

ISLA. MINERALS. <257 



in the neighbourhood of Portaskeg, which belongs, 

 as must already have been apparent, to the primary 

 class of rocks. It has been wrought in five dif- 

 ferent places, but there are no means of discovering 

 whether these were distinct veins. It is indeed said 

 in the island, that there were no continuous veins, but 

 that the ore was found in independent masses : the 

 authority for this assertion is not however scientific. 

 There would be great facility in renewing the works, 

 as the bottoms are in a state of drainage by means 

 of the levels ; the position of the ground being favourable 

 to the discharge of water. 



Iron is found in various forms in different parts of 

 the island. In the white limestone of Lossit hill there 

 is a considerable bed of brown hematite interspersed with 

 minute crystals of oxidulous iron, of which some has 

 been sold and exported. This ore is sometimes mag- 

 netical, and it has been said to produce good iron. 

 It was already mentioned that oxidulous iron ore is here 

 found in quartz veins, and it occurs besides in many 

 other situations, chiefly in the clay slate ; but in quantities 

 far too small to render it an object of economical pursuit. 

 Bog iron ore may also be seen in several places under 

 the peat; the country abounding in chalybeate springs, 

 from which it appears to be a deposit. A sort of 

 siliceous iron stone is not unfrequent among the alluvial 

 beds ; being fragile, and apparently of very recent formation. 



Such were the minerals that came under my own 

 observation, but I was informed that common reniform 

 iron stone had been observed in some places. No 

 specimens of this ore were however produced, nor can 

 I understand whence it could have been derived, as 

 it is not a substance to be expected in any of the 

 rocks which have been described. The workmen in 

 the quarries further assert that they sometimes pick up 

 that variety which is characterized by the loose position 

 and mobility of a central nodule. It is further said, 



VOL. n. .s 



