268 ENAMELS 



solid lump, with which to dress tho edges of buff and glaze wheels. The ingredients 

 should bo thoroughly incorporated by stirring tho mixture whilst fluid, after wlm-h it 

 is frequently poured into water, and thoroughly kneaded with the hands, and rolled 

 into lumps before it has time to cool. The emery-cake is sometimes applied to tho 

 wheels whilst they are revolving; but the more usual course is, to stop the wheel 

 nnd rub in tho emery-cake by hand. It is afterwards smoothed down by tho 

 thumb. 



Emery-paper, or patent razor-strop paper, is an article in which fine emery and glass 

 are mixed with paper-pulp, and made into sheets as in making ordinary paper; tho 

 emery and glass are said to constitute together 60 per cent, of tho weight of the paper, 

 which resembles drawing-paper, except that it has a delicate, fawn colour. The emery - 

 paper is directed to be pasted or glued upon a piece of wood, and when rubbed with a 

 little oil, to bo used as a razor-strop. 



In 1842, Mr. Henry Barclay took out a patent for a method of combining powdered 

 emery into discs and laps of different kinds, suitable to grinding, cutting, and polishing 

 glass, enamels, metals, and other hard substances. The process of manufacture is as 

 follows : Coarse emery-powder is mixed with about half its weight of pulverised 

 Stourbridge loam and a little water or other liquid, to make a thick paste ; this is 

 pressed into a metallic mould by means of a screw-press, and after having boon 

 thoroughly dried, is baked or burned in a muffle or close receiver at a temperature 

 considerably above a red heat and below the full white heat. In this case, tho clay 

 or alumina serves as a bond, and unites the particles very completely into a solid 

 artificial emery-stone, which cuts very greedily, and yet seems hardly to suffer percep- 

 tible wear. 



Superfine grinding-emery is formed into wheels exactly in the same manner as the 

 above, but the proportion of loam is then only one-fourth instead of one-half that of 

 the emery. Those emery-stones, which are of medium fineness, cut less quickly, but 

 more smoothly than the above. 



Flour-emery, when manufactured into artificial polishing stones, requires no uniting 

 substance, the moistened powder is forced into the metal mould and fired ; some por- 

 tions of the alumina being sufficient to unite the whole. These fine wheels render the 

 works submitted to them exceedingly smooth, but they do not produce a high polish 

 on account of the comparative coarseness of the flour-emery. 



A similar method has been adopted by Mr. F. Ransome at the suggestion, we 

 believe, of Mr. Bessemer for the production of emery wheels, by a process similar to 

 that employed for the production of artificial stone by the use of silicate of potash, as 

 a cementing material for the finely-divided emery. 



Under the name of ' metalline,' Messrs. Bond, Russell, and Fisher, of Newport, 

 Monmouthshire, patented a preparation of blast-furnace slag, which they proposed to 

 introduce as a substitute for emery. See CORUNDUM. 



ElVTERYLITE. A micaceous mineral associated with the emery of Asia Minor. 

 It is identical with margarite. 



EMETINE. An organic bark obtained from the ipecacuanha root. 



EMPATAGE. A French term for the combination of an alkali with the fatty 

 acids. 



EMPLECTITE. An ore of bismuth, called also Tannenite. See BISMUTH. 



EIVIPYREAIi AIR. The name given to oxygen gas shortly after its first dis- 

 covery. Scheele, in his 'Experiments on Air and Fire,' says: 'Since this air 

 (oxygen) is absolutely necessary for tho generation of fire, and makes about one-third 

 of our common air, I shall henceforth for shortness call it empyreal air (literally fire- 

 air}. The air which is unserviceable for the fiery phenomenon, and which makes 

 about two-thirds of common air, I shall for the future call/ow/ air (literally corrupted 

 air\' Chemical Observations and Experiments on Air and Fire. By Charles William 

 Scheele. Translated by J. R. Forster, LL.D., F.R.S. 1780. 



E1VTPYREIT1VIA. The smell produced by fire applied to organic matters, chiefly 

 vegetable, in close vessels. Thus, empyreumatic vinegar is obtained by distilling 

 wood at a red heat, and empyreumatic oil from many animal substances in the 

 same way. 



EMULSIKT. The vegetable albumen of the almond. See Watts's Dictionary of 

 Chemistry.' 



EltfAMELS (Emaux, Fr. ; Schmelzglas, Ger.) are varieties of glass, generally 

 opaque or coloured, always formed by the combination of different metallic oxioYs. 

 to which certain fixed fusible salts are added, such as tho borates, fluates, and phos- 

 phates. 



Tho ancients carried the art of enamelling to a very high perfection, and we occa- 

 sionally find beautiful specimens of their work. Then, as at present, each artist made 



