in the Pyrites, 7 14$ 



Fourthly, from the ftructure or texture of the 

 pyrites, particularly the round fort, we fee it is be- 

 come what it is, through length of time, and by 

 means of coclion. The round fort is either tefta- 

 ceous or radiated, and by both ways of ftructure, 

 it exhibits fuch proofs of its origination, as are not 

 to be fought for from an external accumulation, but 

 from an internal conceding, fermenting, tranf- 

 muting elaboration : I fay, from the origination, 

 or formation of pyrites ; (and this I mean not of the 

 configuration or external form, but of the internal 

 efience and mixtion of the pyrites \) for, indeed, an 

 accumulation, not of matters actually pyrity, but of 

 matters adapted to fuch productions, muft both 

 be granted, and muft happen. Yet in clayey, 

 loamy, fhivery, marly beds, where pyrites is pe- 

 culiarly found in kidneys, fo large an accumulation 

 of matters, derived from other quarters, is not fo 

 much to be expected, nor is it neceffary (as there 

 the fubjacent fine earth, at leaft the iron portion, 

 contributing to the formation of the pyrites, is al- 

 ready proximately prepared for it •, which, to its 

 concentration, collection, and mineralifation, to- 

 gether with fome acid, or even fulphureous damps, 

 only wants fome degree of coction) as in thofe py- 

 rita rather, that lay upon drufe ; where nothing 

 earthy is obfervablej from which, as from a fub- 

 tratum, fo much metallic matter, as is to be found 

 in pyrites, could have been generated. 



Upon the whole, the fulphur in the pyrites fir ft 

 truly becomes what it is, and was not before for- 

 mally therein -, in the fame manner as other fixed 

 pyrites -earths, which, (previous to the pyritifica- 

 lion, were crude, though not fo very foreign to 



L 2 gh& 



