MicroGRAPHihe 109 
though perhaps many of thofe {mall Bubbiles inight proéeed trom fomé 
fnall parcels of Air which were driven out of the pores of this petrify'd 
fubftance by the infinuating ae menfirunm, r tusthh sabrics 
-Sixthly, in its rigidwefi and friabilrty, being not at all flexible but 
brittle like ‘a Flint, infomuch that I could with one knock of aHamme# 
break off a piece of it, and with a few more, teduce that into a pretty 
fine powder. — 20s Drak ris é9-ersdio 
Seventhly, it feem’d alfo very differing from Wood to the tonch, feels 
ingmore cold then Wood ufually does, and much like other clofe {tones 
and Minerals. : Lottie be 
» The Reafons of all which Phewomena feemtobe, | 
. That this petrify'd Wood having lain in fome place where it was well 
foak’d with petrifyéxg water (that is. fuch a water «as is well smpreghated 
with ftony and earthy patticles) did by degrees feparate,cither by {trains 
ing and filtration, or perhaps,by precipitation, aire ot coagulation,abun- 
dance of ftony particles from the permeating water, which ftony par- 
ticles,being by means ofthe fluid vehicle convey 'd,nbt onely intd the Ags 
crofcopical pores, and fo perfectly ftoping them up, but alfo into the pores 
or interftitia;which may, pethaps, be even in the texture or Schématifine 
of that part of the Wood,which, through the Asicrofcope,appears moft fo+ 
lid, do thereby {0 augment the weight of the Wood, as to makeit above 
three times heavier then water, and perhaps, fix ‘times as heavie as it wag 
when Wood; 2H lorqit 9735 a Ano} ab be 
the fire carinot eafily make them flie away.but the action of thefire upoa 
them isonely able to Char thofe parts, asit were; like a pi¢ce of Wood,if 
‘eatak beuwh colour: after it hadi been ere 3 pee ot 
_ By this zntrafion of the petrifying particles, this fubftance alfo becomes 
iurd and ‘friable; fot the fmaller pores of the Wood. being perfectly 
wedg'd, and ftuft up with thofe ftony particles the ‘fall. parts of the 
x have no places or pores into which they may flide upon’ 
and conegueny little: 6¢ no flexion of yielding avall can be caus’d in 
fats: fiend: to sonciidit b:woloe-ti.9L 10 3 3 
+, The remaining particles lixewife of the Wood atong the flony pir 
ticles; may keep them from cracking’ and fying bed pe tapeee 
as theypare very apt rodoin aFlinys 
“Not is Wood the oniely-fubftance that may by this kind of taste 
bout Keinfham, which ties within four ot five miles of Briffol, which are 
commonly call'd Serpentinc-ftones. Exarni- 
