R O N. 



e%ed. Occurs in concentric, lamellar, diftiiifl concretions. 

 Streak )ello\vifh-bro\vn. It is ferai-hard, pafiing to foft. 

 Not very brittle; eafily frangible. Sp. gr. 5-207. 



It exliibit?, before the blow-pipe, the fame appearances 

 as the lall fubfpecies. Subjoined are tiie refults of two 

 analyfes of it ; the former by Vauqiielin, the latter by 

 MiJliiiirhof : 



Iron 



Oxygpa 



/iiurnine 



Silex 



Water 



This mineral is fuppofcd by WLrncr to occur in the fe- 

 t-oad fletz lijne-ftone, and in clay-beds. 



It is found in France, Switzerland, Franconia, HeiTia, 

 Siiabia, tlie duchy of Wirtemberg, and Dalmatia. In the 

 latter country, it is f^d to be ufed by tiie inhabitants inllead 

 «f lliot. 



The greater part of the Fren<!i iron is extrafted from 

 this fubfpecies. It yields, in the large way, from 30 to 40 

 per cent, of metal. 



Sp. 11. Bog iron ore. Rafer.eifivjlzhu Lc fir liinoneux. 

 Ferrttm ochraceum cefpit'it'ium. 



Werner divides this into three fubfpecies ; morafs ore, 

 fwamp ore, and meadow ore. 



Subfp. 1. Morafs ore. — Colour yellowifh-brown. It is 

 fometimes friable, and fometimes approaching to coherent. 

 When the latter, it occurs mafiive, corroded, and in grains. 

 The former varieties confill of dully particles. Luilre dull. 

 Fratlure earthy. Fragments indeterminate, blunt-edged. 

 Soils confiderably. Is meagre to the touch, and light. 



Subfp. 2. Swamp ore'. — Colour dark yellowifh-brown, 

 fometimes pafTing to yellowifh-grey. Occurs corroded, 

 veficular, and amorphous. Luilre dull, fometimes {lightly 

 glimmering. Frafture earthy, pafiing to line-grained, un- 

 even. Fragments indeterminate, blunt-edged. Streak light 

 yellowilh-brown. Very foft ; feftile. Eafily frangible, 

 lind moderately heavy. Sp. gr. 2.944. 



Subfp. 3. Mtado'iv ore. — Colour, when frefh broken, 

 blackidi-brown, paffing fometimes to yellowirti-brown, and 

 brownilli-black. Occurs maffive, in grains, tuberofe, per- 

 forated, and amorphous. Externally it is rough and dull. 

 In the interior it varies from fliining to glimmering ; luilre 

 refinous. Frafture conchoidal, pafiing fometimes to 1 mall- 

 grained, uneven, and earthy. The conchoidal varieties 

 have the brightell luilre. Fragments indeterminate, blunt- 

 edged. Streak light yellowilli-brown. Soft ; brittle. 

 Very eafily frangible, and heavy. 



Bog-iron ore in general blackens before the blow-pipe, 

 without melting. It enters into ebuUition witli borax, and 

 produces a glafs of a dirtyiJli yellow colour. The only 

 member of the fpccies that appears to have been fubjefted to 

 analyfis is the meadow ore : and it is conltituted, according 

 <o the information of M. D'Aubuiflbn, of 

 Peroxyd of iron 61 



Pirox^'d of mangancfe 7 

 Silex 6 



Aluminc 2 



Volatile matter 19 



Pholphoric acid 2.y 



Liiue, fulphur, andlofs 2.j 



100 Aniialcs de Chimic, t, 75. 



The volatile matter, which fo conllantly forms a part of 

 the refults quoted from this chemill, almoil exclufively con- 

 fills of water ; and it v;as with a view, indeed, of afcertain- 

 ing the proportion of this ingredient, that his analytical 

 labours were principally commenced. He fuppofes it to be 

 an effential conllituent of the different minerals he ha.-; ex- 

 amined, and propofes to arrange them under the clafs of 

 hjilrats. 



The prefent fpecies is fmeltcd in fome of tlie countries 

 that afford it, and yields, in the large way, from 30 to 35 

 per cent, of metal. 



It occurs in the neweil formations, and is conceived to be 

 continually depDlitcl in marlliy places, from the evaporation 

 of the water that has held it in folution. The preceding 

 fubfpecies are products of this procels at different flage."; ; 

 and the order in which they are arranged is indicative ol the 

 date of their formation. 



It is found in different parts of the Highlands of Scot- 

 land, the Hebrides, Orknies, and the Shetland iflaiids. 

 Poland and Prufiia contain confiderable quantities of it ; as 

 alfo do Brandenburg, Courland, Livonia, and Lithuania. 

 Its occurrence is more frequent in the northern than in the 

 fouthern countries of Europe. 



Sp. I 2. Blue iron earth. Bhne etfenerik. Le fr terrcux 

 hleu. Ferrum ochraceum caruhum. 



Before it has been expofed to the air, its colour is greyifh- 

 white, but afterwards becomes indigo-blue of different 

 fliades, and fometimes fmalt-blue. Occurs mafiTive, and 

 diffeminated ; and is compofed of dull, dully particles, 

 wliic4i are friable and cohering. Soils flightly. Feels 

 meagre, and is moderately heavy. 



Before the blow-pipe, it becomes of a reddib-brown, and 

 afterwards melts into a brilliant black gk bule, which tinges 

 borax of a deep yellow. It is readily loluble in acids. 

 Bergmann had fuppofed it to be a native Prujfan-blue ; and 

 it has received a place in many mineralogical fyllems, under 

 that name, from the fame belief: but an analytical examina- 

 tion of it by Klaproth feems to prove it to be a compound 

 of phofphal of iron and aluminc. 



It occurs in nells in clay-beds, among.^ bog-iron ore, 

 and incruding turf and peat. 



It is found, under the latter circumflances, in the Shet- 

 land iflands ; it alio appears in Icclar.d, Saxony, Silclia, 

 Swabia, Bavaria, Poland, Siberia, Ruflia, and Sweden. 



Sp. 13. Pitchy Iron ore. Efcnpecherez. Ftr phofphate. 



Colour pitch-black, paffing fometimes into blackifh- 

 brown, and even deep reddifh -brown. Occurs maffive. 

 Surface earthy, and dull. Internally it is ghltening ; lull.'-e 

 refinous. Frafturc foliated, conchoidal, and foinetim.es 

 line-grained, uneven. Fragments indeterminate, tolerably 

 fliarp-cdged. Opaque ; femi-hard ; brittle. Not very 

 eafily frangible, and moderately heavy. Sp. gr. 3-956. 



It melts eafily before the blow-pipe, and forms a black 

 enamel. According to Vauquelin, it confilU of 

 Phofphoric acid 27 



Oxyd of iron 3 i 



Oxyd of manganefe ^ z 



Is found near I.,imogcs, in France. 



Sp. 1 4. Green iron earth. Griine eifenerde. he fer tcr- 

 reux -vert. Ferrum ochraceum •vlncU. 



This IS divided into two fubfpecies; friable green iron 

 earth, and coherent green iron c rih. 



Subfp. I . Friable green iron earth. — Colour fidcin-green. 



Occurs niafSve, aiid dilferainated j and«oalills of particles 



6 whiw b 



