ALUMINUM.* 



liv U. C. novEY 



The iorinal openiug of the great works of the Aluminum Brass aud 

 Brouze Company, at Bridgeport, Connecticut, makes it desirable, as a 

 preliminary, that we state a few facts about the unalloyed metal itself. 

 Quite learned men have indulged in wild talk about the metal, which 

 is more widely distributed over the globe than any other, being known 

 to exist in two hundred diflfereut minerals, including all granites and 

 common clays. 



The problem has been to extract the metal cheaply, and chemists of 

 every land have labored for a solution. (Ersted suggested a process 

 of obtaining aluminum by treating the chloride with an alkali metal. 

 Adopted by Woehler, and modified by Deville, the process was " a 

 reduction of the double chloride of aluminum and sodium by means of 

 j metallic sodium in the presence of cryolite." It was thus that Deville 

 ' was able to show at the Paris Exhibition in 1855, as the greatest of mod- 

 ern chemical wonders, a bar of what he styled "silver-white metal 

 made from clay." lie sold aluminum first at $15 an ounce, but in 1857 

 he reduced the price to $2 an ounce. Improvements cheapened the 

 jiroduct still further, so that Colonel Frishmuth, who cast the tip of 

 the Washington Monument in 1884, was able to furnish the metal in 

 bars at $15 a pound. In that year however he made only 1,800 ounces, 

 and the entire import was but 590 pounds. 



Prior to 1887, the entire amount manufactured annually was but 

 10,000 pounds, and it sold that year at $10 a pound. To get even this 

 small amount required the annual manufacture of 100,000 pounds of 

 the double chloride and 40,000 pounds of sodium. To cheapen these 

 two preliminary processes was essential to the cheap production of 

 aluminum. 



Hence the importance of the process patented by Mr. Hamilton Y. 

 Castner, June I, 1880, which was the first patent ever granted for an 

 aluminum process in the United States. Its special feature was a cheap 

 way of getting sodium. He reduced and distilled it in large iron cruci- 

 bles, raised automatically through apertures in the bottom of the fur- 

 nace, where they remain until the reduction is completed and the sodium 



* From the Scientific Ameiican. 

 H. Mis. 224 4G 721 



