THE TECHNOLOGIST. [Feu. 1, 1865 



330 TIN AND ITS USES. 



are dipped in this, and left to steep for an hour or more, when they are 

 lifted out with tongs, and placed on a block. The plates generally have 

 a surplus quantity of tin adhering to them when taken out of the first 

 pot ; this is removed by dipping them into a pot of molten tallow and 

 brushing. Great care and experience are required in all these manipula- 

 tions in order to cover the plates smoothly, and not have too thick or too 

 thin a coating of tin. More than 55,000 tons of tin plates were exported 

 from Great Britain in 1863. 



The coveting of such an oxidizable metal as iron with tin, like a 

 varnish, is one of the most useful qualities which this metal possesses, 

 and renders it better adapted for making various vessels, such as our 

 common tinware, than any other metal. Nails, bridle bits, and many 

 small articles of iron may be covered with tin by first scouring them 

 to remove the oxide, then dipping them into the molten tin. 



The metal is so ductile, that it can be rolled out into sheets of tin- 

 foil as thin as writing-paper. It is now much used for covering 

 tobacco, for coarse gilding, for what is called " silvering looking-glasses," 

 and for bronzing powders. 



Peroxide of tin is used by jewellers as a polishing material ; and 

 fused with glass it forms a white opaque enamel. It is much used 

 mixed with copper, to form useful alloys of metal, such as gun-metal, 

 the specula for telescopes, the bearings for shafting, the bronze of 

 statues, and was used by the ancients for swords, spears, and armour ; 

 and, it is said, these were tempered by a process now lost to the arts. 



Block tin is struck by dies into various vessels for drinking, such as 

 cups, tea and coffee pots, and mixed with a little copper to give it 

 hardness, it forms the beautiful " Britannia ware." In the chemical 

 arts, tin is dissolved in acids, such as nitric and muriatic, and forms a 

 common mordant for some of the most brilliant colours printed on 

 calicoes, and those dyed on wool and silk. The uses of tin are more 

 various than those of any othej 1 metal, and it possesses very valuable 

 properties. England is the greatest tin-producing country on the globe. 

 She possesses the most abundant natural sources of this metal, and has 

 long been the tin-plate manufacturer of the world. The produce of the 

 metal in Cornwall and Devon is about 11,000 tons per annum, but it is 

 used for 60 many purposes that it is the source of a vast amount of 

 wealth to Great Britain. The whole of the tin trade is in the hands 

 of the Dutch and English, but the latter control the former. 



There is a large quantity of ore which is alloyed in less degree than 

 that to which reference has already been made, but treated in precisely 

 the same manner — this, when smelted, presenting a purer surface, greater 

 fluidity and ductility, is called refined, and is employed exclusively 

 by the makers of tin plate for their manufacture. 



Grain tin ore is always characterised as stream tin, as contra-distin- 

 guished from lode or mine tin ; it is found in deposits or beds in alluvial 

 soil, only a few feet beneath the surface, and it is but fair to conjecture 



