Lough Neagh contains a great variety of fish. Besides salmon, a large kind of trout, bream, and perch, it contains the pollen, which is the same as the Terra of the lake of Geneva, and the ,rtoynia of Bala Lake in North Wales. Lough Erin, a small water in the county of Down, is re markable for producing pike, trout, and eels, of an enor mous size. Pikes of 26 lb. weight ; and yellow trouts, lit tle inferior in flavour to the char, of 12 lb. weight. The char is said to be found in the loughs in the mountainous part of the county of Waterford. The oysters taken near Carlingford are celebrated for the peculiar richness and delicacy of their flavour.
Ireland is said to rest on a bed of granite ; and this is highly probable, since granite is very conspicuous and abundant on its highest mountains. Of it the central moun tains in the county of \Vicklow are formed, and likewise that ridge which separates the counties of Wexford and Carlow. That portion of the county of Kilkenny, which lies between the Nore and the Barrow, abounds in granite of various shades, grey, red, and yellow ; there is a valu able quarry of it at Mount Loftus. In some parts of the county of Down it is met with in detached masses ; and in other parts it appears to compose the hills ; it also abounds in the neighbourhood of Dublin ; and is found emerging from beneath the basalt mountain of Sleeve•Gallen in the county of Derry. It is every where used for architectural purposes.
The following facts respecting the granite near Dublin may be interesting in a geological point of view. From the shore, on the south side of Dublin Bay, there passes, in a south-western direction, a broad body of granite, bound ed on its eastern and western sides by incumbent rocks of great variety. At Killarney, schistose rocks repose for a considerable extent on granite ; and the line of junction, which begins at the sea side, may be traced for some miles across the country. On the shore, it is traversed by nu merous veins, many of which are themselves composed of granite ; and, in some instances, two veins of this sub stance, differing from each other, and from the mass, in fineness, and in the proportion of their ingredients, are seen to intersect. The actual contact of granite with incumbent rocks, has been observed at several places in the counties of Dublin and NN'icklow. On the shore of Dublin Bay, not far from Blackrock, a mass of compact limestone is risible Nvithin a few fathoms of the granite ; but, in the intermedi ate space, the rock is concealed. On the western boundary of the granite rocks nearest to Dublin, rocks composed of trap occur ; and thence, to the south-west, along the bor ders of the counties of Wicklow and Kildare, there are various intermediate rocks between the granite and the limestone of the flat country to the westward.
Limestone is met with in general in great abundance in all the counties of Ireland, except Wexford, Wicklow, Tyrone, and Antrim. It has already been mentioned, in treating of the soils of Ireland, that the rivers Barrow, Lee, Bride, Kenmare, and Blackwater, form the boundary of the limestone districts in their respective courses. Of this mineral there are several kinds, both such as are interest ing to the geologist, and such as are useful in an economi cal point of view. The quarries in the immediate vicinity of Dublin afford many varieties of calcareous productions. The cxlp of Mr Kirwan is the prevailing rock. Brown spar is found in some quarries; and beds of magnesian limestone have been observed on the Dodder. The lime stones of Ireland are not less important in an economical point of view. Limestone of a fine white grain, lying in strata from four inches to two feet thick, and of which co lumns have been raised between nine and ten feet long, and from fifteen to eighteen itches in diameter, abounds at Ardbraccan, in Meath. This limestone receives a very high polish ; and, when long exposed to the air, assumes a greyish colour. Blue and white limestone are found in the county of Derry. Some of the former is little inferior to marble. But perhaps the most useful limestone for build ing is that found at Kilkenny. It is of various colours, white, reddish, and black. The last is of a remarkably fine texture, and susceptible of a high polish. All the limestone of Kilkenny contains marine shells of various species, as well as impressions of coraleries, &c. Marble, by no means of inferior quality, is met with in many parts of Ireland. The most beautiful is that of Kilkenny. The Black Quarry, which lies about half a mile to the south of the town of Kilkenny, affords a species of marble nearly equal in quality to that of Italy. The ground is black, varied with white marks, which assume a stronger tint when exposed to the air. About 50 tons annually are ex ported. Marble is also found in the counties of Cork, Ar magh, Down, Kerry, &c. Limestone, containing iron and manganese, is found in various parts of Kilkenny. A spe cies of whetstone, which, after being boiled in oil, is used by the country people for whetting razors, &c. is met with on the mountain of Mangertan. The mountain of Alta honey, in county Down, abounds in white calcareous spar, which is used for tombstones, window-stools, &c. In the Cave of Dunmore, in the county of Kilkenny, alabaster abounds in large masses.