^I^ ANALTSIg OF IRON SPAR. 



portion of man- radical vinegar a little diluted, and the whole was dissolved, 

 gauese. except some traces of black oxide of manganese. The so- 



lution was slightly coloured. On heating it, it became co- 

 lourless; and though the precipitate was a little inereased 

 by this ebullition, it could not be weighed on account of 

 the smallness of its quantity. 

 The supposed As the iron might contain manganese, it was calcined with 

 Konoxuecon- ^^^^g^jp pdash, which thus acquired a very deep green co-* 

 cf manganese, lour. The calcination with potash was repeated, till the in- 

 tensity of the colour was so far diminished, as to render it 

 almost certain, that the whole of the manganese was separ-f 

 ated. The alkaline liquor being saturated by an acid, the 

 manganese was precipitated by ammonia. It weighed 4 

 parts. The true results therefore of the analysis of white 

 iron spar are 



Eeal compo- Iron... •• • OQ* 



rient parts of Manganese • • • 4-5 



white iron spar. Carbonic acid united with the iron • • fi'S 



Carbonate of lime 41 



Carbonate of magnesia* • • • • • 7 



Loss and water of crystallization • • • • 17'2 



Pyrites 3 



100 



Examlnalion of the products of analysis of black iron spar» m 



Preceding ana- The five parts of carbonate of lime mentioned above, be- 

 lysis of black -^ treated in the same manner, were found to contain 

 iron spar exa- » .• i> i • i 



raaied. merely an atom of lime, the quantity ot which was too 



small to be estimated. They consisted almost wholly of 

 magnesia, with a little manganese. The iron too contained 

 a perceptible quantity of manganese, which could not be 

 separated from it completely but by repeated calcination 

 v/rlh caustic potash. 



The following alterations therefore must be made in the 

 results of the analysis of the black iron spar. 



> - 'eal conipo- Oxide of iron and of manganese. • • • 64 



aenijHcts, Carbonic acid united with the 2 metals l6'Q 



Carbonate of ujagnesia 3 



•Loss and water of crystallization. • • ' l6'l 



100 



XIL 



