Kinahan — On Granite and Metamorphic Rocks. 179 



Glass. — The granulyte (veins of segregation) in the Killiney 

 and other Dublin granites, when fine-grained, highly felspathic, 

 and nearly micales, as also the nearly similar elvans in the mar- 

 ginal micalyte, have been pronounced suitable for use in the 

 manufacture of ornamental and bottle glasses. 



Similar elvans, as hereafter mentioned, occur in Cos. Kildare, 

 Oarlow, and Kilkenny, west of the granite range ; while associated 

 with the laccolites at Little Eock, Arklow, further north at Lewis 

 Ville, Kilbride, as also in Croaghan Kinshella, and neighbouring 

 hills, there are fine elvans similar to, if not identical with, the 

 Devonshire granulyte now (1888) imported by the glass-bottle 

 makers of Bingsend, Dublin. 



For the convenience of description, Ireland may be divided 

 into four Territories, namely — (1) the Leinsier, or south-east; 

 (2) the Munsfer, or south-west ; (3) the north-west and north ; 

 and (4) the north-east [excluding Antrim, put, for convenience, 

 into (3)]. These limits have been regulated as much as possible 

 with reference to the affinity of the Exotic rocks in each of them 

 to one another. The above division agrees in the main with this 

 affinity ; except in regard to the last two divisions, the later rocks 

 occurring in both. This, however, is so partial that it does not 

 disturb the general arrangement. 



In this, as in my earlier papers on the Economic Geology of Ire- 

 land, I am indebted for much information to previous writers, and 

 to numerous correspondents, to whom again I return sincere 

 thanks ; as often as possible the names of the local contributors 

 are given in connexion with their information, thus authenticating 

 the various statements. 



LEINSTEE, OE SOUTH-EAST IEELAND. 



Chronological Account. 



[Queen's Co., King's Co., Kildare, Dublin, Wicklow, Carlow, Kilkenny, 

 Wexford, Waterford.] 



As indicated in the Table {ante, page 170), the granitic and allied 

 rocks in south-east Ireland are of different ages, and are varied in 

 character and composition. Prior to giving the Territorial 

 Descriptions, it seems advisable to treat of the rocks chronologi- 

 cally, more fully than could be done in the Table. 



