Of XFO I^D^HI^E. 35 



- 29* A curious pattern I have of this kind, in a piece of wood 

 given me by M r Pomfret School-mafter of Woodfiock. (whofe care 

 in my enquiries I muft not forget) wherein nature has been fo 

 feafonably taken in her operation, that the method flie ufes is ea- 

 fily difcovered ; for being interrupted in the midft of her work^ 

 one may plainly fee how the ftony atoms have intruded themfelves, 

 as well at the center zs/uperficies, and fo equally too into all parts 

 alike, that 'tis hard to difcern in any part of it, whether ftonc 

 or wood obtain the better (hare. 



,30. Petrifications of this kind are always friable, and though 

 fomtimes they faintly fhew the grain, yet never, that I could fee, 

 keep the colour of the wood ; in the fire they are as incombufiible 

 as any other ftone, andlofe nothing of their extenfion, but their 

 colour for the moft part feems to alter toward white : in diftil- 

 led Vinegar they remain indiffoluble , though not without the 

 motion (as M r Hook" well obferves) that the fame fpirit has when 

 it corrodes Corals, yielding many little bubbles, which in all pro- 

 bability (as he fays) are nothing elfe but fmall parcels of Air dri- 

 ven out of its fubftance by that infinuating Menflruum, it ftill re- 

 taining the fame extenfion : but in aqua forth, the Sommerton 

 cruft was wholly diffolved into a white fubftance, not unlike the 

 white wa[h ufed by Plaislerers. All of them increafe the bulk of 

 the fubjeft on which they work ; and moft of them, as the inge- 

 nious M r Hook? alfo further notes, feem to have been nothing 

 more but rotten wood, before the petrification began. 



3 1 . But fome others I have fcen of a far nobler kind, that 

 fhew themfelves likely to be petrifications per minima, and per- 

 formed with a fteam fo fine, as permeates the very fchematifm and 

 texture of the body 5 that even to a Microfcope feems moft folid, 

 and muft in all likelyhood be as tenuiou* as the fubtileft effluviums 

 that come from a Magnet ; fome whereof are fo unlike rotten 

 wood, that they keep the colour and texture of heart of Oak, and 

 are fome of them fo hard that they cut Glafs : and with one of 

 them, that feems formerly to have been apiece of Ground-ajh, I 

 ftrook fire to light the candle whereby I write this. But I have 

 nothing more to fay of it here, becaufe I guefs the change not 

 to have been wrought by water; that therefore I offer not vio- 

 lence to the Chapter of Earths, by which I think this, and all 



Micograph- O&f. if. 



E 2 other 



