274 



TRANSACTIONS OF THE 



Examination of Specimen JVo. 32. 



Specimens of siderose or lithoid spathic iron accom- 

 panied the other substances. These ores are found in 

 nodules of different sizes, varying in form ; they are 

 known frequently as kidney ores ; when broken, have a 

 blue brown colour, conchoidal fracture. Sometimes 

 lamellar crystals of the sulphuret of zinc are found ou 

 breaking a mass. When reduced to powder, its colour 

 is grey ; submitted to heat, developes the odour of 

 bitumen. 



The ore is composed as follows : 



Carbonate of protoxide of iron (protoxide of iron 



49.42, carbonic acid 30.94) 

 Sand and argile, ..... 

 Carbonate of lime, ..... 

 Carbonate of manganese, carbonate of magnesia, 



bitumen and water, .... 



100.00 



One hundred parts of this ore, then^ yield 38.2 of 

 metallic iron. 



80.36 

 12.60 

 1.00 



6.04 



