MET 



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MET 



They are fusible, or capable of being ren- 

 dered fluid by a heat attainable by artifi- 

 cial means ; becoming again solid on cool- 

 ing. They are elastic, hard, heavy, and, 

 generally, sonorous. Some of the metals 

 possess a degree of taste and smell. All 

 the metals are expansible by heat, and 

 their degree of expansibility appears to 

 bear a relation to their fusibility. 



META'LLIC. ^ (metallicus, Lat. metal- 



META'LLICAL. S lique, Fr. metallico, It.) 

 Partaking of metal ; consisting of metal ; 

 containing metal ; resembling metal. 



META'LLIC BEDS. Some metallic ores oc- 

 cur in the form of beds in primary and 

 transition rocks. Iron ore often forms 

 beds of considerable thickness, interposed 

 between rocks of gneiss, slate, and mica 

 slate. The difference of external character 

 is so great between a pure metal and an 

 earth, that it is difficult to conceive, at 

 first, how metallic matter can form beds 

 interstratified with earthy rocks ; the dis- 

 coveries, however, of modern chemistry 

 have shown, that metallic and earthy mi- 

 nerals are closely allied. BakewelL 



META'LLIC LU'STRE. One of the most 

 conspicuous properties of metals is a par- 

 ticular brilliancy which they possess, and 

 which has been called the metallic lustre. 

 There are other bodies which apparently 

 possess this peculiar lustre, as, for exam- 

 ple, mica, but in them it is confined to 

 the surface, and accordingly disappears 

 when they are scratched, whereas it per- 

 vades every part of metals. 



META'LLIC ORE. Metals existing in the 

 state of an oxide, or a salt, or united with 

 a combustible, are called ores / and this 

 term is, by analogy, extended to the na- 

 tive metals and alloys. 



The earthy, stony, saline, or combusti- 

 ble substance, which contains the ore, or 

 is only mingled with it, without being 

 chemically combined, is called the gangue, 



. or matrix, of the ore. 



Metals and their ores, are sometimes 

 disseminated in other rocks; sometimes 

 they form irregular masses of various 

 sizes, and sometimes they constitute beds ; 

 but more frequently they are found in 

 veins, either filling the whole vein, or 

 mixed with various saline and earthy mi- 

 nerals. They appear to be the production 

 of every period, but more frequently exist 

 in primary and transition, than in secon- 

 dary rocks, or than in alluvial earths. 



META'LLIC O'XIDE. A metal combined with 

 any proportion of oxygen, is called a 

 metallic oxide, provided it do not possess 

 the properties of an acid. Hence the 

 same metal, by uniting with different 

 quantities of oxygen, often furnishes two 

 or more oxides, which differ in colour and 

 in other properties. All metals must be 



converted into oxides, before they can 

 combine with acids to form metallic salts. 

 Cleaveland. 



META'LLIC SALTS. Those salts which have 

 a metallic oxide for their base ; carbonate 

 of lead is an example. 



METALLIC VEINS. " Perhaps," says Mr. 

 Bake well, " the reader may obtain a clearer 

 notion of a metallic vein, by first imagin- 

 ing a crack or fissure in the earth, a foot 

 or more in width, and extending east and 

 west on the surface, many hundred yards. 

 Suppose the crack, or fissure, to descend 

 to an unknown depth, not in a perpendi- 

 cular direction, but sloping a little to the 

 north or south. Now, let us suppose each 

 side of the fissure to become coated with 

 mineral matter, of a different kind from 

 the rocks in which the fissure is made, 

 and then the whole fissure to be filled by 

 successive layers of various metallic and 

 mineral substances ; we shall thus have a 

 type of a metallic vein. Its course from 

 east to west is called its direction, and 

 the dip from the perpendicular line of 

 descent, is called its hading." Introduc- 

 tion to Geology. 



While plain countries are utterly desti- 

 tute of all indications of metallic veins, 

 there are few mountainous countries ia 

 which they do not occur in abundance. 



" There is a remarkable circumstance," 

 says Prof. Phillips, " in the distribution of 

 metallic veins in the same class of strati- 

 fied rocks, a peculiarity depending on 

 local influences ; such, that while the 

 slates of Cornwall near the granitic erup- 

 tions, yield tin and copper, and the Snow- 

 donian slates, and those of Coniston 

 Water Head yield copper ; those of 

 Loweswater, Borrowdale, Patterdale, and 

 Caldbeck fells yield lead, or lead and 

 copper." 



METALLI'FEROUS. (from metallum, metal, 

 and fero, to produce.) Yielding metal, 

 as metalliferous deposits, metalliferous 

 districts, metalliferous veins, metalliferous 

 dykes, &c. 



METALLIZA'TION. The act, or process, of 

 forming into a metal. 



METALLO'GRAPHY. (from ftsraXXov, a 

 metal, and ypaQfj, a description.) A 

 treatise on metals, or metallic substances. 



META'LLURGY. (from ^eraXXov, a metal, 

 and Ipyov, a work, Gr. metallurgie, Fr.) 

 Some authors comprehend under this 

 term, the whole art of working metals, 

 from the glebe, or ore, to the utensil ; in 

 which sense assaying, smelting, refining, 

 parting, smithery, gilding, &c., are only 

 branches of metallurgy. Others restrain 

 metallurgy to those operations required 

 to separate metals from their ores. 



METAMO'RPHIC. (from fierd, trans, and 

 p,op<j>r}, form, Gr.) A term proposed for 



