12 PROCEEDINGS OP THE ACADEMY OP 



rate existence and peculiar characters. To Oerstedt belongs the credit of first 

 preparing the chloride of aluminium, from which compound W5hler, in 1827, 

 succeeded in first eliminating the metal. Wohler first obtained aluminium in 

 the form of a grey powder, by heating gradually in a porcelain crucible over a 

 spirit lamp equal volumes of metallic potassium and chloride of aluminium ; 

 other chemists, by slight modifications of this process, have obtained aluminium 

 in the form of the grey powder, as first obtained by Wohler. 



To M. Sainte Claire Deville belongs the credit for first improving the process, 

 so as to produce aluminium in such quantities that its characters as a metal 

 could be fully investigated. M. Ste. Claire Deville used in his process sodium 

 as a substitute for potassium. (It requires 39 parts of potassium to produce the 

 same reductive effect as 23 parts of sodium.) At the time of his first experi- 

 ments sodium was worth one hundred dollars per pound ; he so improved the 

 process for making this metal as to reduce the price to ninety cents per pound. 



At this time the chloride of aluminium was regarded witli sodium as a curi- 

 osity of the laboratory ; it was then produced in small quantities by heating 

 alumina mixed with coal, in a porcelain tube, and passing over it a current of 

 dry chlorine gas. 



M. Ste. Claire Deville made farther improvements in this process, so as to 

 make it in an apparatus as large as a gas retort and in quantities proportional, 

 at a price of twenty-five cents per pound. To produce the reaction of sodium 

 with the chloride of aluminium was the most difficult point of the entire process. 

 M. Ste. Claire Deville used for the reduction the distillation of the chloride of 

 aluminium over the sodium, which was placed in trays of copper enclosed in a 

 tube. The temperature developed by the reaction is very great if the current 

 of the chloride of aluminium be rapid ; by this process it was found that it re- 

 quired at least ten pounds of sodium to produce one pound of aluminium, (part 

 of the aluminium produced being destroyed at its formation by the scorise,) 

 when by theory it required only two and a half pounds. This great loss of 

 sodium and the difficulties in conducting this reaction on a large scale, were 

 very great objections to the process. 



All the aluminium at the Paris Exhibition was made by this process, and it 

 was from a portion of this that M. Regnault made his investigations, and in 

 which he found copper and iron. The copper came from the trays in which 

 the reduction was made. The presence of these metals in small quantities will 

 account for the peculiar physical properties which he ascribed to aluminium. 



Circumstances having interrupted M. Ste. Claire Deville in the experiments 

 which he was making on a large scale, the subject rested for a while here. In 

 the meanwhile Heinrich Rose suggested and made experiments with cryolite, 

 (a fluoride of aluminium and sodium,) and gave his views that this mineral was 

 a valuable substance from which to produce aluminium. 



Wfthler made experiments also with cryolite, and arrived at conclusions 

 somewhat similar to Heinrich Rose. They both succeeded in producing 

 some of the metal, but the results were not entirely satisfactory. 



M. Ste. Claire Deville again resumed his experiments, but instead of distilling 

 the chloride of aluminium on the metallic sodium, as in his first experiments, 

 he fused in a crucible, in the manner pursued by Rose and Wohler, using, 

 however, with the double chloride of aluminium and sodium and the metallic 

 sodium, the fluoride of calcium, (fluor spar,) or some cryolite as a flux. This 

 experiment of M. Deville was very satisfactory, and the reduction in accordance 

 with the theory. 



While these experiments were in progress in Europe, similar ones were being 

 made in this country by Mr. Alfred Monnier, in Camden, N. J. ; to him credit is 

 due for having first made aluminium in the United States. Having had oppor- 

 tunities for examining his processes for making the double chloride of aluminium 

 and sodium, metallic sodium, and the modes of reduction, melting and refining the 

 aluminium, the conclusion is satisfactory that the discoveries of science have 

 been successfully applied to render the manufacture of this metal an industrial 

 art. 



[Jan. 



