446 



[Proc. B.N.F.C. 



rank of an exact science. Lime forms other compounds as well as 

 Carbonate of Lime, each having its own special form of crystal, 

 such as Phosphate of Lime, Sulphate of Lime, Fluoride of Lime, 

 Thomsonite, Aragonite, &c. Limestone yields readily to chemical 

 action, and is thereby removed and re-crystallised under various 

 conditions, even in the hollow spaces of basaltic rocks. 



On the north shore of Lough Neagh, at Cranfield, there is a 

 holy well reputed for having the power of curing sore eyes. The 

 well occurs in the fissure of a basaltic rock below some overhanging 

 trees. Some veins of carbonate of lime, like candied sugar, occur 

 in the rock, so that when the well is cleaned out crystals of the 

 lime are found in the bottom of the well. They are collected and 

 valued as charms for the benefit of defective eyesight. 



In many places in County Antrim the effect of surface- 

 water carrying lime in suspension may be seen by the deposit left 

 encrusting the surface after evaporation. At the calcareous wells 

 of Matlock and Knaresborough this process is employed to manu- 

 facture petrifactions for visitors, such as baskets and birds' nests 

 as the example on the table. In many limestone districts the 

 dissolving power of surface-water has been employed by Nature to 

 excavate great caverns beneath the surface, while the chambers 

 thus formed are fantastically decorated by the same means, pro- 

 ducing strange architectural effects and combinations of beauty 

 and grandeur of surpassing interest. In Antrim, Donegal, Fer- 

 managh, Galway and other counties there are examples of this 

 kind, but perhaps the most extensive and elaborately decorated 

 series of natural caves in Ireland are those of Mitchelstown, on the 

 borders of Tipperary and Cork. They cover an area of 24,000 

 feet, including passages up to 200 feet long, and chambers 100 

 feet in diameter and 35 feet high, richly decorated with drapery, 

 and columns of the purest crystalline marble. 



The caverns of Europe supply the earliest evidence of Prim- 

 itive Man, and in them are associated a long succession of extinct 

 wild animals, whose remains are carefully deposited in the order of 



