MEL 



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M E N 



of garnet. It occurs in crystals, which 

 are dodecaedrons, with truncated edges. 

 Fracture conchoidal. Specific gravity 

 3' 73. Its constituents are silex 35 -5, 

 lime 32-5, oxide of iron 25*25, alumine 

 6-0, oxide of manganese 0'4. It is found 

 at Frascati, near Mount Vesuvius, in Bo- 

 hemia, and in North America. 



MELANO'PSIS. A genus of oval or oblong, 

 fusiform, univalves, belonging to the fa- 

 mily Melaniana, in Lamarck's arrange- 

 ment. Melanopsides are found both re- 

 cent and fossil ; they are distinguished 

 from Melanise by a notch in the aperture. 

 Fossil melanopsides are found in the shale 

 of the Wealden, at Pounceford. 



ME'LAPHYRE. A variety of black or py- 

 roxenic porphyry. 



MELASTO'MA. (from /*\ae, black, and 

 orojita, mouth, Gr.) A name given to a 

 genus of plants, belonging to the order 

 Melastomacea, from the fruit staining the 

 lips of a black colour. 



MELEAGRI'NA. A genus of bivalve mol- 

 luscans, known as the pearl-oyster. Me- 

 leagrina inhabit the Persian Gulf, the 

 coasts of Ceylon, the sea of New Hol- 

 land, the Gulf of Mexico, and the coasts 

 of Japan. It attains perfection nowhere 

 but in the equatorial seas, but in the pearl 

 fishery of the island of Ceylon it is the 

 most celebrated and productive. The 

 pearls are situated in the fleshy part of 

 the oyster, near the hinge. For one 

 pearl that is found perfectly round and 

 detached between the membranes of the 

 mantle, hundreds of irregular ones occur 

 attached to the interior of the shell, like 

 so many warts : they are sometimes so 

 numerous, that the animal cannot shut 

 its shell, and so perishes. 



ME'LITA. (from mel, honey, Lat.) Honey- 

 cake. A genus of echinites, belonging to 

 Catocysti. 



ME'LLATE. The name given to a salt, in 

 which the mellitic acid is combined with 

 any salifiable base. 



ME'LILITE. (from jus'Xt, honey, and Ai'0o, 

 a stone, Gr.) The name given to a rare 

 mineral from its honey colour. It occurs 

 only in very minute crystals, perfectly 

 regular and well-defined, but not larger 

 than a grain of millet- seed. These grains 

 are of a cubic or prismatic form ; their 

 surface is often coated with an oxide of 

 iron. They are glistening, semitranspa- 

 rent, and will scratch glass. Before the 

 blow-pipe, melilite fuses into a compact, 

 greenish, transparent glass. It occurs in 

 the fissures and cavities of lava. 



ME'LLITE. (from mel, honey, and XiQog, a 

 stone.) Honey-stone. The Honigstein 

 of Werner ; La Pierre de mi el of Bro- 

 chant ; Pyramidales Melichron-Hartz of 

 Mohs. This mineral was first observed 



in Tlmringia, where it occurs associated 

 with brown coal. It is of a honey-yellow 

 colour, whence its name, and is usually 

 crystallized in small octahedrons, whose 

 angles are often truncated. Fracture 

 conchoidal. Lustre shining or splendent. 

 By friction the crystals acquire a weak ne- 

 gative electricity. They are more or less 

 translucent, or even transparent, and ex- 

 hibit double refraction. Mellite may be 

 distinguished from amber by its weak elec- 

 tricity, and double refraction. It consists 

 of mellitic acid 41 -0, alumina 14 '10, 

 water 44*8. 



MEMBRANA'CEOUS. (membranaceus, Lat.) 

 Resembling membrane. In botany, a 

 membranaceous leaf has no distinguish- 

 able pulp between the two surfaces. 



MEMBRA'NEOUS. (membraneux, Fr. mem- 

 branoso, It. membraneus, Lat.) Con- 

 sisting of membrane. In this and the 

 preceding word may be observed the dif- 

 ference between words ending in aceus 

 and eous : those ending in aceous express 

 a resemblance to a material, those ending 

 in eous indicate the material itself. 



ME'MBRANE. (membrana, Lat. membrane, 

 Fr. membrana, It.) The membranes of 

 animals are thin semitransparent bodies, 

 which envelope certain parts of the body, 

 to which they furnish a covering for their 

 support and protection. Membranes are 

 modifications of cellular texture, the sur- 

 faces of the plates cohering so as to obli- 

 terate all the cellular interstices, and 

 being impervious to fluids. Membranes 

 also line the interior of all the large cavi- 

 ties of the body ; these membranes, after 

 lining the sides of their respective cavi- 

 ties, are reflected back upon the organs 

 which are enclosed in those cavities, so 

 as to furnish them with an external co- 

 vering. Thus the bowels are covered by 

 the peritoneum, the lungs by the pleurae ; 

 nevertheless, in consequence of these 

 membranes being reflected, the lungs and 

 bowels may be said to be external to their 

 investing membranes. 



ME'MBRANOUS. Consisting of membrane ; 

 resembling membrane. In botany, ap- 

 plied to leaves of an extremely thin and 

 pliable texture ; also to stems of a delicate 

 substance, composed of several thin mem- 

 branes laid one over the other ; opposed 

 to herbaceous. 



ME'NACHINE. (from Menachan, a valley 

 in Cornwall.) The name given to a new 

 metal, discovered by Mr. Gregor, to 

 which the name titanium is now more ge- 

 nerally applied. The menacMne of Gregor 

 and the titanium of Klaproth are the 

 same substance, and to Gregor is owing 

 the merit of the discovery. See Tita- 

 nium. 



ME'NACHANITE. (from Menachan, in 



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