ANTIMONY. 



SECTION VI. 



ORDER III. METALS WHOSE OXIDES FORM WEAK BASES, OR ACIDS, 



This order includes Tin, Antimony, Arsenic, Chromium, Vana- 

 dium, Tungsten, Molybdenum, Columbium, Titanium. Tellurium, 

 and Osmium, 



TIN. 



Is found in nature as an oxide, from which it may be procured by 

 heating with charcoal. The varieties known in commerce are block 

 and grain tin. 



Prop. — Has a white colour, silvery lustre, is very slowly tar- 

 nished by exposure to the air ; very malleable, quite ductile, soft, 

 and inelastic, and produces a crackling noise, when bent backwards 

 and forwards ; sp. gr. about 7 ; fuses at 442°; heated to whiteness, it 

 burns, and is converted into the peroxide. Symb. (Stanum) Sn. — Eq, 

 58. It forms three oxides. 



Protoxide, SnO;— formed by adding an alkaline carbonate to a 

 solution of the protochloride ; a white hydrated protoxide falls. 



Sesquioxide, SnPg,— has a grayish colour. 



Peroxide, SnO^ ;— prepared either by precipitating by an alkali 

 from a solution of the perchloride, or by the action of nitric acid on 

 metallic tin. Very strong nitric acid has no effect on tin ; but, if 

 diluted, violent effervescence ensues from the escape of nitrous acid 

 and binoxide of nitrogen, and the hydrated peroxide is produced ; 

 ammonia is also generated at the same time, the hydrogen being 

 furnished by the water. 



Protochl&ride, SnCl,— made by dissolving tin in hot hydrochloric 

 acid ; occurs in crystals. It is much used as a deoxidizing agent. 



Perchloride, SnCl^, called ihefvmirtg liqiwr of Lihavius ;—m^Ae 

 by heating the protochloride, or metallic tin, in chlorine ; it is a very 

 volatile, colourless liquid, emitting dense white fumes on being exposed 

 to the air ; it is used as a mordant in dyeing. 



There are three sulphurets of tin— the protosulphuret, sesqvisul- 

 2)hiiret,m'idihi-sulphnret; the latter is sometimes ie^meA mosaic gold. 



Tesi.— Solution of chloride of gold throws down, with the proto- 

 chloride of tin, the purple of Cassius. 



ANTIMONY, 



Occurs in nature generally as a sidphuret, which, in commerce, is 

 called crude ayitimony, while the pure -metal is named regulus of 

 antimony. It may be obtained from the sulphuret by heating it 

 with iron filings. 



Projj. — A bluish-white colour— crystalline structure — brittle— sp. 



