144 METALLOIDS. 



334. EXPLANATION. In this experiment 



What takes . , . . . - 



place in the the oxygen in the vial unites with the 



"nenir^' * r n ^ tn6 WirG ' and becomes soli( i, in 



the form of oxide of iron. The oxide 

 fuses into a small globule on the end of the wire, and 

 occasionally falls, and melts its way into the glass. 

 This is apt to be the case, even when water is left in 

 the bottom, so that a vial is likely to be destroyed by 

 this experiment. The process is exactly the reverse of 

 that which takes place when binoxide of manganese is 

 heated, to produce oxygen. In the one case, oxygen 

 was driven from the metal ; in the other, it is drawn 

 to it, though not in the same proportion. 



335. TAPER REKINDLED IN OXYGEN. 



Describe the 



taper experi- Introduce a newly extinguished taper, or 

 shaving, which has a little fire on the wick, 

 into a vial of oxygen. It will be immediately rekin- 

 dled. This experiment may be many times repeated 

 without a new supply of gas. 



336. Combustion is more vivid in 



Explain t/te 



last experi- pure oxygen, than in air, because the latter 

 is diluted with other gases, which do not 

 take part in the combustion. 



337. COMBUSTION OF PHOSPHORUS. 



Describe the . 



experiment Place a piece of phosphorus, of the 



with phosphor gize of a pea? on a piece of chdkj 



slightly hollowed out for the pur- 

 pose, and connected with a cork by a fine 

 wire. Ignite the phosphorus, and introduce 

 it immediately into a bottle of oxygen. It 



