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PROOFS OF THE PROPERTIES OF OXIGEN GAS.

fixed. The thread or wood is then lighted and the wire quicklyintroduced into the receiver; an intense deflagration of the wireimmediately takes place, throwing out a number of brilliantsparks, ascending in a spiral direction with a beautiful sun-likebody, giving in a darkened room a luminous appearance incon-ceivably striking.

If we examine the weight of the iron after combustion wefind it augmented in proportion to the quantity of oxigen it hasabsorbed. It has at the same time lost its metallic splendor, andobtained properties different from those it possessed before.

The use of the heat employed for the first ignition is to se-parate the particles of the metal from each other, and to dimi-nish the attraction of cohesion or aggregation.

Rationale. ..The iron whjin heated to a certain degree decom-poses the oxigen gas; the equilibrium of the attraction subsistingbetween the caloric and solid oxigen being interrupted, it isacted upon by two separate and opposite forces, that of the at-traction for caloric to remain in the gazeous state, and that ex-erted by the metal; the latter power being greater, it unites withit and gives out at the same time its caloric and light. The newsubstance produced, consisting of oxigen and iron, is called oxidof iron. It is not an acid, but it is changed to an intermediatesubstance, approaching to the acid state, though not possessingall the requisite properties.

Experiment II.

Combustion of zinc in oxigen gns.

Take some turnings of zinc, form a ball of them, and affix itto a copper wire; insert a small bit of phosphorus into the ball,set fire to it, and introduce it quickly into a bottle filled withoxigen gas ; the zinc will thus take fire, and burn with a beau-tiful green flame surrounded by a white one.