v.] THE LIME IN THE MORTAE. 123 



the greater number of the beautiful and precious South 

 Sea Islands are only the remnants of a vast continent 

 or archipelago, which once stretched for thousands of 

 miles between Australia and South America, 



Now, applying the same theory to limestone beds, 

 which are, as you know, only fossil coral reefs, we 

 have a right to say, when we see in England, Scotland, 

 Ireland, limestones several thousand feet thick, that 

 while they were being laid down as coral reef, the sea- 

 bottom, and probably the neighbouring land, must 

 have been sinking to the amount of their thickness 

 to several thousand feet before that later sinking 

 which enabled several hundred feet of millstone grit to 

 be laid down on the top of the limestone. 



This millstone grit is a new and a very remarkable 

 element in our strange story. From Derby to North- 

 umberland it forms vast and lofty moors, capping, 

 as at Whernside and Penygent, the highest limestone 

 hills with its hard, rough, barren, and unfossiliferous 

 strata. Wherever it is found, it lies on the top of 

 the " mountain," or carboniferous limestone. Almost 

 everywhere, where coal is found in England, it lies on 

 the millstone grit. I speak roughly, for fear of con- 

 fusing my readers with details. The three deposits 

 pass more or less, in many places, into each other : 

 but always in the order of mountain limestone below, 

 millstone grit on it, and coal on that again. 



Now what does its presence prove ? What but 

 this ? That after the great coral reefs which spread 

 over Somersetshire and South Wales, around the pre- 

 sent estuary of the Severn, and those, once perhaps 

 joined to them, which spread from Derby to Berwick, 

 with a western branch through North-east Wales, 



