i8 94 .] 



THE BRITISH NATURALIST. 



189 



contradistinction to that other process of plundering existing continents 

 to furnish future lands out of the re-assorted filchings ? Permanence is 

 no part of nature's scheme — indeed, it is what she most abhors — and all 

 matter is in a state of constant flux and reflux of integration and dis- 

 integration, however various may be the rate of change. The facility 

 with which secretion leads to accretion is the intimate cause of the want 

 of durability of the product. The same property of its atoms that led 

 up to the building of the limestone rock is the most potent agent in its 

 decay, and the rainfall, which is made acid by absorption of carbonic 

 acid or by vegetable decomposition is for ever taking back the lime to 

 the state in which the primitive corallines discovered and appropriated it. 



The solution of strata of salt is a practical fact as to which no 

 inhabitant of Northwich feels any doubt. To me the carboniferous 

 limestone presents very similar phenomena of rapid removal. At 

 Killarney, even my short experience has disclosed scaling of cliffs and 

 falls of large pieces into the water beneath, whilst arched portions of 

 worn rock, which are exposed to the wearing effect of the attraction 

 of gravitation — such as the O'Donoghue's Horse — exhibit a clear annual 

 loss. Old boatmen, whose knowledge of the district extends backwards 

 for fifty years, are ever ready to talk of similar changes. 



Hence I see no improbability, but almost a certainty, in the belief 

 that the limestone at one time stretched in a continuous sheet from the 

 Killarney Lakes to the Kenmare River. The space of time is so 

 enormous that every trace of the superincumbent stratum may easily 

 have been washed or dissolved away from the surface of the Old Red, 

 rising slowly to greater elevation than at present, and the only traces 

 that would be left would be at the base of the mountains or in such 

 protected hollows or in such fragmentary detachments as we now see. 

 What is still extant of the Carb. Limestone is principally to be studied 

 on the eastern ends of the middle and lower lakes. These two stretches 

 of water are separated by a promontory which tapers to a point — at 

 Brickeen — and by coasting along this promontory from W. to E. you 

 have displayed an admirable section of the strata which here compose 

 the Carb. Limestone. First you have a yellow sandstone — a narrow 

 band of plunder from the real Old Red ; 2nd, a shaly stratum of corn- 

 stone, a mixture of lime and sand ; 3rd, a shaly stratum of alternate 

 layers of lime and sand, and as the more soluble element is in most 

 cases eliminated where exposed to the water, the rock is called the 

 " honeycomb " ; 4th, a compact rock, which in places furnishes building 

 stone of very superior quality, but, unfortunately, the quantity is very 

 limited, and more frequently runs into shales or plates, which when 

 tumbled about in disorderly heaps has suggested the notion of the 

 O'Donoghue's Library ; and 5th, a granular amorphous limestone which 

 always reminded me of ancient chalk. This stratum is much thicker 



