276 Dr. FiTTON o« the Geology of the 



This fossil seems to have been first taken notice of under the 

 name of Witrficher (cubic) Feldspath by Karsten, who took his de- 

 scription from specimens in the Leskean cabinet now in Dublin f 

 (No. 907 b^ &c.) ; and from a comparison of these with the speci- 

 mens from Douce, the identity of Karsten's fossil, with Andalusite is 

 ascertained. I have not found however, that his claim to the first 

 detciflion of it has been mentioned by subsequent writers : although 

 his opinion with respect to its affinity to felspar, accords with that 

 which Haiiy is disposed to adopt. Tableau comparatif, &c. p. 217. 



To this species is also to be referred a mineral which occurs in 

 great abundance at Killiney in the County of Dublin, first observed 

 there by Dr. Blake, and for some time considered as belonging to a 

 non-descript species. It is most remarkable on the shore at the 

 southern extremity of the cliff under the obelisk hill, where it 

 appears thickly on the surface of beds of mica slate ; and it seems to 

 abound also imbedded in the substance of that rock, although less 

 distinctly visible until it has been exposed to decomposition, being 

 less affected by exposure than the rock in which it is contained. 



The Atidahisite^ when thus brought to view, appears generally in 

 slender prismatic crystalline pieces rounded at the angles, seldom 

 sharp, promiscuously aggregated, sometimes in a stellular form, and 

 of a greyish-black colour, remarkably contrasted with the lustre and 

 light colour of the micaceous substance in which they appear. But 

 in fresher pieces, the form, colour, cleavage, and other characters of 

 this mineral are distinct ; and I have observed an approach to the 

 peculiar appearances which it presents at this place, in some Spanish 

 specimens, where the crystalUne shoots had assumed a scapiform 

 arrangement. 



* Journal de Physique, xxxiv, p. 453. 1789. 

 + Bergman's Journal, vol. ii. p. 809. ann. 1788i 



