Dr Colquhoun on the Argillaceous Ore of Iron. 233 



gillaceous carbonate of iron, and of those extrinsic bodies 

 which are commonly found mechanically associated with it, it 

 appears that there is no principle of relation discoverable 

 among the ingredients, but that they always vary according 

 to accident or locality. It could furnish, therefore, neither 

 pleasure nor instruction to group together the details of all 

 the numerous analyses of this ore, which are supplied by the 

 researches of Descostils and others in the pages of the An- 

 nales des Mines, and in some of the later volumes of the 

 Journal des Mines ; unless, indeed, we were at the same time 

 to recapitulate the mineralogical description, and geological 

 history of each particular specimen analyzed. Such a com- 

 pilation could only prove a tedious exemplification of the 

 general facts already stated, respecting the composition of the 

 ore. But as only two analyses of any British specimen of this 

 ore have ever been published, one of an ore from Colebrook 

 Dale in Shropshire, examined by Descostils, and one of an 

 ore from the vicinity of Bradford in Yorkshire, examined by 

 Mr Richard Phillips, there seems to be a want of detail upon 

 this subject, which it cannot fail to prove desirable in some 

 measure to remove. Had this, the most important of all our 

 minerals, only been as rare as it is common, or had it been 

 brought from a great distance abroad, instead of being found 

 in a happy profusion at home, it is hardly to be doubted that 

 long ere now the pages of our scientific journals would have 

 exhibited an accurate exposition of its nature and history. 

 But since the fact is so, it is at least an agreeable task to fur- 

 nish some materials towards supplying the deficiency, and 

 therefore the following mineralogical analyses are subjoined 

 from an examination of nine specimens, which were taken 

 from regular strata in the great coal-field that lies around 

 Glasgow. * 



* It may be proper to notice, that, excepting in the second example, no 

 experiments were made for the purpose of determining the precise quan- 

 tity of water contained by the several specimens. 



VOL. VII. NO. II. OCT. 18S7- 



