The ^h[^tural Hiftory 
are all covered with ftone, and hang down the bank like fo many 
Ificles ; and the Earth it felf over which it glides, as 'twere foli- 
ated over with a cruft of ftone like the Mofco petrofo of Ferrante 
Irnperato^, Which brings me to a clofer confideration of waters, 
as they are eminently endued with any peculiar qualities, of Fe- 
trification^ Sahnefs^ or Medicinal ufe ; of which in their order as 
briefly as may be. 
23. Of Petrifying waters^ though I doubt not but their kinds 
are as various,as the effefts they produce ; and the effefts again, as 
the fubjedls they work on ; yet I am inclined to believe that they 
all agree thus far, that they proceed in the main from the fame 
ftock and linage, and are all more or lefs of the kindred of Salts^ 
which fublimed and ratified in the bowels of the Earth into an 
invifible fteam, are received by the waters as their moft agreeable 
vehicle^ and brought hither to us at the riling of Springs^ as in- 
vifibly as the particles of filver or gold, when each is dilTolved 
in its proper menflruum : where meeting perchance with an am- 
bient ^ir, much colder and chilling than any underground, in 
all likely hood zrc -preciptatecl^ and thrown down on fuch fub-J 
jefts, as they cafually find at the place of their ex/>, which they 
prefently cloath with a cruft of ftone ; or elfe (where precifita- 
tion or cohefion will not fuftice) they pafs with the waters through 
t]\Q pores the fubjedtsj and are left behind in them )uft as in a 
filter, 
24. The reafon of which difference may probably be, that 
fome of thefe petrifying fteams or atoms^ may be grofs and more 
bulky than fome others are, and cannot be held up in the watry 
vehicle^ without fuch a heat as they have under ground, but fall, 
and by reafon of their bignefs, do not penetrate^ but adhere to 
their fubjefts • whereas others that are fine, more minute and fub- 
tile, are eafily fupported in a volatile condition, and pafs with 
the waters into the clofeft textures, 
25. If any body doubt whether ftones, and petrifications^ 
arife from Salts^ let him but confuk the Chymifts^ and afk, Whe- 
ther they find not all /WKrfl/e^/Bodies,fuch as ftones, boncs,(liclls, 
and the like, moft highly fated with the faline principle ? Some 
mixture of Earth and Sulphur 'tis true there is in them, which 
give the opacity that moft ftones have ; from which, according as 
^Deir Hi[i. Natural. lil>.2-].caf.Z- 
they 
