The New Student's Reference Work/Asbestos

Asbes'tos, an incombustible mineral of a flax-like, fibrous texture, composed of silica, magnesia and lime, and usually occurring in veins in highly metamorphic rocks. The sources of supply of commercial asbestos are deposits of two distinct minerals: one a variety of serpentine known as chrysotile; the other a variety of amphibole. The Canadian product, which is much prized, is of the chrysotile variety, and is chiefly found in the Thetford district, in the province of Quebec. There the more expensive grades have a value of from $150 to $250 a ton, though the mill fibre or paper stock commands but $30 or so a ton. The yield of the Canadian product in 1910, was 75,678 tons, valued at $2,458,929, the most of which was exported, only a small part being reserved for home consumption. The sources of the supply in this country are the states of Georgia and Wyoming, Idaho and Vermont. In the United States the yield in 1910 was but 3,693 short tons, valued at $68,357. The foreign sources, besides Canada, where asbestos is found, are Australia, Russia, Corsica and the Tyrol. The uses are now many to which asbestos is put, among them the manufacture of fireproof clothing, lining felt, theater curtains, etc., where protection is sought from fire; it is also in use for incasing steam pipes, pistons, hot-air joints and furnace pipes as well as for lampwicks, gas stoves and fireproof safes. It is valuable also for its heat-retaining properties. The ancients were familiar with asbestos, making use of it to envelope corpses on the funeral pyre, so as to retain the ashes.