inox. 



ISOCARDIA. 



**-' =" It ocean in modified oblique prisms, 

 vita clwrin in oo direction highly perfect It is also found radiated, 

 reeufonn, and globular, or u coatingn. The colour U.deep blue to 

 men. TbecrystaU an usualiv green at right angles with the vertical 

 axis. and blue parallel to it The streak u bluish ; lustre pearly to 

 vilmxu; trautparent to translucent ; opaque on exposure. The thin 

 Uminc are flexible. U ban a hardu* 1'S to 2 ; and a specific gravity 

 of K6. It has the following composition : 



Protoxide of Iron ..... 42-4 

 Phosphoric Acid ..... 28-7 

 ^ ...... 28-9 



- 100 



It lose* it* colour before the blow-pipe, dissolves in nitric acid, and 

 affords water in a glass tube. It is found with iron, copper, and tin 

 ores, and sometimes in clay or with boe iron-ore, at St. Agnes in 

 Cornwall, Bodrnmais, the gold mines of VorospaUk in Transylvania, 

 and in the United States. 



Kmt Irm-Kortk is an earthy variety. It contains 30 per cent, of 

 phosphoric acid. A oglarite is a variety from Anglor in France. 



Trtpkptau is an anhydrous phosphate of iron ami manganese, with 

 some lithia. It occurs at Bodenmais in Bayern in cleavable masses of 

 greenuh gray or bluish colour. 



CbcoxdK is a handsome mineral. It is a phosphate of iron and 

 alumina, and occurs in radiated silky tufts of a yellow or yellowish- 

 brown colour. It U found on brown iron-ore in Bohemia, and with 

 specular iron in the United States. 



CarjJioridmtf u another yellow phosphate of iron from Greenland. 

 It occurs in reniform missus, 



Gnat Irv+Shmt (Krauriir), AUumulite, MttancUor, and Bcraunite 

 are names of phosphates of the peroxide of iron. 



Ojctlait of Iron occurs native. It is a soft yellow earthy mineral 

 of rare occurrence. It blackens instantly in the flame of a candle. It 

 is found in Bohemia, and is supposed to have resulted from the decom- 

 position of those orders of such plants, such as Cactacta, which 

 naturally contain oxalic acid. 



HUiralo of Iron. -Then are several compounds of silica and oxide 

 of iron, none of which are of special interest in an economical point 

 of view. 



Hrdftiberyile is a variety of Augite. [AuoiTE.] 



Iron Ckrytolite differs from ordinary chrysolite in containing oxide 

 of iron in place of magnesia, 



/topyrt u a black glassy amorphous mineral found in granite. 

 [Isorru.] Its hardnera is 6 to 6-5. 



Yrnile (called auw Licrrilc and /Irailr) occurs in rhombic prisms, 

 often with the sides much striated or fluted ; its colour is black or 

 brownish-black, streaked with greenish or brownish-black. Ita hard- 

 Ms* U S'5 to 9. Its specific gravity, 3 '8 to 4*1. It contains from 50 to 55 

 per cent, of oxide of iron, with 14 per cent of lime, and 29 per cent. 

 of silica. It fuses to a black globule. It is found in the island of 

 Elba in Urge crystallisations, also in Norway, Siberia, and Silesia. 



At Cumberland, in Rhode Island, Yenite occurs in slender black or 

 brownish-black crystals in quarts ; al<o in Essex county, New York. 



The following are hydrous species, giving off water when heated in 

 a tube before the blowpipe : 



tivMlroxiu and Pinytule are earthy, almost like clay, of a yellowish 

 or greenish colour. 



Ckloropol U a much harder species, of a greenish-yellow or plstachio- 

 greeo coolour. 



Tknriuyitt, Kiieoclllt, and Xirtcanite are other allied 



Grtrn Earlk include* different compounds of a green earthy appear- 

 ance. The linen Earth occupying cavities in amygdaloid is near 

 cUorite. U U a silicate of the peroxide of iron, with some potash, 



, and water ; often with other ingredients. 

 I Qrtm (i.-ain, of the Grtcnnnd of New Jersey consist of 



! .61-5 



Alumina 0-4 



Protoxide of Iron ... .24-8 



Potosfc 8-98 



WsUr 7-7 



99-66 



H*img*rilt,Groiut*{iH r . Anlkoadrrilt, I'olykydrite, SidtrotchMile, 

 OkamoMt, HJpnom'tanr, and Xylile are names of dark brown or 

 bsacfc SMCMS> 



CnctdtliU has a nbroiu structure much resembling Aiibcstui, and 

 is frequently called Blue AAalut. Colour lavender-blue or leek- 

 green. It* hardness U 4, and its specific gravity is 32 to 3'3. It U 

 found in Hootbern Africa. 



Pynnutlat occurs in hexagonal prisms, with a perfect basal 

 cbavafs ao.1 a prariy surface. Colour pale liver-brown, grayish, or 

 grvrainb. IU bardMM U 4 to 4'5; and iU specific gravity 8-8. It 

 witoia* 14 per cent of chlorid ; of iron, and gives off fumes of 

 fUtiu acid Wfor* the Mow | ; i,. 



/r /ro/ifr i* a hydrous silicate of the oxide* of iron and mangn 

 we, forming iacnuUtioM at a mine near Freyberg, 



Annalrt of Iron. Vvbt On occurs in cubes of dark green to 

 brown sod red colours. It U of an adamantine litntra, not very 

 distinct, with a gneoi.h or brownish streak. It* hardness is 2'5 ; 



and its specific gravity 8. It is a hydrous arsenate of the peroxide 

 of iron, containing 38 per cent of araeuic acid. It is found in the 

 mines of Cornwall; also in France and Saxony. 



Scorodite crystallises in rhombic prisms, modified. It U of a pale 

 leek-green or liver-brown colour, with a colourless streak, of a vitreous 

 lustre inclining to subadamantine ; nubtransparent, or nearly opn<iue. 

 Its harduess u 3'5 to 4'8. Specific gravity, 3'1 to 3'3. Scorodite ia a 

 hydrous arsenate of the peroxides of iron, containing 50 per cent of 

 arsenic acid. It comes from Saxony, Carinthia, Cornwall, and Brazil. 

 It occurs in minute crystals near Edenville, New York, with ar 

 pyrites. The name of this species is from the Greek, nape*** 

 (garlic), alluding to the odour before the blow-j>i]>f. 



Iran Sinter ia a yellowish or brownish hydrous arsenate of the 

 peroxide of iron, containing but 30 per cent, of araenic acid. 



Arteno-Siderite is another fibrous arsenate, containing 34 per cent 

 of arsenic acid. 



Sympletitt is a blue or green mineral, supposed to be an arsenate of 

 the protoxide of iron. Its crystals are right rhoniboidal, with a 

 perfect cleavage. It hardness if TO ; and its specific gravity is 2'96. 

 It is found in Voigtland. 

 (Dana, Mineralogy.) 

 IRON-BARK-TREE. [EucAi-TPTCS.] 



ISAHIA, a genus of fungi, belonging to the division TrtcAotpOrei, 

 and the tribe Itareii of Ldveilld. It is characterised by a compound, 

 solid, capitulated, or elongated receptacle. The species are found 

 parasitic upon caterpillars and the larva: of various insects. Robin 

 enumerates the following species : 



7. Eleuteratorum has been found upon the CaraduiUc in the autumn 

 of the year. 



/. Jloccota, upon the larva; and chrysalides of Bomlnjx Jacobaa. 

 /. itrigota, upon the chrysalides of A'oc'ua L'tailon. 

 1. arachnophila, upon small spiders belonging to the genus (icomclra, 

 iu the autumn. 



/. Uprota, on the chrysalides of Noclva, intlabilit. 

 I. Tarlarica, observed by Robin upon an unknown spider, in the 

 autumn. 



/. cratta, upon decaying chrysalides. 

 /. tphtcophila, upon a dead hornet 

 /. exoleia, upon the larva of a moth. 



/. Aranearum, an American species, found on spiders in Carolina. 

 7. Sphingum, ako found in America, upon the caterpillars of the 

 silk-worm moths. 



7. giyanlea, found upon a Mygale in the island of Cuba, 

 (Robin, H'utairt ffalurellei da Ytgitaux Paratitet.) 

 1S.VT1S, a genus of Plants belonging to the natural order Crticlfera: 

 and the tribe liatiileie. It has a laterally compressed pouch, 1 -celled, 

 1 -seeded, valves keeled, eventually separating. 



7. tincloria, Dyer's- Wood, has the radical leaves oblong, crcnate ; 

 pouch abrupt, smooth, thrice as long as broad. It is a rare plant in 

 cultivated and waste land iu Great Britain. It yields a blue dye, long 

 known and used in this country. It was before the introduction of 

 indigo a plant of considerable importance commercially, ;url it was 

 extensively cultivated in Somersetshire, especially about Glastonbury, 

 which town received its name from the Celtic word ' Glas,' signifying 

 ' Blue.' The ancient Britons are said to have painted their bodies 

 with the blue colour obtained from this plant 

 (Habington, Manual of Britith Botany.) 

 ISCHY'ODUS, a genus of Fossil Fishes included in Chiauera by 



A :.--]/. 



ISERINE. [TITANIUM.] 



ISINGLASS. [(JKIATIS.] 



ISNARDIA, a geuus of Plants named by Linnicun in memory of 

 M. Antoine Dante lauard, member of the Academy of Sciences. It 

 belongs to the natural order Onagraceoe, and has a 4-cleft calyx, 

 4 petals, 8 stamens, and a filiform style, with a clavato or cruciform 

 stigma. There is one British species of this geuus. 7. paltuilrit has 

 a procumbent rooting glabrous stem, opposite ovate acute ! 

 terminating in a petiole, axillary solitary sjssile flowers, with tlie 

 petals absent It is found in pools and marshes in Europe, Siberia, 

 and Persia, and in Sussex in England. 



7. alttrnifolia has an erect branched stem, alternate leaves, ralhcr 

 scabrous on the margin.", and hoary benenth. It is a native of Virginia 

 and Carolina, in marshy places, and has oval yellow jictal*. The root 

 is used as an emetic, and is called Bowman's Root 



None of the species of this genus possess qualities which entitle 

 them to cultivation except in botanical gardens. They may however 

 be reared in a hot-bed, and then planted in an open border iu a moist 

 situation. 



(Don, Dichlamydcoui Plantt; Babington, Manual uf Briiith 

 Botany.) 



ISOCA'RDIA, a genus of Conchiferous MoUuica, I/inniciiH pUc< d 

 the form under Chama ; Bruguicre arranged it among tli- ' 

 Lamarck, who made it the lust of the genera of his Cardiaedes, 

 c]i:i rated it from the last-mentioned genus, giving it the generic name 

 at the head of this article. Mr. G. I!. Sowerby (' Genera of Recent 

 and Fossil Shells') thinks that thin separation was effected with good 

 reason, because the involute divaricate umbones of Iiocardia, and its 

 consequently dichotomous ligament running iu each valve to the i>oint 



