Fossils* 173 



which is one of its characteristic proper-* 

 toes. The specific gravity of tin is varia- 

 ble from 7,216 to 7,331. Its gravity de- 

 creases in the ratio of its purity. 



Zinc is a white metal, of a radiated 

 texture, changing into the foliated* It is 

 of a middle kind betwen the malleable 

 and brittle metals, and may be extended 

 into thin laminae, at least between metal- 

 lic cylinders in rolling mills. The spe- 

 cific gravity of this metal is from 6,862 



Antimony has a white colour, resem- 

 bling that of tin, a foliated radiated text- 

 ure, and is very brittle. Its specific gra- 

 vity varies from 6,702 to 6,860. In the 

 air it loses little of its metallic splendour 

 and it does hot rust in the strict sense of 

 the word. 



Manganese is a white, hard, brittle me- 

 tal, whose specific gravity is found to be 

 from 6,850 to 7,OOO. 



Molybdena has a pale lead-grey colour, 

 a metallic lustre, and a laraellated fracture 

 it is very soft, and marks paper easily, 

 leaving a shining trace. Its specific gra- 

 vity is between 4,138 and 4,569. 



Wolfram is a metallic substance of modr 

 P 



