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PROOFS OF THE PROPERTIES OF GOLD.

will be obtained, w hich must be repeatedly washed with distilledwater, and dried on a chalk stone or in a filter. When per-fectly dry it is called fulminating gold, and detonates by heatas may be shown by heating a few grains of it on the point of aknife held over the candle.

Rati on ale... Though the theory of fulminating gold is notyet sufficiently illustrated, it appears highly probable that it is atriple compound; namely, an ammoniacal oxi-muriate of gold.We suppose therefore, that on the application of heat, the mu-riatic acid seizes the oxigen, and reduces the gold to its metallicstate; while the acid itself becomes converted into oxigenatedmuriatic acid. We suppose farther, that after this change theacid detonates with the ammonia; in which case, part of its ox-igen forms water with the hidrogen of the ammonia, .and its ni-trogen is set free. Hence the products of the detonation offulminating gold seem to be metallic gold, nitrogen gas andmuriatic acid and water.

Experiment VII.

Gold is precipitated from its solution ly sulphate of iron.

If we mingle a solution of gold w'ith a diluted solution of greensulphate of iron, a precipitate instantly appears, which is gold inits metallic form, and in a state of absolute purity.

Rationale. ..The green sulphated oxid of iron seizes the ox-igen of the gold, and hence the former re-appears in its metallicstate.

Remark. ..The red sulphate of iron has no effect upon the so-lution of gold; the reason of this may be readily conceived fromwhat has been stated before.