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PROOFS OF THE PROPERTIES OP COPPER

Experiment IV.

Copper combines with sulphur loth in the wet and in the dry way,(Preparation of sulphuret of copper.)

Take equal quantities of copper filings and sulphur, and hav-ing formed them into a soft paste, by the addition of a sufficientquantity of water, expose the mixture to the air; lixiviate it atthe end of some days, and sulphate of copper will be obtainedby crystallizing the lixivium. ,

A sulphuret of copper may be obtained by putting into acrucible alternate strata of thin plates of copper and sulphur inpowder. The crucible is then to be exposed to a gradual heat,in a furnace, till no more vapours issue from it. Keep the cru-cible in a dull red heat for an hour, and then sqffer it to cool.The product will be a sort of copper slag, brittle, and of aniron colour, which when worked exhibits the colour of greenoxid of copper.

Experiment V.

Copper unites readily until zinc, andforms a compound ,called brass.

Brass is produced by the following processes: Put into a cru-cible four parts of granulated copper and twelve of zinc, andnearly fill the crucible with charcoal-powder, cover it and bringit briskly to a red heat, the copper will unite with the zinc andform brass.

If plates of copper be cemented with native oxid of zinc re-duced to powder, and mixt with charcoal also in powder, bybringing the mixture to a red heat in a covered crucible, thecopper and zinc will unite and likewise form brass.

Brass is made in the large way by a process similar to this.