1904-5.] THE CHEMICAL INDUSTRIES OF THE DOMINION. 171 
amorphous, and beyond this, the unchanged mixture.?8 A curious effect 
is observed near the core, where the temperature is highest; here are found 
crystals of carborundum, from which the intense heat has volatilized the 
silicon, leaving ‘‘skeleton”’ crystals of graphite, while the silicon, passing 
outwards oxidizes to silica, and often presents the appearance of spun 
glass. Silicon itself has been found in the cracks in the bed of the 
furnace.29 The carborundum is finally crushed, washed, and graded for 
the market. 
Carborundum has a lower specific gravity than emery, and finds its 
principal application in the manufacture of wheels, stones, razor hones, 
rubbing bricks for marble dressing, paper, and cloth. The Canadian works 
of the Carborundum Company were destroyed by fire in 1903 and have not 
been re-built. This plant was comparatively small, only operating 200 
horse-power. The factory, however, supplied the Canadian market, thus 
avoiding the payment of duty. The writer was informed by Mr. Acheson 
that most of the Canadian product was exported to Scotland, to be used 
there in finishing granite. The estimated cost of the crude crystals is 
2.5 cents per pound, that of the treated powder, 4.5 cents per pound, 
while the selling price averages 9 cents per pound. 
CoRUNDUM. 
The natural corundum industry of Ontario, which is of recent origin, 
is, however, now steadily growing in amount and value of output. The 
production of corundum in 1901 had a value of $53,115, and in 1903, 
$106,332, and in 1904 over $3,000,000.4° The chief producing company, 
the Canada Corundum Company, has just completed a new mill of greatly 
enlarged capacity, and the other operating concern, which formerly export- 
ed the corundum-bearing rock to the United States, after cobbing it merely, 
is now crushing and treating it on the spot. Two additional companies 
are in process of organization for producing corundum.*! 
To the Canada Corundum Company, of which Mr. B. A. C. Craig is the 
president, may be accorded the credit of having placed the natural cor- 
undum industry of Ontario on a firm basis. Craig Mountain is said to be 
the largest deposit of corundum in the world. The hardness of this sub- 
stance has long been known, and under the name of emery it has, in an 
impure state, been used as an abrasive agent. The product of this mine 
is said to contain from 95 per cent. to 98 per cent. crystalline alumina, 
and from letters the writer has seen, its hardness and cutting qualities seem 
(38) Illustrated Catalogue No. III., Carborundum Company, N.Y. 
(39) Electro-Chemical Industry, Vol. I., No. 2. 
(40) Letter from Mr. B. A. C. Craig, President of the Canada Corundum Company. 
(41) See 19 bis, 
