460 Sir Henry Boscoe [May 3, 



For the production of 22,400 lbs. double cliloride is required : — 



Common salt 8,000 lbs. 



Alumina hydrate 11,000 „ 



Chlorine gas 15,000 „ 



Coal 180 Urns. 



For the production of 15,000 lbs. of chlorine gas is re(][uired: — 



Hydrochloric aoid 180,000 lbs. 



Limestone dust 45,000 „ 



Lhne 30,000 „ 



Loss of manganese .. 1,000 „ 



(These figures were rendered more evident by the aid of small 

 blocks, each cut a given size so as to represent the relative weights of 

 the different materials used to produce one unit of aluminium.) 



It might seem, on looking over the above numbers, as if an 

 extraordinary amount of waste occurred, and as if the production is 

 far below that which ought to be obtained, but a study of the figures 

 will show that this is not the case. I would wish to call attention to 

 one item in particular, viz. fuel, it having been remarked that tl'e 

 consumption of coal must prevent cheap production. I think when it 

 is remembered that coal, such as used at the works, cost only 4s. per 

 ton, while the product is worth 2210/. per tou, the cost of coal is 

 not an item of consequence in the cost of production. The total cost 

 of tlie coal to produce one ton of metal being 50Z. ; the actual cost 

 for fuel is less than sixpence for every pound of aluminium produced. 

 The ratio of cost of fuel to value of product is indeed less than is the 

 case in making either iron or steel. In concluding my remarks as to 

 the method of manufacture and tlie process in general, I may add 

 that I do not think it is too much to expect, in view of the rapid 

 strides already made, that in the future, further improvements and 

 modifications will enable aluminium to be produced and sold even 

 at a lower price than appears at present possible. 



Properties of Aluminium. 



In its physical properties aluminium widely differs from all the 

 other metals. Its colour is a beautiful white, with a slight blue tint. 

 The intensity of this colour becomes more apparent when the metal 

 has been worked, or when it contains silicon or iron. The surface 

 may be made to take a very high polish, when the blue tint of the 

 metal become manifest, or it may be treated with caustic soda and 

 then nitric acid, which will leave the metal quite white. The 

 extensibility or malleability of aluminium is very high, ranking with 

 gold and silver if the metal be of good quality. It may be beaten 

 out into thin leaf quite as easily as either gold or silver, although it 

 requires more careful annealing. 



It is extremely ductile and may be easily drawn, especial care 

 only being required in the annealing. 



