Chemical Observations upon Spathic Iron. 247 



This experiment is without doubt decisive; but does not 

 the small quantity of zinc obtained in the distillation prove 

 that the zinc was in very small proportion in the earthy 

 substance ? This supposition appears to me to be confirmed 

 bv what M. Dize himself says of the action of prussiate of 

 lime upon the nitric solution, and without excess of acid, 

 before it had been precipitated by the alkali : — it had a saline 

 taste ; the prussiate of' lime did not injure irs transparence ; 

 and, he adds, the oxalic acid and sulphuric acid do not de~ 

 monstrate the presence of lime. Besides all this, M. Dize 

 had nothing in view but to prove that the specimen of 

 Bayen contained zinc. I repealed the same experiment 

 upon a piece of spathic iron from Vaunaveys, and I ob- 

 tained the results of M. Dize, with the exception of the 

 zinc, of which I did not perceive the least traces ; which 

 proves, that if some of these ores contain a little, at least 

 they do not all contain it. 



According to what I have said, we may consider the fol- 

 lowing as the certain results of Bayen's experiments. 



1st, That the iron is combined in the spathic iron with 

 carbonic acid. 



2d, That the quartz and the calcareous carbonate some- 

 times obtained in the analysis of this ore do not enter into 

 its composition. 



Almost at the same time with Bayen (in 1774) Bergman 

 published upon the white ores of iron ; he proves in this 

 work, that the iron in these ores is in the same degree of 

 oxygenation as in green vitriol : as for lime, although he 

 obtained some very great differences in the. quantities which 

 he procured from different specimens, he determined to re- 

 gard it as a constituent part of spathic iron. The method 

 which he employed in order to extract it, consisted in cal- 

 cining the ore, reducing it to fine powder, and agitating it af- 

 terwards a long time with diluted nitric acid. The fixed al- 

 kali was then employed in order to precipitate from this acid 

 a white earth, which he ascertained to be lime. I do not 

 think, however, that this result can invalidate the conclu- 

 sion which Bayen deduced from his experiments. In fact, 

 it may be rightly judged, that in a long course of labours of 

 Q 4 the 



