ANTIMONY. 251 



lamp till the coating melts, then suddenly cooled, and 

 afterward cleaned as above directed. The whole sur- 

 face is then found to be covered with beautiful crys- 

 talline forms. 



AOTIMONY. 



Describe the 622. DESCRIPTION. Antimony is a blu- 

 ish white and hi hl y crystalline metal 



what ore is it which does not tarnish in the air. It is 



obtained? 1-11 



so brittle that it may be readily reduced to 

 powder. The ore from which the metal is produced is 

 the grey sulphuret, or antimony glance. 



623. PRODUCTION. Antimony may be 



How is anti- . . 



monypro- obtained from its oxide, by the usual pro- 

 cess of reduction. The sulphuret is first 

 partially converted into oxide by roasting, and still fur- 

 ther by carbonate of soda, which is added in the sub- 

 sequent process. It is then mixed with charcoal, and 

 intensely heated in crucibles. At a white heat the 

 metal fuses, and sinks to the bottom. The soda added 

 in the process exchanges its oxygen for the remaining 

 sulphur of the ore. 



624. ACTION OF HEAT AND AIR. If heated 



How may an- ... , , 4 



timony be before the blow-pipe, antimony soon melts, 

 and burns with a white flame. It is at the 

 same time converted into oxide. A portion of the oxide 

 escapes into the air, while the rest forms 

 a white coating upon the charcoal sup- 

 port. At the high temperature which 

 is here produced, the affinity of the 



