DO CHEMISTRY. 



sp. gr. 8*7 ; melts below 500° ; when strongly heated, it burns, forni- 

 ing the oxide. 



BISMUTH. 



Occurs both native, and in combination ; may be procured pure 

 by heating the subnitrate with charcoal. 



Prop. — A crystalline metal, of a reddish-white colour and me- 

 tallic lustre ; when slowly cooled, it yields cubical crystals ; fuses at 

 476°, and in close vessels sublimes unchanged ; in the open air 

 burns with a bluish flame, and is converted into the oxide; its pro- 

 per solvent is nitric aid. It forms two oxides. Sp. gr. 10. — -Eq. 71. 



Protoxide, BiO ; — the basis of all the salts, has a yellow colour ; 

 obtained by heating the subnitrate. 



Peroxide Bi^Og. — Bismuth unites also with chlorine and sulphur. 



Nitrate of Bismuth ; — made by dissolving the metal in nitric acid, 

 and evaporating. This, when thrown into water, is decomposed into 

 the soluble supernitrate, and the insoluble subnitrate, which subsides 

 as a white powder. 



The best test is the formation of the subnitrate. 



MANGANESE. 



Is found in nature as an oxide; procured from this by intensely 

 heating with charcoal. 



Prop. — A hard, brittle metal, of a grayish-white colour, very in- 

 fusible, sp. gr. ; about 8 ; forms seven compounds with oxygen, viz. : 

 Protoxide, MnO, Sesquioxide, Mn^Og, Peroxide, MnO^, Red oxide, 

 MUgO^, Varvicite, Mn^Oy, Manganic acid, MnOg, Permanganic acid, 

 MugOy. The most important of these, to the chemist, is the peroxide, 

 or black oxide, which occurs abundantly in nature. It is used in 

 the arts, in the manufacture of glass ; and by the chemist for pro- 

 curing chlorine, bromine, and oxygen. 



NICKEL AND COBALT. 



These two metals strongly resemble each other : both occur in 

 combination with arsenic. Nickel is found associated with meteoric 

 iron, and is strongly magnetic. Cobalt is not so. Both have a 

 white colour. Nickel is malleable ; Cobalt is brittle. Nickel is em- 

 ployed in the arts, in the preparation of German silver — an alloy of 

 copper, zinc, and nickel. 



The best test to distinguish cobalt from nickel, is the fine blue 

 colour communicated by the former to the flame of the blowpipe, 

 when fused with borax. 



URANIUM, CERIUM, AND LANTANUM. 



These are very rare metals, and of no practical use. The latter, 

 Lantanum, was very recently discovered by Mosander. 



