254 THE ORY of the EAR <TH. 



ifle of Wight directly weft into Dorfetfhire, and goes by Corf- 

 caftle towards Dorchefter, perhaps beyond that place. The fea 

 has broke throtigh this ridge at the weft end of the ifle of 

 Wight, where columns of the indurated chalk remain, called 

 the needles ; the fame appearance being found upon the oppo- 

 fite more in Dorfetfhire. 



IN this field of chalk, we find every gradation of that foft 

 earthy fubftance to the inoft confolidated body of this indurated 

 ridge, which is not folid marble, but which has loft its chalky 

 property, and has acquired a kind of ftony hardnefs. 



WE want only further to fee this cretaceous fubftance in its 

 moft indurated and confolidated ftate ; and this we have in the 

 north of Ireland, not far from the Giants Caufeway. I have 

 examined cargoes of this limeftone brought to the weft of Scot- 

 land, and find the moft perfect evidence of this -body having 

 been once a mafs of chalk, which is now a folid marble. 



THUS, if it is by means of fufion that the ftrata of the earth 

 have been, in many places, confolidated, we muft conclude, 

 that all the degrees of confolidation, which are indefinite, have 

 been brought about by the fame means. 



Now, that all the ftrata of the mineral regions, which are 

 thofe only now examined, have been confolidated in fome de- 

 gree, is a fact for which no proof can be offered here, but muft 

 be fubmitted to experience and enquiry ; fo far, however, as 

 they fhall be confidered as confolidated in any degree, which 

 they certainly are in general, we have inveftigated the means 

 which had been employed in that mineral operation. 



WE have now confidered the concretions of particular bo- 

 dies, and the general confolidation of ftrata ; but it may be 

 alleged, that there is a great part of the folid mafs of this 

 earth not properly comprehended among thofe bodies which 

 have been thus proved to be confolidated by means of fufion. 

 The body here alluded to is granite ; a mafs which is not ge- 

 nerally ftratified, and which, being a body perfectly folid, and 



forming 



