In the Pyrites; 243 



be examined into and cleared up. But fliould it at 

 length appear to be a thing impofiible to enrich ores 

 and ennoble metals, this ufe at lead we may reap 

 from it ; viz. to learn not to throw away our labour 

 and time to no purpoie : on the other hand, fliould 

 we find fome degree of melioration attainable ; 

 this would not only encourage us for the prefent, 

 but be an incentive to us for the future to proceed 

 further. 



R 2 



CHAP. 



