312 



ILLUSTRATIONS OF THE 



• 



v^ins, that thefe veins 



though, to 



are formed by infiltra 



gi 



any probab 



to this 



fuppofition, it would be neceflary to fhew, that 



nite : 



able to dilTolve the ingred 



of 



d 



even if 



gra 



Id be done, the di 



redion which the veins have, in many inftances 

 rifing up from the granite, is a proof, as remark 

 ed § 82,, that they cannot 



filt 



be the effed of 



^ Another objed 

 namely, that the 



h 



been th 



f 



veins here referred to 



out, 

 are 



true granite, according to the definition 

 which mineralogifts have given of that fubftance. 

 The force of a fad, however, is not to be leflen- 

 ed by a change of names, or the ufe of arbitrary 



definit 



The gen 



faa 



flitul 

 with 

 The 



flunc 



fs, and the vein proceeding from 



that the gra 



any line of fep 



d uninterrupted body 



I rat ion betw 

 geological argument turns on th 



n them 

 circum' 



and 



no m 



rock be a fyenite, a granitelle, or a r 



The phenomenon fpeaks the fame language, and 



hether the 

 granite 



leads to the fa 



conclufi 



hatever be the 



technical terms the mineralogift employs in de 

 fcribing it. 



279. It muft, however, be admitted, that i 



difference of charadl 



J 



ften to be obferved 



between the granite m^fs and the veins proceed 



■<a 



m 



