210 Miscellaneous Intelligence, 



added much to that which was previously known. Alumina which 

 had been precipitated from alum by excess of carbonate of potash, 

 and well washed and dried, was made into a paste with powdered 

 charcoal, suajar, and oil, and heated in a crucible ; a porcelain tube 

 was filled with the hot product, and then placed in a long furnace ; 

 one end of the tube was connected with another tube, containing 

 fused chloride of calcium, and this, with an apparatus for the evolu- 

 tion of chlorine, the other end of the porcelain tube entered a small 

 tubulated receiver, furnished with a conducting tube. When the 

 apparatus was full of chlorine, the tube was made red hot, and the 

 evolution of chlorine continued. Chloride of aluminum was readily 

 formed ; it was long retained by the mass of matter, but a part 

 passed over into the receiver as a powder, whilst a little escaped 

 with the gas (oxide of carbon). After 1^ hour, the chloride ob- 

 structed the end of the tube, and on taking down the apparatus, 

 more than an ounce was found in that part of the tube within the 

 furnace. Part was an aggregated mass, and a portion in long crys- 

 tals. It easily separated from the tube, was of a pale yellowish green 

 colour, semi-transparent, lamellated, and distinctly crystaUine. In 

 the air it fumed a little, evolved the odour of muriatic acid, and 

 rapidly deliquesced. In water it dissolved rapidly, hissing and pro- 

 ducing great heat. Its fusing and vaporizing points are close 

 together. It may be preserved in naphtha: heated in it it liquefies 

 and collects at the bottom as a reddish brown hquid, on which 

 potassium has no action. 



The chloride may, however, be reduced by potassium in the fol- 

 lowing manner. Into a small platina crucilDle are to be put 9 or 10 

 small pieces of potassium, about the size of a pea each, and upon 

 the man equalnumber of similar pieces of chloride of aluminum ; the 

 crucible is then to be covered, and the cover confined by a platina 

 wire. Heat must be applied, gently at first : at the moment of re- 

 duction the crucible becomes red hot ; then the heat of the lamp is 

 to be increased, as the action diminishes, for a short time. The 

 reduced mass is generally completely fused, and is of a blackish 

 gray colour. When cold it is to be thrown into a large quantity of 

 water ; a gray powder separates, looking in the sunshine hke small 

 metallic plates : it is to be washed in cold water and dried. This 

 is aluminum. 



The reduction may be effected in a covered porcelain crucible. 

 Excess of potassium should be avoided, as it tends, when oxidized, 

 to dissolve a portion of the metal. The platina crucible used is but 

 little acted upon. 



Ahiminiini resembles platina in powder, but some particles have 

 the colour and splendour of tin. "When burnished, it looks like tin. 

 Rubbed in a mortar it appears to be compressible, unites into larger 

 scales with a metallic lustre, and leaves a metallic trace on the 

 mortar. When heated in the air, it burns violently into a white 

 hard mass of alumina. When the powder is thrown into a flame, 

 each particle burns brilliantly. Heated to redness, in pure oxygen, 



