M I L 



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M I N 



crystals, and in masses with a radiated 

 structure. 



MI'LLEPEDE. > (millepeda, Lat. from mille, 

 MI'LLIPEDE. $ a thousand, and pes, a 

 foot.) Insects whose body is generally 

 cylindrical ; segments half membrana- 

 ceous and half crustaceous, each half 

 bearing a pair of legs ; antennae seven- 

 jointed, filiform, often a little thicker 

 towards the end. These are called milli- 

 pedes. The millipedes belong to the 

 necrophagous tribe, or those which de- 

 vour dead animals, or any other pu- 

 trescent substances. Rev. W. Kirby. 

 MI'LLEPORE. (from mille, a thousand, and 

 porus, a pore.) A genus of lithophytes 

 of various forms, having the surface per- 

 forated with numerous small pores or 

 holes. In millepores the cells are more 

 minute and closer than in madrepores, 

 and do not exhibit any star-like radia- 

 tions. 



MILLE'PORITE. A fossil millepore. 

 MI'LIOLA. ) A genus of microscopic mul- 

 MI'LLIOLA. $ tilocular univalves, not larger 

 than a millet seed, with transverse cham- 

 bers, involving the axis alternately, and 

 in three directions ; the opening small 

 and circular, or oblong, at the base of the 

 last chamber. Several species are found 

 to exist on our shores, and many recent 

 specimens have been obtained, on fucus, 

 near the island of Corsica. 

 MI'LIOLITE. }The fossil Miliola. So nu- 

 MILLI'OLITE. $ merous are these minute 

 fossils in the neighbourhood of Paris, 

 that some species of them form the prin- 

 cipal part of the masses of stone in some 

 of the quarries. The remains of such 

 minute animals as the milliola, have 

 added much more to the mass of ma- 

 terials forming the earth's crust than the 

 bones of the mammoths, whales, and 

 hippopotami. 



MI'LLSTONE. Called also Burrhstone. The 

 Quartz agathe molaire of Haiiy ; Silex 

 meuliere of Brongniart. The exterior 

 aspect of this mineral is somewhat pecu- 

 liar, being full of pores and cavities, 

 which give it a corroded and cellular 

 appearance. It occurs in amorphous 

 masses, above the marine sand and sand- 

 stone. Sometimes the mass is compara- 

 tively compact, and the cavities small 

 and not numerous ; but in all specimens 

 these cavities or cells are to be found. 

 Millstone is of a white or greyish colour ; 

 sometimes with a tinge of blue or yellow ; 

 when unmixed it is pure silex. It con- 

 tains no organic remains, and in the 

 order of superposition of the formations 

 in the neighbourhood of Paris, it consti- 

 tutes the ninth horizontal bed, counting 

 from the chalk upwards. In is of great 

 use for making into millstones, from 



which circumstance it has obtained its 

 name. 



MI'LLSTONE GRIT. The name given to a 

 siliceous conglomerate, composed of the 

 detritus of primary rocks. It has been 

 thus named from some of the strata hav- 

 ing been worked for millstones. It con- 

 stitutes one of the members of the car- 

 boniferous, or mountain limestone group. 

 The millstone grit forms a bed of consi- 

 derable thickness in some situations, 

 amounting to three or four hundred feet ; 

 in others it is of very limited extent ; 

 and sometimes it is wholly wanting. 



MINERAL ADIPOCI'RE. A fatty bitumi- 

 nous substance occurring in the argilla- 

 ceous iron ore of Merthyr, in Wales. It 

 is insoluble in water, and fuses at a tern- 

 perature of 160. When cold it is in- 

 odorous, but on being heated gives out a 

 bituminous odour. 



MI'NERAL CAOU'TCHOUC. A variety of bi- 

 tumen, intermediate between the harder 

 and softer kinds. It sometimes much 

 resembles India rubber in its softness 

 and elasticity, from whence it derives its 

 name, and like that removes the traces of 

 the pencil, but, at the same time, it soils 

 slightly the paper. Colour brown, red- 

 dish-brown, or hyacinth-red. Specific 

 gravity from 0'90 to 1-23. It burns with 

 a bright flame, emitting during its com- 

 bustion, a bituminous odour. It occurs 

 near Castleton, in Derbyshire. 



MI'NERAL CHA'RCOAL. A fibrous variety 

 of non-bituminous mineral coal. 



MI'NERAL WA'TERS. Waters impregnated 

 with mineral substances. 



MINERALIZA'TION. The process of con- 

 verting into a mineral some body not 

 previously such. 



MI'NERALIZE. To convert into a mineral. 



MI'NERALIZER. That which converts a 

 substance into a mineral. Metals are 

 combined with oxygen, sulphur, &c. by 

 which their peculiar metallic properties 

 are more or less disguised ; in this case 

 the metal is said to be mineralized, and 

 the oxygen or sulphur is termed the mi- 

 neralizer. 



MI'NERALS. (minerale, Lat. mineral, FT. 

 minerale, It.) Those bodies which are 

 destitute of organization, and which na- 

 turally exist within the earth or at its 

 surface. The term fossil is usually ap- 

 propriated to those organic substances 

 which have become penetrated by earthy 

 or metallic particles. 



Minerals have been divided into two 

 kinds ; simple, or homogeneous, and com- 

 pound, or heterogeneous. Simple minerals 

 appear uniform and homogeneous in all 

 their parts. They do, in fact, usually con- 

 tain several different elementary systems ; 

 but these are so intimately combined, and 



