ASBEN, a country of Central Africa, known also as Aix, which see.

ASBESTOS, or ASBESTUS (from cla-Parroc, 2112CO228221- able), is a variety of the amphibole or hornblende family of minerals, and akin to tremolite, actinolite, and common hornblende. The chemical composition of the whole family is chiefly silica, magnesia, alumina, and ferrous oxide, but varies considerably. Those containing most iron are most easily fused. Asbestos consists of fine crystalline elastic fibres, with a silky lustre, varying in colour from white to grey and green, and derives its name from being specially indestructible by fire. A single fibre of it fuses to a white enamel, but in the mass it is capable of resisting ordinary flame, and has on this account been regarded from ancient times as a most interesting substance. Woven into cloth it forms a fireproof texture, which, to be purified, requires only to be thrown in the fire ; gloves, napery, towels, handkerchiefs, and even dresses have been woven of it ; and it is said that the ancients used to wrap the bodies of their dead in asbestos cloth to keep their ashes separate from those of the surrounding funeral pile. There are several varieties of asbestos : - (1.) Anzianthus is the rarest and most delicate kind, its fibres being beautifully white, flexible, long, and regularly laid. It is found in the centre of the older crystalline rocks, in the Pyrenees, the Alps of Dauphiny, on Mount St Gotthard, in North America, in the serpentine of Sweden, in the Ural Mountains, Silesia, and New South Wales. But the most beautiful specimens come from Tarantaise, in Savoy, and from Corsica, where it is somewhat abundant. (2.) Common Asbestos is not so light, either in colour or weight, as amianthus, and is more splintery, inflexible, and irregular in structure. It fuses with difficulty before the blow-pipe into a black scoria. It is found in serpentine rocks in Anglesea, in Cornwall, and also in several parts of Scotland, as Glenelg, in Inverness. (3.) Mountain leather and Mountain cork are other varieties, where the fibres are less flexible and regular than in either of the above. Their colour is brown or a dirty white. Mountain leather is in thin flexible sheets, and mountain cork is so named from being not unlike common cork, and so light as to swim on water. It is found in Lanarkshire. (4.) Mountain wood is a soft, tough, opaque, brownish-coloured variety of asbestos, much heavier than the last, and melting to a black slag before the blow-pipe. It is found in Tyrol, in Dauphiny, and iu Scotland at Glen Tilt, Portsoy, and Kildrummy.

It has been often proposed to employ asbestos in the manufacture of fireproof goods, and it was at one time thought that an important industry would grow out of . this application. In early times the art of weaving amianthine cloth was its chief application, and was much valued. It was accomplished by weaving the fibres along with those of flax, and then heating the cloth in a furnace to destroy the flax. It is said that Charlemagne had an amianthine tablecloth, which he used to have arown into the fire after dinner for the astonishment of his guests. Chevalier Aldini, of Milan, is said to have had a complete dress - cap, gloves, tunic, and stockings - made of asbestos cloth, and to have made very successful experiments with it by way of testing its protective power for firemen. Advantage has also been taken of its qualities for the performance of clever tricks of fire-handling. Paper has been manufactured from asbestos, and would prove invaluable, in ease of fire, for charters and other important documents, were it not that the paper is rather tender for use, and that the writing disappears after a red heat. Its feeble consistency has proved the chief obstacle to its use in textile fabrics. More success has attended its employment for fireproof roofing and flooring, for non-conducting envelopes of steam pipes, and for the packing in fireproof safes. Lately it has been proposed to use it for piston-packing in steam engines, it Lavine, been found to exceed in durability any material hitherto employed - a matter of importance, especially in the case of marine engines that have to be at work night and day on long voyages.