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Is other trads where the fame earths occurred, but not in the 

 proportions fitted to produce granitic ingredients, other mafles of 

 the filiceous genus, as fiiiccous fliiftus, filiceous porphyries, jafpers, 

 &c. were formed by a lefs perfed: and confufed cryftalhzation. 



In various places argillites, hornblende flates, ferpcntines and 

 other primaeval ftones of various denominations muft have arifen 

 according to the predominant proportion of their ingredients by 

 a more or lefs perfed or partial cryftallization. 



Metallic fubftances (all of which I fuppofe to have originally 

 exifted in their complete metallic ftate) and particularly iron, of 

 all others the molt copious, muft in fundry inftances have met and 

 combined with fulphur, the fubftance to which all and particu- 

 larly iron has the greateft affinity, and thus pyritous fubftances 

 and fulphurated ores originated. Petrol, fpecifically lighter in- 

 deed than water, but involved in the chaotic fluid, meeting fulphur 

 to which it has an affinity, with it formed a liquid fpecifically 

 heavier, which gradually involved and was abforbed by carbonic 

 particles which were thus collcded and precipitated. 



It is a facfl at prefent well eftablifhed, that in the aO. of cryf- 

 tallization a very confiderable degree of heat is generated. Judg- 

 ing then by analogy, how great then muft have been the heat 

 produced by the cryftallization of fuch immenfe quantities of 

 ftony maffes as took place at this period, the immediate effed 



of 



