Phenomena of Granite Veins. 



501 



(47) Granite Veins in Micaceous Limestone Colrain. 



(48) Granite Vein in Micaceous 

 Limestone ; Colrain. 



I shall not in this place deduce any general theoretical inferences 

 from the facts respecting granite veins that have now been detailed. 

 In the sequel.however, I miy refer to them again,so far as they have 

 a bearing upon theory. 



Mineral Contents. 



In every part of the world granite is the repository of very many 

 of the most perfectly crystalized minerals : an evidence that its ma- 

 terials must once have been most thoroughly fluid, either by water 

 or heat. The number of mineral species in the granite of Massachu- 

 setts is not quite as numerous as in one or two other rocks : yet it con- 

 tains several of the most interesting minerals in the State. 



Sulphate of baryta is extremely abundant in it; though the most 



