302 The ViTRict 



refolved in the bowels of the earth, do at the day, 

 or above the earth, remarkably change or vitrio- 

 life -, and that without any thing foreign, befides 

 the accefs of the air, from which, under the 

 earth, they are atleaftmore fcreened. Now, here 

 it is worth remarking, that in many forts of pyri- 

 tes, the punfium fallens of this new production acts 

 from within the pyrites outwards, the vitriol not 

 fettling from without, but (Iriking out from with- 

 in ; as fufflciently appears, not only from pyrites- 

 globes, which, in their falling to pieces, generally 

 from their middle emit genuine native vitriol, but 

 from other angular pieces of pyrites, broke off 

 from veins, and which on the fide, where they are 

 thus broke off, ever turn vitriolic. 



Two queftions with refpecl: to the pyrites- 

 globes here offer themfelves to our confideration, 

 (i.) How the air can break into fuch clofe com- 

 pact bodies. 



(2.) Why it does not rather eat into their cir- 

 cumference, and thus operate from without irr- 

 wards. As to the firft, the round pyrites in gene- 

 ral, or fuch as vitriolife in that manner, are in- 

 ternally, and in their inmoft parts, not fo clofe and 

 compact as in their external circumference ; nay, 

 have a fmall, an almoft unobfervable cavity -, fur- 

 ther, that this fort, as was obferved above, con- 

 fids of a number of cones or pyramids, and not 

 only upon a fpontaneous refolution, but upon the 

 application of an external force, whilft (till frefh, 

 falls to pieces of fuch a conical form. Now, as it is at 

 thefe radii or cones, iffuing out from the centre, 

 we ever obferve the refolution of thefe cones to 

 happen, they are, doubtlefs, traces of fmall ten- 

 der fiffures, or figns of the cohefion not having 

 hitherto become fo clofe, as thefe cones do not fo 



readily 



