204 CARBONIFEROUS. 



lime and magnesia, as well as argillaceous matter. They are worked principally 

 in Staffordshire, Shropshire, Yorkshire, Derbyshire, and in North and South 

 Wales. In tlie lower beds of the Coal-measures near Bradford, iron-pyrites has 

 been worked for the manufacture of sulphuric acid and sulphate of iron. 



Veins of Galena have been met with and worked in the Lower Coal-measures at 

 Whaley in Cheshire, and near Chapel-en-le-Frith. 



In the South Wales Coal-field, near Merthyr Tydfil, Hatchettine, or mineral 

 tallow, a hydro-carbon, is found in crevices of the clay-ironstone. Petroleum 

 springs have been met with in the Coal-measures near Broseley ; one called the 

 ' Burning Well ' existed about a centuiy ago. 



The Coal-measures form generally an unproductive soil ; but there are many 

 exceptions. The fine deep soil in which the people of Pomfret (Pontefract) grow 

 the liquorice-root to manufacture the "Pomfret Cakes," for which, among other 

 things, their town is famous, seems to be largely composed of the debris of the 

 Pontefract rock. ^ 



1 J. W. Kirkby, Q. J. xvii. 296. 



