10 



The Scottish Naturalist. 



in Lancashire, Cumberland, and Gloucestershire. It has also been 

 found in Derbyshire, Somersetshire, Devonshire, and Cornwall. 



9. Brown Haematite, or the brown oxide, or hydrous oxide of 

 iron, easily recognisable by its brown or yellow colour. This is the 

 ore most common in France j and is almost exclusively that used 

 in supplying the Belgian iron-works. It is abundant in Oolite in 

 Northamptonshire, and also in North America. Bog iron ore 

 belongs to this member of the group. 



10. Pitchy Hydrate of Iron, which is found in old mines, and 

 is supposed to be the product of the decomposition of mispeckel, 

 or arsenical iron pyrites, its composition being very similar, though 

 the analyses differ slightly. 



11. Yenite or Lievrite, a rare mineral, composed of peroxide of 

 iron and silica ; this is found in Elba, Norway, Sweden, Siberia, 

 and the Western States of America. 



12. Carbonate of Iron, comprising : 



(a) Spathic or Sparry Iron Ore, so called from its compara- 

 tively pure or crystallized form, is pretty widely distri- 

 buted throughout Prussia, Austria and Spain. It 

 occurs in metallic veins in Cumberland, Devonshire and 

 Cornwall — in crystalline form in the Devonian rocks of 

 Somersetshire and North Devon, and in the carbonifer- 

 ous limestones of Northumberland. It is also found 

 in America. 



(h) The Compact Carbonate of Iron or Clay Iron of the CoaL 

 formation, which is divided into two great divisions. 



( 1 ) The Argillaceous (earthy). 



(2) The Blacl'band or Carbonaceous. 



The first of these has a peculiar connection with the brown 

 haematite of France, and Northamptonshire. The Grey Carbon- 

 ates of the Lias and Oolite are changed into hydrated peroxide or 

 brown haematite, when the quantity of earthy matter is small, 

 and carbonates of magnesia and lime are present. When the 

 carbonate of magnesia is largely present, as a bi-carbonate, it dis- 

 places the carbonate of lime ; and the analysis shows that in the 

 brown haematites the lime is not present, but that the iron and 

 manganese, which formerly existed as carbonates, are now changed 

 into oxides, by the action of water,, and partly, it may be, by the 

 atmosphere. 



This Argillaceous Ironstone forms the chief deposits of Nor- 



