Of 0XF0%T>-SH11{E. 6^ 
rals^ latent underneath them in the bovv^els of the earth, my 
conjedure thereby is not made the lefs valid. 
36. With the Pyrites cinereus^ or Coper a6 ft one ^ not Unlikely 
there may alfo be fonie mixture of Arfenic^ which advances it3 
malignity to that deadly ftrength, that no man may approach un^ 
der pain of death: But that for the future, the infenfible inva- 
fions of this fecret enemy may for ever be avoided ; let all workr 
men^ and fuch as upon any account whatever have occafion to dig 
or go down in thefe wells, firft throw down into them a peck of 
good Lime^ which flaking in the water, and fuming out at the 
top, willfo effeftually difpel all fuch poifonous vapors, that they 
may fafely go down, and ftay fome time unhurt. 
37. From thefe mifchievous ones of Vitriol znd Arfenic^ I 
proceed to fome other more innocent falts-, before promifed more 
fully to be handled here, with which fome earths being peculiar- 
ly qualified, are accordingly difpofed.toj^?e/riyfe bodies. How all 
'petrifications ^ltc performed by faits^ and petrifications per minima^ 
by their fubtileft fteams, I fuppofe has already fufficiently been 
fl^iewn, as alfo how^ waters moil probably effeO: them : It remains 
only therefore now to be proved, that earibs as well as waters, do 
aiford fuch fteams as permeate alfo the moft folid texture, 
38. To which purpofe I met with a curious inftance in the 
Fields between Clifton and Nuneham-Courtney^ of aftone thai: 
reprefents a found piece of Afli, cut both parallel and tranfverfly 
to the pores, and retaining the grain and colour fo well and live- 
ly, that no body at fight believes it to be other than a firm and fo« 
lid piece of wood ; and yet this was taken out of grounds there- 
about, as far from water as one need to wifli. In (liort, the ver- 
fion feemsfo very perfed, its fubjeS: appearing to have been ve- 
ry found and free from rottenncfs, that either we muft own fuch 
petrifications i\s this ^ to be truly fuch, and totutn per totum^ or elfe 
allow that ftones may grow in grain and colour exadly like 
wood. 
3 9 . But that the latter of thefe may not fo far take place (thoug h 
the poffibility of the thing muft not be denyed) as to exclude 
a poffibility of its being fomtimes otherwife ; I take leave to in- 
ftance in another petrification made alfo by an earthy and not by 
' water ^ thatfeems to carry a neceffity with it, of its fubje£ls once 
being folid wood: for befide, that it ftiews the clofe grain of Oah^^ 
and 
