216 ANNUAL OF SCIENTIFIC DISCOVERY. 



" The thorough working of aluminum by means of the chloride of this metal 

 and sodium, is, by general admission, a great acquisition to science. M. 

 Deville procured chloride of aluminum by causing the chlorine to react on a 

 mixture of alumina and coal-tar, previously calcined. The operation was 

 effected in a gas retort with extraordinary facility and perfection. The result 

 of M. Deville's observations is that the action of the chlorine is procured upon 

 a layer of one, or at most, two decimeters of the mixture, so that the absorp- 

 tion of the gas is always complete. The condensation of chloride of aluminum 

 is effected in a chamber of masonry lined with tiles. This chloride is so com- 

 pact that it can be seen on the table, of considerable density, and composed 

 of yellow crystals. Very slightly ferruginous, it is purified completely during 

 the process of extracting the aluminum, in which its vapor passes over iron 

 filings heated to 400 C. or thereabout. The sesqui-chloride of iron, as volatile 

 as the chloride of aluminum, is changed by contact with the iron, and becomes 

 comparatively very fixed. The vapor of the chloride of aluminum rising from 

 the apparatus forms colorless and very transparent crystals. Sodium is being 

 prepared the meanwhile in large and small vessels with remarkable facility. 

 Having studied with particular care the influence of temperature on the sur- 

 faces exposed to heat, and the activity of the vapor of sodium as it escapes 

 from the apparatus, M. Deville is convinced that, by properly regulating the 

 relation between the heated surfaces and the section of tubes from which the 

 sodium issues, one could procure this metal at a moderately high temperature, 

 about that, perhaps, of the melting point of silver. Already even the cylin- 

 ders are much less heated than are the vessels used in the manufacture of 

 zinc. The author is now employed in producing sodium in continuous ap- 

 paratus. 



" As to the reaction of the chloride of aluminum upon the sodium, that is 

 done in metallic tubes, the form and management of which are not yet suffi- 

 ciently scientific. In this particular there is yet something deficient. It will 

 be remarked undoubtedly, that in the details above there is no mention of the 

 very reduced price which Messrs. Dumas and Balard have promised. It ap- 

 pears that, for the present at least, this price is still very high, and very far 

 from being what would be considered the net cost, as stated by us condition- 

 ally, of the agents necessary to extract the aluminum. Moreover, M. Dumas 

 has not explained himself formally concerning the price even of the new metal, 

 and he has anticipated too much hi this respect. Now, if sodium, which cost 

 lately 1,000 francs a kilogram, should rise 30 francs more, as it requires 

 three times the quantity of that to extract a proportion of aluminum, it will 

 be perceived that this laiter article would not be so accessible as they would 

 have it seem, not to mention other particulars which increase the expense. 

 Still there is reason to believe that a factory of aluminum established at Mar- 

 seilles, turning to account the chlorine of muriatic acid, which is produced in 

 superabundance, and the aluminum of certain deposits in the vicinity, could 

 offer this precious metal at a price sufficiently low to place it shortly among 

 the more common ones. . 



" Scarcely has aluminum been ranked among metals before, independently 

 of the unexpected service it will render as such to the arts and sciences, it 



