Tungsto-arsenites

By treating solutions of tungstates with arsenious acid the following crystalline compounds have been obtained by Gibbs,

7(NH₄)₂O.2As₂O₃.18WO₃.18H₂O,
4BaO.As₂O₃.9WO₃.21H₂O,
9Na₂O.8As₂O₃.16WO₃.55H₂O.

This author also describes compounds of composition 10K₂O.As₂O₃.4AS₂O₅.21WO₃.26H₂O,
10K₂O.14AS₂O₃.3P₂O₅.32WO₃.28H₂O,
5K₂O.Na₂O.2As₂O₃.2P₂O₅.12WO₃.15H₂O, and
7K₂O.AS₂O₃.4P₂O₅.60WO₃.55H₂O.