April 1, 1896.] 



KNOWLEDGE, 



/ / 



burst of enthusiasm was, however, soon abated when the 

 enormous cost of production of the new metal was realized ; 

 but it was still confidently expected that, with further 

 work, the price of the element would soon be much 

 reduced, and that from being a laboratory curiosity it 

 would then become one of the principal items of metallur- 

 gical industry. Notwithstanding this stimulus to research, 

 and the very considerable attention that was devoted to 

 the elaboration of the processes then proposed for the 

 winning of the metal from clay, progress was by no means 

 rapid. Large sums of money were, however, subsequently 

 expended in the erection of factories in France, England, 

 Germany, and America ; and the older processes have 

 gradually been replaced by more modern methods, in 

 which the progress which has been brought about in the 

 perfection of electrical plant, coupled with the utilization 

 of the cheap energy of waterfalls, has been made to 

 contribute to the manufacture of this element, with the 

 result that, whereas in 185(i aluminium was worth £18 

 per pound, and in 18s6 still cost t"2 Ss., at the present 

 day it can be bought at about eighteen pence per pound. 

 The present low price of aluminium has naturally brought 

 it into the range of metals in general use, and has allowed 

 of its production in large quantities on a metallurgical 

 basis, so that its adoption for the most varied purposes 

 has at last been assured. Thei-e can be no doubt that last 

 year's output of the metal will be largely increased in 

 the near future, and that the dreams of the journalists of 

 185.5 wiU soon be more completely reahzed. The excep- 

 tional position of the metal renders it of interest at the 

 present time to review the history of its progress, as those 

 who are engaged in its development are confident that its 

 use will now rapidly extend in many directions, which have 

 hitherto been barred through difficulties attending not 

 only its economical production, but also in the removal of 

 impurities from the metal which aft'ect its durability, and 

 in want of knowledge which prevented the most suitable 

 alloys from being manufactured. 



The first attempts at the isolation of this metal from 

 ita oxide, alumina, were made by Davy in 1807, and some 

 years later by Berzelius ; but both of these distinguished 

 chemists failed to obtain any satisfactory result. In IS'24 

 Oerstedt endeavoured to decompose aluminium chloride 

 by means of potassium amalgam ; but although it seems 

 doubtful whether his experiments were successful, he has 

 the merit of ha%-ing first conceived of the idea that 

 an alkaline metal might be used for the reduction of 

 aluminium compounds. The celebrated chemist Woehler, 

 three years later, succeeded in decomposing anhydrous 

 aluminium chloride by means of metallic potassium, and 

 obtained the metal as a grey amorphous powder. He, 

 however, for some unknown reason, did not continue this 

 research until 1845, when, by passing the vapours of 

 aluminium chloride over heated metallic potassium, he 

 obtained a few grammes of the metal in globules as large 

 as a pin's head, which resembled metallic silver in appear- 

 ance. Owing to his extraordinary analytical skill, Woehler 

 succeeded in studying very completely the chemical and 

 physical properties of the metal with the small quantity 

 he had at his disposal. It seems strange that this careful 

 and valuable work of Woehler should not have at once 

 rendered its manufacture on a commercial scale possible ; 

 but it would seem that the cost of the alkaline metals 

 sodium and potassium at that time was almost pro- 

 hibitive, even for pure scientific research, and that 

 Woehler, therefore, had to be content with fully estabUsb- 

 ing the more important characteristics of this remarkable 

 element. It thus came lo pass that upwards of nine 

 years elapsed before the commercial importance of 



Woehler's work was realized. In February, 1854, Henry 

 St. Claire DeviUe communicated to the French Academy 

 of Science the discovery of a new metal, obtained by 

 decomposing aluminium chloride with potassium, being 

 unaware that Woehler had already practically gone over 

 the whole of this work nine years previously, illustrating 

 how incomplete at that date was the intercommunication 

 of scientific ideas in Europe. The publication of this 

 paper created considerable interest in Paris, and the great 

 importance of the discovery was at once reahzed. Deville, 

 aided by the support of the Academy and of the Emperor 

 Napoleon, who personally interested himself in the dis- 

 covery, again set to work ; and a few weeks later was 

 able to announce that he had succeeded in isolating 

 aluminium by the electrolysis of the fused chloride, and 

 accompanied the communication with the first piece of 

 aluminium foil which had ever been prepared. Almost 

 simultaneously Bunsen, in Germany, published an inde- 

 pendent account of the decomposition of aluminium 

 chloride by means of an electric current. The new metal 

 was thus prepared by two distinct processes : and it is only 

 due to the fact that, as the methods for the production 

 of electrical energy on a large scale at that time were 

 practically unknown, the chemical process for the isolation 

 of aluminium became the only one which was used com- 

 mercially until the last ten years. Deville himself fully 

 realized that the electrolytic process was destined to be 

 the future commercial one, but found it necessary to devote 

 his attention to cheapening the production of sodium for 

 use in the chemical method of extraction, which, owing to 

 its lower specific gravity, he thought was a more suitable 

 metal to employ than potassium. His improvements in 

 the manufacture of sodium resulted in its price falUng 

 from two thousand francs per kilo in 1855 to ten francs 

 per kilo in 1858. At the same time Deville investigated 

 the distribution of the metal in nature, with the view to 

 the production of compounds of alimiinium in as pure a 

 state as possible, and thus created the cryolite and beauxite 

 industries. Deville's sodium process was adopted in 1856 

 by a company which erected works at Amferville. near 

 Eouen, and in 1857 fresh works were completed at 

 Nanterre and Glaciere, the former being subsequently 

 transferred to Salindre. The first aluminium works in 

 this country were opened by F. W. Gerhard, in 185'.t, at 

 Battersea, and in 1860 Messrs. Bell Brothers began the 

 manufacture of aluminium at Xewcastle-on-Tjme, which 

 was continued there until ls74. 



Although the chemical process for the manufacture of 

 aluminium was thus the only one adopted at this period 

 for its commercial production, the electrolytic method was 

 slowly being elaborated at the hands of Le Chatelier, 

 Moiicton, Gaudin, K;i;,'enbusch, Derthaut, and other 

 chemists; and in ls80, when Siemens invented the electric 

 furnace which bears his name, it was soon seen that the 

 alternative process would eventually replace the purely 

 chemical one. The first commercial attempt to produce 

 aluminium by means of electrolysis belongs to Messrs. 

 K. H. and A. H. Cowles, of Ohio, whose process was tried 

 for some years at Milton, in Stafl'ordshire, and these works 

 have quite recently been acquired by the British Aluminium 

 Company. The Cowles process has, however, been over- 

 shadowed by the later invention of another American, 

 Ch. II. Hall, whose ideas have been adopted on a most 

 extensive scale by the Pittsbumh Keduction Company, 

 at Niagara. P-y these last two improvements the 

 manufacture of aluminium attains its mature stage of 

 development. 



Before discussing these processes at any length it may 

 be of interest to briefly state some of the chemical and 



