52 ANALYSIS OF MAGNETIC IRON-ORE. 



to exist in the iron-ores, and which the imperfect 

 processes of the manufacturers do not enable 

 them to separate. Hence the analysis of the ores 

 of iron comes to be an object of very great im- 

 portance ; as it is the only method of acquiring a 

 knowledge of the nature of the foreign substances 

 which alter the nature of iron. Were they once 

 accurately known, it might be possible to vary 

 the processes of the manufacturers, so as to enable 

 them to get rid of these foreign substances alto- 

 gether, and thus make all iron of exactly the 

 same quality : or it might be possible to substi- 

 tute those which are least injurious for those which 

 are most injurious, or, by introducing at once two 

 foreign substances of opposite natures, to neutra- 

 lize the effect of both. 



Magnetic iron, which constitutes the subject of 

 this paper, is one of the most abundant and im- 

 portant of all the iron-ores. It has been usually 

 conceived to consist of pure oxides of iron, and to 

 this purity, the goodness of the iron obtained from 

 it has been ascribed. 



The only chemical experiments on this ore, with 

 which I am acquainted, were made by Bucholz ^. 

 He ascertained the action of muriatic and suU 

 phuric acids upon it, and concluded from his ex- 

 periments, that it was a mixture of black and red 



* Gehlen's Journal, 2d series, vol, iii, p. 106. 



