760 PROCEEDINGS OF THE AMERICAN ACADEMY. 



volatilization and fusion of carbon, a result first announced by Professor 

 Silliman in 1822 and since confirmed by Despretz, who by the union of 

 the heat of six hundred carbon couples arranged in numerous parallel 

 series, and conjoined with the jet of an oxyhydrogen blowpipe, and the 

 heat of the midday sun, focahzed by a powerful burning glass, succeeded 

 in volatihzing the diamond, fusing magnesia and silica, and softening 

 anthracite. The diamond is also softened, and converted into a black 

 spongy mass resembling coke, or, more nearly, the black diamond found 

 in the Brazilian mines.' 



" The fusion of carbon referred to is evidently a mistake, but 

 the softening of anthracite probably resulted in its conversion into 

 graphite. 



" Upon the advent of the dynamo during the decade of 1870 to 1880, 

 the ability to obtain and maintain electric arcs with comparative ease 

 made it possible to apply electric heat to larger crucibles and to note 

 again the facile conversion of impure varieties of carbon into graphite. 

 The first attempts to apply electric heating on a fairly large scale in 

 obtaining new products was probably made by Cowles in 1886, using a 

 mixture of carbon, aluminum oxide, and copper, whereby there was 

 formed aluminum bronze. The operation involved the direct reduction 

 of alumina by carbon, but if this were attempted without the presence 

 of the alloying metal copper, a carbide of aluminum was formed and no 

 metal. The operation was rather irregular and uncertain, but stands as 

 a worthy effort to apply electricity to smelting. The heat generated 

 in the mass of materials undergoing the operation was due to resistance 

 of innumerable contacts throughout the granular mass, to the resist- 

 ance of the materials themselves, and possibly to incipient arcing 

 between particles. 



" Mr. Edward G. Acheson, who had assisted in the Edison Menlo Park 

 laboratory in 1880 and 1881, and who up to 1889 and later was con- 

 nected with electric work as engineer, superintendent, or electrician, 

 began to work with an electric furnace in 1891. In attempting to 

 'impregnate clay with carbon under the influence of the high heat 

 obtainable with the electric current ' he noted the formation of a few 

 bright specks. After having separated out one of these specks, he 

 drew it across a pane of glass, which it scratched and cut. This led to 

 further experiments, and a small vial of the new product was taken to 

 New York under the name 'carborundum,' as Mr. Acheson was labor- 

 ing under the mistake that it contained carbon and corundum. It was 

 tried in cutting diamond, with the result that the diamond cutter 

 bought the material at thirty cents per carat. This was the first sale 

 of the new abrasive. On finding that it was the silica in the clay 



