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thin coat of fibrous or granulated porcelain upon the glassgave opacity 3 of the pieces of a close smooth texture,some, tho' pretty thick, were semitranfparent, and others,tho’ thinner, were opake.

In the fibrous state of the porcelain, it is considerablyhard 3 much more so than the glass it was made from, andthan any of the common kinds of porcelain. It freelyand plentifully strikes fire with steel, which green glassdoes but in a low degree. It cuts common glass, as indeedone piece of glass in some measure will another 3 but nei-ther any of the common kinds of glass, nor the file whichcuts them, make any mark on the fibrous porcelain.Even when the change is scarcely visible on the surfaceof the glass, the external part is found sensibly harder tothe file than the internal.

It perfectly resists both acid and alkaline liquors, neitherpermitting them to transude through it, nor being at allcorroded by them.

It bears vicissitudes of considerable degrees of heat andcold, so that vessels of it may be plunged at once, withoutany danger of their cracking, from freezing into boilingwater. It may likewise be set on burning coals, withmuch less precaution than any of the porcelains or earthenwares used for containing liquids.

In a moderate white heat, it melts, so as to be easilydrawn out into long slender strings, which appear femitranf-parent, and, on breaking, prove not fibrous as before,but of a vitreous smoothness like white enamel. Some ofthe melted pieces were considerably bright or glossy, somehad no glossiness, and all of them proved softer than beforethe fusion, seeming, though very compact, to be littleharder than common green glass.

It does not however melt near so easily as the glass Itself.When the cementation has been continued no longer than4 till