126

PROOFS OF THE PROPERTIES OF IRON.

charcoal powder. A very brittle button will be obtained, whiteon the fracture, and having a striated and granulated appearance:it sometimes crystallizes in rhomboidal prisms. This is phos-phuret of iron.

It may also be formed without the interposition of charcoal,by merely fusing together equal parts of glacial acid of phos-phorus, and iron filings.

Rationale. ..In the first case the charcoal subtracts the oxigenfrom the phosphoric acid, and re-converts it into phosphorus,which, in its nascent state, combines with the iron; in thesecond case part of the iron combines with the oxigen of thephosphoric acid, and becomes vitrified, and the rest forms thephosphuret, which sinks to the bottom of the crucible.

Experiment III.

Iron decomposes sulphuret of antimony.

Bring five parts of iron filings to a red heat in a crucible,and then introduce sixteen parts of powdered sulphuret of anti-mony. Expose the mixture to a sudden and strong heat, andthe iron will attract the sulphur. When the mixture is thoroughlyfused, project, gradually, one part of nitrate of potash in pow-der, which will greatly facilitate the separation of the scoriaefrom tire antimony. The product will be antimony in its metallicstate, which does not contain iron. If, however, one part ofiron be made use of with two of sulphuret of antimony, a littldiron will remain united with it. This was formerly called martialregulus.

Experiment IV,

I

Combination of iron with mercury.

Though iron combines with most metals, its union withmercury could not be effected until lately. Mr. Arthur Aikin