80 The Production and Generation 



which orey and metallic particles are to take their 

 rife : for, this itone confifts of pure fand- grains, 

 which are fo many fmall flints, and, confequently, 

 the denfeft corpufcles ; and like fo many hardened, 

 indurated matrixes, where the effete materials 

 are, even by the ftrongeft influx, with difficulty 

 brought to motion and conception. Yet here 

 fome might confider, as oppofite to this, the com- 

 monly flinty and quartzy, nay, horn-ftony rock 

 of the felvages, which, in veins, form the cafe for 

 the ore. But, not to mention that objects lying 

 near are not always to be fuppofed derivable from 

 each other, tho' they may fuccefllvely, or even 

 limultaneoufly, happen to exifl •, the principal re- 

 flexion and query here may be, whether fuch 

 quartzy and horn-ftoney rock was already become 

 fuch a denfe and clofe body, when the ore began 

 firft to be lodged there ? or whether it was- not of 

 a moifter, fofter, and a more receptible texture, 

 wherein the mineralifing weatherings or damps, 

 might find lodgement, incorporate itfelf, and thus 

 the tender veiTels of the matrix, namely, the ten- 

 der felvage^ emit fome material efflux for the pro- 

 duction of the ore ? The firft opinion fails, for 

 this reafon \ as it muft be allowed, that this ftub- 

 bornnefs in the earth was not original, but adven- 

 titious ; and that fomething flinty, quartzy, fandy, 

 floney, glafs-yieldy, or, in a word, Becher's firft 

 earth, might not exift in metals. 



And in thofe productions of the pyrites^ for 

 which the deluge has laid the foundation, fome- 

 thing peculiar is flill to be obferved: namely, 

 that pyrites is even found weathered on bodies 

 at a great remove from the mineral kingdom, 

 and unadapted for it, as wood ; of which I have 

 both ken and read inflances. M. Lichtwer of 

 Drefden, Infpector of his Majefty's cabinet of mi- 

 nerals, has a fmall piece of wood, on which a glit- 

 tery, 



