1 1 . Silver is of specific gravity 1 0400, it burns 

 more readily than plantinum or gold, which require 

 the intense heat of electricity. It readily unites to 

 sulphur.. The number representing it is 205. 



12. Mercury is the only known metal fluid at 

 the common temperature of the atmosphere ; it boils 

 at 66 , and freezes at 39 below 0. Its specific gra- 

 vity is 1356 . The number representing it is 380. 



13. Copper is of specific gravity 8890. It burns 

 when strongly heated with red flame tinged with 

 green. The number representing it is 1 20. 



14. Cobalt is of specific gravity 7^00. Its point 

 of fusion is very high, nearly equal to that of iron. 

 In its calcined or oxidated state, it is employed for 

 giving a blue colour to glass. 



15. Nickel is of a white colour : its specific gra- 

 vity is 8820. This metal and cobalt agree with iron, in 

 feeing attractible by the magnet. The number repre- 

 senting nickel is 111. 



16. Iron is of specific gravity 7700. Its other 

 properties are well known. The number represent- 

 ing it is 103. 



17. Tin is of specific gravity 7291 ; it is a very 

 fusible metal, and burns when ignited in the air : the 

 number representing the proportion in which it com- 

 bines is 110. 



1 8. Zinc is one of the most combustible of the 

 common metals. Its specific gravity is about 7210. 

 It is brittle metal under common circumstances ; but 

 when heated -may be hammered or rolled into thin 

 leaves, and after this operation is malleable. The num- 

 ber representing it is 66. 



