

MET; 



UM throat applied vertically at tli meUoentro; hence if th< 

 contra be n>.,r- the centre of gravity, the ihni-t tend* to re -adjust the 

 txis, and the equilibrium ia stable ; if ' ' i'..r : tends to carry 

 the aii farther from it- oriidnal place, unit the equilibrium is in- 

 table : if the two centra coincide, the equilibrium i" indilTcrvnt, We 

 ({ire u example : 



fly. 1. ABCD U a vertical *)*nrr iwetjon pa-uing through . tin- 

 centra of (rarity of a reeUn<ular Iwam flmtinu* on a fluid of twice its 

 apeeifle gravity, this section being t right angle* to the f.icro <>f the 

 beam ; therefore u H ) A n ; ami if g u = I \ n, g is the centre of 

 parity of the fluid displaced, ci g u the line <>f mi|>)H>rt, nml i: r tlie 



plaiK" Of flc Mt.lt i..'1. 



1. 



/'iff. 2 represent* the same body turned round iU centre of gravity 

 through a small angle ro/or 9. Let tt r = 1 ; we must find </, the 

 centre of gravity of rf CB, and draw</'o verticnl or perpendicular 

 to </, cutting the axis on in o the metaccntre. Let m, , be the 

 centre* of gravity of the portiona Kut,r uf, and h thut of the portion 

 MIPCB, then kg:ym:: solid Ko e : solid tare a; and h<i : i/'n 

 :: solid r ii/ : solid rorCB; but the solids Hue, j ../, are equal : 

 hence k'j : y ::k</ : /, therefore //' is parallel to mn. or nearly 



soliil 

 horizontal, and = ""i uj77^ nearly. Iow Bin = 2o t = J, and 



olid E o < - 4 x length, solid E r c B = 2 x length ; therefore yg' = 

 j X-T x = -r : but / fog' = ; therefore jro = J, or GO =3- : 



hence the equilibrium is instable. If the equilibrium were stable, the 

 times of the oscillations would be found by supposing the thrust 

 applied at o, the point i; remaining fixed. 



MKTACKTAMINK. [l'm>ni AMIXI:.] 



MKTACKT1C ACID. [PBOPioxic Afin.] 



METACKTOXE (V, t H m O t ). When a mixture of 1 ivrt of sugar 

 and 8 parU of lime is submitted to dwtillatiou, the teni|>enitim>, after 

 reaching 284* Fahr., rapidly riaes, and n very Bin.ill quantity of i/oiii- 

 l.iutible gas U liberated, accoinpniiied with a liijiior whicli ia n mixture 

 of acetone and metacetone. When water is added the metnuetone 

 enantea, which is to be rectified, the last portionn of the pnxluct 

 being preaerrwl. 



MeUcetone U a colourless liquid c.f nn agreeable odour. It br>ilR at 

 about 155* Kalir. ; doe* not mix with water, hut comliines with alcohol 

 and ether. It is not improbable that metacetone IK identical with 

 propione, a body which stands in the same relation to propionic acid 

 as acetone does to acetic acid. 



M KTA< -KTOX 1C AC'Il). [PRonoxic Aan.l 



JIKTACKTUNITKVL. [1'noi-u.. ('/, /.] 



5IKTACINNAMKIN. A m.xlititntii'.n <if Stynicin. [STVIIACIX.] 



MKTAKIIltKl'KOL. A very oxidiaable oil accmiinying fiirfurol. 



HRAOALUC ACID (C..II.O.): HnlMmic And is prepared by 

 tbepartialdecompointion of gallic acid by quickly heating it up to about 

 4Mr Kahr. Carbonic acid and water are formed and separated, and a 

 bbck, shining, t-Mtelew compound is left, which ia not dissolved ly 

 water, but U easily taken up by the alkalies ammonia, potash, and soda 

 in solution. It also decomposes the solutions of the alkaline carbonates 

 spelling the carbonic acid. Metagallate of potash gives insoluble pre- 

 cipiUlM with the salts of baryta and stroutia, and also with many 

 meUJlic ealu. [OiLLic ACID. 1 



METALDEHYDE. [OTBTL, HTDmroi or.] 



METALLURUY U the art of separating metals from their ores. The 

 pronsM. rary for erery meUl, and are described under each. 



METALS. The great characteristic of these well known substances 

 thtr lustrous appearance; it is indeed so constant an accompaniment 

 of them as to afford, under the name of nrtaUic tiutre, a standard of 

 description for the appearance of other bodies. 



MeUU, In the common acceptation of the term, are either compound 



imp]*. Brass, bronze, briunnia metal, Ac., are examples of compound 



nvtala; that U, they an composed of two or more simple metels 



Compound meUb are, however, always distinguished as ALLOTS, and 



"* "'"^Ppli.d only 



The metals or mrtollic elemental ore <xnu>id<-r.ilily ^n-att-r in 

 than the non-iiiftalliv eleiniMit..ry Imlivs, or metalloid*. In. -hiding om- 

 or two concerning whose metallic character there is a little <l.'ii>>t. the 

 whole iiitin'..er is aliout forty-nine. m- n iturally 



in the free or uncombined stnte, Win^ gi'iierally associated with lion- 

 luet-vllic elein :l ntiug nrrt. Some of I 1 with 



Hiich dirticulty that they are very rarely met with. e\i-tiux only in the 

 cabinets of the curious, or |.eiha;v< exclu<ively met with in the labora- 

 tories of the chemist* who sueeeeded in isolating them. Several of 

 them, lniwi ver. meh as KoM, .-ilver. co|>i>fr, iron, lead, tin. and inereury. 

 have been known from the most remote ages, and nearly nil t' 

 are well known to eliei, 



The physical chaiautcrs of tlie iiii'tnls. iiiehi.liii^ i-.ilour, relative 

 lutre. ductility, mallealijlity, tenacity, ix-lative \>rr 

 <U-ti.:r neea, struoture, power of conducting heat and elce- 



tricity. melting |H>int, and volatility, have already ln-en de^crilied nuclei- 

 MsT.li.->, in the XATI-BAI. HtaTOBT DrvtBIOH of this Cyclopoxlia, Their 

 e cTiditiim and distril ution in nature U also there dwelt U|*m, and the 

 ...-ficcu c,f metalloids ujKin them cursorily noticed. The inetluxls of 

 K<-|ianitiii;,' them fi-oni each other have been iven in the present 

 clivi.-ion of the work, under CM KM it u. ANAI i>i^ ; and it n<iw. tln>refoiv, 

 only remains to detiiil the various methods of classification that con- 

 venience or analogy has induced chemists and physicists to adopt. 



The following is a useful descriptive method of classiticatioii. and is 

 frequently employed in works on chemistry. 



] .Metals of the alkalies : 



Potawium Sodium 



J . M et-xls of the alkaline earths : 



Barium strontium Calcium 



3. Metals of the earths : 



Lithium. 



Aluminium 

 (ilucinum 

 Yttrium 

 Krbiutu 



Terbium 

 Zirconium 

 Thorinura 

 Cerium 



L*nthnnium 



IHclymium 



4. Oxitlible metals, whose oxides form powerful bases : 



Manpmew Cobalt llismuth 



Iron Copper I.tail 



Chromium Zinc Uranium 



Nickel Cadmium 



5. Oxidable metals, whose oxides form weak banes or acid. : 



Vanadium 



Tungsten 



Molybdenum 



Tantalum 



Niobium 



Fclopium ! 



lime-ilium .' 



Titanium 



Tin 



Antimony 

 AneBb 



Tellurium 

 Osmium 



6. Metals whose oxides are reduced by heat. Xoble metals : 



Gold 



Mercury 



Silx-or 



rintinum 



Palladium 

 Iridium 



Uullioniuin 

 Ithodium 



Analytical Clamijirnt!i> of the Mttalt. 

 Group I. 



Putuoium scccUum Lithium 



Barium 



Aluminium 

 Cliromium 

 (lucinum 

 Tharinum 



Iron 



Mangnncw: 



Gold 

 1'UUnum 



Group II. 

 Strontium Calcium 



Group III. 



Yttrium 

 Zirconium 

 Krhium 

 Terbium 



IV. 



Cobalt 

 NWul 



Mlrr 



Mercury 



Group V. 



liidium 

 Tin 



Group VI, 



Cadmium 



Copper 



Blimuth 



Cc'rium 



Di'iymium 



I.:inth;iniu:n 



Zinc 



I laniuni 



Ansnls 



Antin onjr 



Molybdenum 



Onnium 

 Palladlam 

 Bhudium 

 Buthenlum 



The following arrangement, founded upon the relative power of the 

 metals to decompose water and the action of heat upon their oxides, is 

 known as 



Thtnarfi Clatriflcation of the Mctalt. 



CLAM 1. Metals which decompose water with brisk effervescence at 

 82* Fahr. : 



PotasshaV 



Sodium 



Lithium 

 Barium 



Strontium 

 Calcium 



