MAN 



[278] 



MAE 



considerable quantity, it communi- 

 cates to glass or enamel a violet or 

 purple colour. The ores of man- 

 ganese present much diversity in 

 their external characters. All min- 

 erals containing any considerable 

 quantity of this metal, when melted 

 with borax and a little nitre, yield 

 a violet glass. One of the ores of 

 manganese, known by the name of 

 Slack Wadd, is remarkable for its 

 spontaneous inflammation when 

 mixed with oil. 



MA'NON. A genus of zoophytes, found 

 in the cretaceous group and deter- 

 mined by Goldfuss. 



MANGANE'SIAN GAENET. Grenat man- 

 ganesie of Brongniart ; Spessartine 

 of Beudant. A species of garnet 

 occurring massive and in dodeca- 

 hedral crystals variously modified. 

 Colour, a deep hyacinth or brown- 

 ish red : edges slightly translucent. 

 Fusible before the blow-pipe, and 

 when fused with borax and nitre 

 the borax is violet. According to 

 Klaproth it contains protoxide of 

 mangane 35-00, silica 35 '00 alu- 

 mine 14-25, protoxide of iron 14'00. 

 It occurs in granite. 



MANTE'LLIA. A genus of fossil ani- 

 mals belonging to the chalk deposit. 

 This genus is thus described, " an 

 animal with a fusiform or ramose, 

 root-like pedicle, a stem and body 

 formed of tubuli, anastomosing in 

 a basket-like, texture, with open- 

 ings on the internal surface." The 

 name Mantellia has also been given 

 by Adolphe Brongniart, to a genus 

 of cycadeous fossil plants found in 

 the petrified forest of the Isle of 

 Portland. 



MA'EBLE. (ma/rlre, Fr. marmo, It. 

 marmor, Germ, marmor, Lat.) Any 

 limestone possessing sufficient hard- 

 ness to take a polish may be called 

 marble. Many of these are fossil- 

 iferous; but statuary marble, which 

 is also called saccharine limestone, 

 from its possessing a texture re- 

 sembling that of loaf-sugar, ' is 



devoid of fossils, and belongs to the 

 metamorphic series of rocks. 



MA'EGAEATE. A compound of mar- 

 garic acid with potash, soda, or 

 some other base, and so named 

 from its pearly lustre. 



MAEGA'EIC ACID. An oleaginous acid, 

 formed from different animal and 

 vegetable fatty substances. 



MAEGAEITA'CEOTTS. ^Reflecting the pris- 

 matic colours like mother-of-pearl. 

 Shuckard. 



MA'BGAEITE. A mineral, of a grayish- 

 white colour, occurring massive 

 and in thin crystalline laminae, 

 intersecting each other in all direc- 

 tions. It bears some resemblance 

 to silvery mica. 



MA'EGAEODITE. A mineral which is 

 described as forming the matrix of 

 black tourmaline. 



MA'EGIN. (marge, Fr. mdrgine, It.) 

 The border or edge. In conchology, 

 the whole circumference or outline 

 of the shell in bivalves. 



1. In conchology, having a promi- 

 nent margin or border. 



2. In entomology, when the sharp 

 edge is margined, and surrounds 

 the surface with a narrow border. 



MAEGINE'LLA. An ovato-oblong, 

 smooth univalve, with a short 

 spire. The lip thickly marginated 

 on the outside. The base of the 

 aperture slightly notched; the 

 columella plicated. Marginella 

 differs from Yoluta in the reflection 

 of its outer lip. Eecent Margi- 

 nella3 are found in sand and sandy 

 mud. Several fossil species have 

 been discovered in the calcaire 

 grossier. 



MA'EINE'ALLTT'VIIJM. Shingle thrown 

 up by the sea ; materials cast upon 

 the land by a wave of the sea, or 

 those which a submarine current 

 has left in its track. 



MAEI'NE VEGETA'TION. The marine 

 vegetation, says Sir C. Lyell, is 

 less known; but we learn from 



