MAGNESIA.

101

The term amianthus is now generally used to ex-press those varieties of the present species whichhave the softest, most flexible, and most easily sepa-rable fibres : asbestus is applied to those, the fibres ofwhich are comparatively brittle, harsh to the touch,and closely compacted. The gradations in the shadesof difference are too delicate to admit of description ;though the substances in which the extreme charac-ters reside differ at least as widely from each other,as the finest unspun silk from the most compactly fi-brous wood.

Loosely fibrous and flexible Amianthus.Specific gravity 0,9.

Fusible by the blowpipe to a blackish glass. Its se-parate fibres contract into a minute vitreousglobule when exposed to the flame of a candle;but a number taken together are only-made red-hot.

Silex ... 59Magnesia . . 25

Lime . 9

Alwnine . . 3

9G Mr. Cheuerix.

This probably is the substance from which werewoven those incombustible cloths, in which the an-cients sometimes burned the bodies of their dead.The appearance of cloth of amianthus differs not