UNCLE IN ENGLAND. 5 



It is evident from these facts, my uncle says, that 

 their origin must be more recent than those rocks 

 on which they repose; yet they are quite free from 

 all organic remains none, either animal or ve- 

 getable, having yet been found in any rock of this 

 class in England, nor, he believes, in any part of 

 the world. 



These circumstances have given rise to much 

 discussion as to the original formation of these 

 trap rocks, whether by fire or by water ; but 

 that is a subject on which my uncle will not yet 

 allow us to touch. Some species of this family 

 have the appearance of crystallization ; green- 

 stone trap, for instance, has large distinct crys- 

 tals of felspar ; in others, every trace of distinct 

 crystals vanishes^ and the whole assumes a dull 

 earthy appearance. 



The famous basaltic rocks, of which there are 

 such singular specimens in Scotland and Ireland, 

 belong to this family ; but I shall be able to tell 

 you much more about them in a few months, 

 my dear mamma, for my uncle says it will be 

 necessary for him to visit Ireland, and he pro- 

 poses to take us all with him to see the Giants' 

 Causeway. You will be surprised at this ; but 

 pray do not be alarmed ; I assure you there is 

 no danger now from the wild Irish. My uncle 

 has been there already, and from what he says, 

 I think some parts of that country must be very 



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