32 The Rev, D. Williams's Cliff Section of Lundy Islatid. 



depends upon a pre-provision of lime in the medium in which 

 they are destined to live, should originally have created it out 

 of nothing, very admirably sustains the unities of the fiction. 



He had learned in Devon and Cornwall, that the several 

 granite bosses there, pertained to and were inseparably con- 

 nected with certain well-defined divisions, of what he termed 

 the Ocrynian group. Those granites he regarded severally 

 as so many ancient submarine volcanic centres, consecutively 

 generated, and raised to their present positions by " elevation 

 crater movements," each one standing out now in lofty and 

 august relief above its mineral relations and dependences, the 

 tor-crowned type and head of its own volcanic department. 



Those inseparable associates and dependences on granite, 

 were syenites, porphyries, hypersthenes, serpentines, green- 

 stones, greenstone ash and tuff, clay schists, crystalline slates, 

 and co}-al built and chemically precipitated limestones. 



In every instance the author had met with, all the lime- 

 stones and calcareous rocks which had been invaded and acted 

 on by the vein-like processes of fusion, or by active heat, had 

 lost either the larger proportion or the whole of their lime ; 

 in other words, the lime and carbonic acid had been driven 

 off by heat. 



Bearing on this fact, the vast masses of travertine which have 

 been precipitated from water in subaerial volcanic districts, 

 must have been at the expense of some other rocks or pro- 

 ducts, from which it had been abstracted by it, a result no 

 doubt of the eager affinities which are known to subsist be- 

 tween lime and water. 



These simple and familiar principles he considered quite 

 adequate to explain the relative absence or low per-centage 

 of lime in granite, and in its many metamorphosed and dis- 

 guised relations, taking them as submarine volcanic products. 

 The lime, driven off by the reduction of calcareous rocks, or 

 availing itself of the freedom it acquired in the condition of 

 fluid lava, would readily part from its less attractive associates 

 to unite with an element of more powerful affinities, which 

 would serve as its vehicle of translation beyond the cincture 

 or radius of the deadly volcanic emanations and their "azoic 

 and protozoic " deposits, to remoter and more genial regions, 

 where it would minister to the requirements of multiplying 

 myriads of coral architects and other zoo])hytous, molluscous, 

 crustacean, and vertebrate creatures, which out of that con- 

 stant provision and supply of materials would in time con- 

 struct rock masses of such corresponding scale and dimensions, 

 as to contribute to and subserve the more final purpose of ter- 

 restrial restoration or repair. 



