MERCURY. 259 



superior affinities of zinc for acetic acid. The zinc 

 takes away acid and oxygen from successive portions 

 of the sugar of lead, and leaves the particles of lead 

 subject to the laws of crystallization. At the same 

 time, the zinc having acquired possession of the acid 

 and oxygen, comes into solution as acetate of zinc. A 

 similar arborescence is produced in a solution of silver 

 by metallic mercury. 



How are shot ^47. MANUFACTURE OF SHOT. Shot are 



made? prepared by pouring melted lead through 



perforated iron vessels. The drops are made to fall 

 from a great height that they may become cooled and 

 solidified in their descent. They are caught in water 

 that their shape may not be impaired. Having been 

 assorted by means of seives, they are" polished in 

 revolving casks, containing a small portion of black lead 

 or plumbago. 



Mention other ^48. OTHER USES OF LEAD. In the 



uses of lead. form of sheet lead this metal is applied 

 to a variety of familiar uses. It is also largely em- 

 ployed in the manufacture of lead tubing. It is a 

 constituent of various alloys, among which pewter 

 and type metal are the more important. 



CLASS VI. 



MERCURY. 

 649. DESCRIPTION. Mercury is a white 



Mercury de- - . , i / i i i 



scription, sol- fluid metal of high lustre and beauty. It 



"discover? retains the fluid condition at all ordinary 



temperatures,and is only rendered solid by 



