the surfaces intersect each other two by two 
represent the solutions saturated with two solid substances. They are 
the following: 
ep, the saturation line of (NH,),SO, + NH,Cl 
Cp: mee ‘3 poy (NEY) SO, 4 CuSO,” NH SO Gag 
bies En » » CuSO,.5H,O + CuSO,.(NH),S0,.6H,0 
PAAL 4 » » ©usO,.5H,O + CuCl, . 2H,0 
ia <i > » CuCl, .2H,O + CuCl, .2NH,Cl. 20,0 
OG, os és. » » NH,Cl+ CuCl, . 2NH,Cl.2H,O 
mo, 5; 5 2; CusO,,(NH)S80, 16HO + 
+ CuCl, . 2NH,Cl . 2H,O 
Dld J >» CusO, .(NH,),SO, .6H,O + NH,CI 
Mis, * 3° ay, OO, SH, OS Cull. INHSCI ZRD 
The points in which the saturation lines meet three by three are 
the saturation points; they represent the solutions saturated with 
three solid substances. We have; 
p, saturated with CuSO, . (NH,),SO, . 6H,O + (NH),50, + NH,Cl 
0, ys » CusO,.(NH,),SO,.6H,0 + CuCl, .2NH,Cl.2H,0 + 
B + NH,Cl 
m, 44 , CuSO,.(NH,),SO,.6H,O + CuCl, .2NH,Cl.2H,0 + 
+ CuSO, .5H,0 
l, zh » CuCl, .2NH,Cl.2H,0 + CuSO, .5H,0 + 
+ CuCl, . 2H,0 
We can now see plainly from the figure the solid substances by the 
side of which a defined solid substance can exist in saturated solution. 
We notice that CuSO,.(NH,),5O,.6H,O can exist in coexistence 
with (NH, ,SO,, NH,Cl, CuSO, .5H,O and CuCl, . 2NH,CI. 2H,0 but 
not together with CuCl, .2H,O; CusO, . 5H,O can exist by the side of 
CuCl, .2H,O, CuCl,.2NH,Cl.2H,0 and CuSO, .(NH,),SO,. 6850 
but not together with (NH,),SO, or NH,CI. It further appears that 
both double salts behave in regard to each other and to water as 
single substances; at 30° we may have a series of solutions 
saturated with CuSO, .(NH,),SO,.6H,O, a series saturated with 
CuCl, .2NH,Cl.2H,O and one solution saturated with both at the 
same time; the latter is represented by point n. 
Many other conclusions may be drawn from the figure, but this I 
must leave to the reader. 
