158

PROOFS OF THE PROPERTIES OF PHOSPHORUS.

SECT. II.

EXPERIMENTAL PROOFS

OF THE

PROPERTIES OF PHOSPHORUS.

Experiment I.

Phosphorus lurns at the common temperatures of the atmosphere.

LUMINOUS CHARACTERS.

That phosphorus burns at the usual temperature is obviousby writing with a cylinder of it upon black paper, or upon anyother smooth surface. The writing will appear luminous in thedark, as if on fire; the fiery appearance vanishes by blowingon the object, but becomes visible again in a few seconds.

If the writing is performed upon the purple coloured paper ofthis country, the traces will appear red in the day-light after theluminous appearance has ceased.

Rationale. ..The phosphorus has been converted into phos-phoric acid, which changes the blue vegetable colour of the paperto red, the light evinces the combustion of the phosphorus.

Remark. ..It is necessary to place the cylinder of phosphorusin a quill or metallic pencil case, in order that it may be removedfrom die hands, if it should take fire, which may happen, par-ticularly in hot weather; a cup or bason of water should likewisebe near at hand to plunge it into, to prevent accidents.