Kin ah an — On Irish Metal Mining. 



231 



SULPHUR AND GOSSANS. 



[Sulphur occurs native, as concretions in the" Carboniferous Limestone, in the counties of 

 Galway, Mayo, and Wexford ; but the principal Irish ore from which it is obtained 

 is the sulphide of iron {pyrite) : but in the Co. Galway pyrrhotite, or magnetic 

 P3 r rites, is found, and has also been mine I. These ores usually contain some units 

 of copper {chalcopyrite) : the more of the latter present, the greater the value of the 

 ore ; as after the sulphur is obtained copper can be abstracted from the ash. Some 

 of the pyrrhotites are nickeliferous. Some conspicuous gossans and strong chalybeate 

 springs will be included in this list ; in some cases they may only indicate the 

 presence of iron, yet in many cases they come from pyrite veins. The localities 

 where the quantity of pyrite is small and valueless are not given.] 



