i T 2 Cakes cf Metals. [B ook V t 



fpect nearly allied to the inflammable fubftances. Iron 

 burns with a bright flarne when heated to a certain 

 degree, and immerfed in vital air; and a mixture of 

 tin and nitre produces a violent deflagration. Zincv 

 when heated and acted en only by common atmo- 

 ipheric air, burns with a bright and vivid flame like 

 phofphorus. It is remarkable that mixtures of metals 

 calcine more eafily than the metals in a feparate {late. 

 Thus a mixture of lead and tin, neither of which, 

 when feparate, afford heat and light, in their mixture 

 produce both, and the calcination is remarkably rapid. 

 From the addition of oxygen the weight of the calx 

 is greater than that of the quantity of the metal from 

 which it was produced. In fome metals, however, the 

 attraction for oxygen is fo weak (as is the cafe witli 

 the finer metals) that it is only by particular procefles 

 that they can be combined with it. Metals united 

 with oxygen lofe their fplendor, malleability, and 

 texture, and are denominated calces. 



According to the old chemical theory, the calx of 

 a metal was deemed a fimple fubftancej and was called 

 the earth or ban's of a metal ; and it was fuppofed that 

 this earth, united with phlogiflon, conftituted the 

 metal in its perfect ftate. It is now, however, very 

 fatisfactorily proved, that the metallic ftate is the 

 more fimple, and that the calx is a combination of the 

 metal with oxygen. Metals are reduced from the 

 calciform to the reguline or metallic ftate, by heating 

 them in contact with fubftances which have a ftronger 

 attraction for oxygen than themlelves, as charcoal, tal- 

 low, &rc. 



Metals which are malleable are called entire metals j 

 and thofc Yv'hich are brittle, ferni-metals. Metals arc 

 alib diftinguifhed into perfect and imperfect. The 

 perfect are fuch as are not calcined by being heated in 



contact 



