| Arsenic Phosphides, brown substances of indefinite character, were obtained early in the nineteenth century by various methods such as (1) by heating the elements together, (2) allowing phosphorus to stand in solutions of arsenious acid, (3) by the action of phosphine on arsenic halides. The properties of these substances resemble in general those which would be possessed by mixtures—they burn in air giving the mixed oxides, decompose on heating with vaporisation of phosphorus, are oxidised by nitric acid, etc. |