148 Intelligence and Miscellaneous Articles. 



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ler. The method of preparing aluminum is founded upon the in- 

 oxidability of this metal by water. When an attempt is made to 

 heat chloride of aluminum with potassium in a tube, the action is so 

 strong and the extrication of heat is so considerable, that the appa- 

 ratus is instantly broken. I therefore employed a small platina 

 crucible, the cover of which was kept on by a wire of the same me- 

 tal. At the moment of reduction, the crucible became intensely red- 

 hot, both within and without, although it was but slightly heated ; 

 the metal of the crucible was not sensibly acted upon. The opera- 

 tion may also be effected in a porcelain crucible with a cover at- 

 tached. Some small pieces of potassium of about the size of a pea, 

 and not more than ten at once, are placed in the crucible, and 

 upon them are put an equal number of pieces of chloride of alu- 

 minum of the same size; the crucible is to be heated with the spirit- 

 lamp, at first gently, and afterwards more strongly, and until the 

 spontaneous incandescence of the matter ceases. Excess of potas- 

 sium is to be avoided ; for after it was oxidized, it would dissolve a 

 portion of the aluminum. The reduced mass is generally completely 

 fused, and is of a blackish-gray colour. When all is cold, the cru- 

 cible is to be thrown into a large vessel of water; a gray powder is 

 soon deposited, which, when looked at in the sunshine, appears to be 

 entirely composed of small metallic plates ; the powder is to be 

 washed with cold water and then dried : it is the metal of alumina. 



Aluminum somewhat resembles platina in powder. I discovered 

 some scaly coherent particles, which had the colour and splendour 

 of tin. Under the burnisher it readily assumes the appearance of this 

 metal; rubbed in an agate mortar, it seems to be a little compres- 

 sible, and unites into larger scales, with a metallic lustre ; and it 

 leaves in the mortar traces of a metallic appearance. When heated 

 in the air, until it is ignited, it inflames and burns with great ra- 

 pidity ; the product is the white oxide of aluminum in a hard mass. 

 Reduced to powder and blown upon in the flame of a candle, each 

 particle suddenly becomes an inflamed point, the splendour of which 

 is not less than that of the sparks of iron burning in oxygen gas. 

 In pure oxygen gas aluminum burns with so dazzling a light, that 

 the eyes can scarcely bear it ; the heat generated is so considerable, 

 that the oxide produced is partly fused. The particles which have 

 been fused are yellowish, and as hard as corundum; they do not 

 merely scratch, but they cut glass. In order that aluminum may 

 burn in oxygen gas it must be heated to redness. 



Aluminum is not oxidized by water, and this fluid may sponta- 

 neously evaporate from the metal without its being in the least tar- 

 nished ; when however the water is nearly at its boiling point, the 

 metal is slowly oxidized, and hydrogen is liberated. 



The sulphuric and nitric acids when cold do not act upon alumi- 

 num ; when heated, concentrated sulphuric acid readily dissolves it, 

 and without the evolution of sulphurous acid; the sulphuric solution 

 did not by evaporation give the smallest crystal of alum. 



Aluminum introduced into a solution of caustic potash, even when 

 weak, dissolves readily, and with the evolution of hydrogen; the so- 

 lution 



