228 METALLOIDS. 



of which a piece of a second stem is fitted, 



as represented in the figure, may be made 



to answer the purpose. With its aid, a 



lamp or candle flame is converted into a 



miniature blast furnace. The mouth is ap- 



plied at the end of the long stem, while 



the shorter one carries the blast to the flame. The 



orifice of the latter should be extremely small. It 



may be so rendered, by filling with clay, and then 



piercing it with a needle. 



566. OXIDIZING BLOW-PIPE FLAME. To 

 d oxidize with the blow-pipe, the flame, 



for oxidation? mixed with a large proportion of oxygen, 



Give an ex- . _ . . .. 



ample. is blown forward upon the metal, or other 



material, subjected to experiment. This is 

 effected by introducing the extremityof the blow-pipe, 

 a little within the flame. 

 The air of the lungs be- 

 comes thus mixed with 

 the rising gases. The 

 result is, a slender, blue 

 flame, at the point of 



which, within its fainter blue envelop, the metal is 

 to be held. A piece of lead, of the size of a grain of 

 wheat, placed on charcoal, hollowed out for the purpose, 

 and exposed to the flame, will soon bo converted into 

 litharge. The oxide will be recognized by the yellow 

 incrustation which it forms upon the charcoal support 

 567. REDUCING BLOW-PIPE FLAME. To 



How is the 



blow-pipe used convert oxides into metals, or in other 



blow-pipe, the gases of the flames are 



