GLASS porcelain, the name given by many to a modern invention of imitating the china-ware with glass.
The method of making it, as given by Mr Reamur, who was the first that carried the attempt to any degree of perfection, is as follows.
The glass vessels to be converted into porcelain, are to be put into large vessels, such as the common fine earthen dishes are baked in; or into sufficiently large crucibles: the vessels are to be filled with a mixture of fine white sand, and of fine gypsum; or plaster stone, burnt into what is called plaster of Paris; and all the interstices are to be filled up with the same powder, so that the glass vessels may nowhere touch either one another, or the sides of the vessels they are baked in.
The vessel is to be then covered down, and luted, and the fire does the rest of the work: for this is only to be put into a common potter's furnace, and when it has stood there the usual time of baking the other vessels, it is to be taken out, and the whole contents will be found no longer glass, but converted into a white opaque substance, which is a very elegant porcelain, and has almost the properties of that of china.