Scheerer on Isomorphism. 195 
nesia 3°86, water 46°83 = 99°65. This gives an oxygen ratio of 
17°39 S : 5:74Co and Mg : 13-88 x, which is convertible to 
17-398 : 17-66 (R) : 5°88 x4) in which case it corresponds very 
closely to the formula, (Co) S+ 4H, which requires an oxygen 
ratio of 17-64: 17-64: 5:88. The formula of the artificial sul- 
phate of nickel, NiS+7H, may be converted in like manner to 
(Ni)? S+aH. 
Kopp has examined a sulphate of cobalt from Bieber, the com- 
position of which differed from that analyzed by Winkelblech. 
It is composed of sulphuric acid 19-74, protoxyd of cobalt 38-71, 
water 41-55 = 100-00, corresponding to the oxygen ratio, 11-828 : 
8:25 Co : 12:31 x, which is convertible to— 
11:82 : 12-00Co : 25-68 = wef 
12-00 : 12-00 — ; 24-00 She 
It would be interesting to ascertain whether this bieberite has the 
same form of crystal as that examined by Winkelblech, which 
without a doubt is to be looked upon as the normal salt. 
5. Vitriol. (Haidinger.) 
The formula of sulphate of copper is CuS+5H. Assuming 
that 1Cu may be replaced by 23, this formula is equivalent to 
(Cu)? S+H. Sulphate of copper by this means receives a for- 
mula similar to that of the other sulphates here mentioned, (with 
the exception perhaps of melanterite,) and this harmony appears 
to me to bear out the truth of the assumption I have adopted, 
and this opinion is still farther supported by the formula obtained 
by calculation for the phosphates and for the arseniates of copper. 
6. Basic Sulphate of Copper. 
The oxygen ratio of this mineral, resulting from Berthier’s analy- 
sis, is 9-93 S : 13°35Cu : 15-29 w, or otherwise by conversion, 
9-938 : 19:33 (Cu) : 3:33 
975 3 19°50 : 3°25 
7. Sulphate of Alumina. 
The formula of sulphate of alumina, both that which occurs 
native and the artificial, is Al $2418 H, which expression may 
be thus written, 2(R)s S+AlS. Inthe artificially prepared pure 
salt, (R) consists entirely of water, whereas in the natural salt, it 
(Cu) S 4m 
2 ae Lr cee 
Riad han MMM aE aN Mili re beeen” -/ ST ih" Ta Sahl OO “2 . i ulin as Ciglat 
