268 THEORY of the EARTH. 



a regulated procefs, determined by the degree of fufion, and 

 the circumflances of condenfation or refrigeration. In refpect 

 of thefe, the mineral veins now to be examined are anomalous. 

 They are ; but we know not why or how. We fee the effect ; 

 but, in that effect, we do not fee the caufe. We can fay, nega- 

 tively, that the caufe of mineral veins is not that by which the 

 veins and fiffures of confolidated ftrata have been formed ; con- 

 fequently, that it is not the meafured contraction and regulated 

 condenfation of the confolidated land which has formed thofe 

 general mineral veins ; however, veins, fimilar in many refpects, 

 have been formed by the co-operation of this caufe. 



HAVING thus taken a view of the evident diftinction between 

 the veins or contractions that are particular to the confolidated 

 body in which they are found, and thofe more general veins 

 which are not limited to that caufe, we may now confider what 

 is general in the fubject, or what is univerfal in thefe effects of 

 which we wifh to invefligate the caxife. 



THE event of higheft generalization or univerfality, in the 

 form of thofe mineral veins, is fracture and diflocation. It is 

 not, like that of the veins of ftrata, fimple feparation and mea- 

 fured contraction j it is violent fracture and unlimited difloca- 

 tion. In the one cafe, the forming caufe is in the body which is 

 feparated ; for, after the body had been actuated by heat, it is 

 by the reaction of the proper matter of the body, that the 

 chafm which conftitutes the vein is formed. In the other cafe, 

 again, the caufe is extrinfic in relation to the body in which the 

 chafm is formed. There has been the moft violent fracture and 

 divulfion ; but the caufe is ftill to feek ; and it appears not 

 in the vein ; for it is not every fracture and diflocation of the 

 folid body of our earth, in which minerals, or the proper fub- 

 ftances of mineral veins, are found. 



WE are now examining matter of fact, real effects, from 

 whence we would inveftigate the nature of certain events which 

 do not now appear. Of thefe, two kinds occur ; one which has 



acted 



