173 
HgCl,; the point of intersection c of the two saturation lines repre- 
sents the solution saturated with CuCl, .2H,O + HgCl,. 
The solubility curve be of the HgCl, has a peculiar form; for a 
tangent may be drawn to it parallel to the side W.CuCl,. This 
means, in our case, that the solubility of HgCl, first increases and 
then decreases with an increased CuCl,-content of the solution. From 
the Fig. 1 it is shown that the solubility of HeCl, is much increased 
by addition of CuCl,; from the table we see that the solubility of 
HgCl,, which in pure water amounts to 8.51 °/, can? increase to 
fully 52°/, by addition of CuCl.,. 
The isotherm represented schematically in fig. 1 can be drawn 
with the aid of the determinations communicated in the table. As 
not only the compositions of the liquids, but also those of the corre- 
sponding “residues” have been determined, the composition of the 
solid substance may be deduced therefrom. We find that the solu- 
tions of branch ac are saturated with CuCl,.2H,O and those of 
be with HeCl,. 
Compositions in 9%) by weight at 35°, 
of the solution of the residue 
: SS solid phase 
*/o CuCly | /) Hg Cl, | 0/, CuCl, | % Hg Cl 
if 
44.47 0 = = CuCl, . 2H,O 
Bea 21.08 |" 51.0 13.04 
26.07 | 31.3 | 55.82 | 16.97 
28.8 | 44,47 BET 10:10 
„ 
21.49 | 50.45 | 43.60 | 36.63 |CuCl,.2H,O + HeCl, 
21.47 | 50.60 | 15.08 | 74.35 i ae 
21.54 | 50.37 = = 5 aes 
19.40 | 52.44 3.0 91.94 HgCl, 
18.48 | 52.54 4.6 87.57 ‘ 
18.06 | 52.81 3.17 | 90.06 A 
4 7S th SILOS En ee P 
5.94 | 49.5 ee a2 8 
2.64 | 23.87 = 5 
0 8.51 — — 
