f yr ) 
Vitrioi,^llom or Nitre, thefaidEarth beingexpofed a fuf- 
ficient time^nto the Air, acquires frefft fupplies, and thac in 
fuch quantity,that many have concluded (which I can neither 
contradift nor confirm) thac in an hundred or fome few more 
years the Earth would yield more Salt than its whole bulk 
' amounted to in the beginning of the operation ; a great^if not 
thegreateft, portion whereof muft be derived from the Air. 
And it is particularly remarkable in Vitriol and Allom, that 
their Spirit being put into a Commotion or Fermentation by 
either heat or contrary-natur'dfpirits, the glaffes which con- 
tain them being well clofed, although large and ftrong,will be 
crackt or broken in pieces ; which feemsi:o proceed from the 
expanfion of fome of thofe prodigioufly aftive Springy par- 
ticles, wherewith the Air abounds, which together with the 
Aerial Salt were arrefted by the Vitriolifying principle, and 
fet at liberty by the tumukuating liquor, the changeofwhofe 
contexture might occafion their difmiffion, the unbending of 
their Springs, and the effefls which thereupon enfue. Bur, 
whether the Vitriolate Marcajites are only Magnets, to attrad 
and fpecificat the Aerial Salt and Spirit j or whether thefe are 
as well Aftive as Paflive, feparating, comminuting, and after 
combining with the Mineral particles, fo that the refult is 
difFerentfromwbateitherofthem were before fuch union, I" 
leave unto farther Enquiry ; FGr,though I could fay much on 
this occafion, yet I fliall defer it, until fome few more Experir 
ments have enabled me to make more perfed difcovery 
of a Truth, which is not.fo obvious as moft may. ima- 
gine. 
I fliall now proceed to demonftrate unto you the affinity 
between AllommdVitriol I mean, the Namra/^not common 
FaSf mem AWom; Sea-falt, Alcalies, and Urine being ufual- 
]y imployed in its produftion. l^ow,Vkml not only in E/^g- 
kndy but in feveral other parts of the world, is ordinarily 
found in the fame Vein, and fometimes in the fame parcel that 
yields the Allom ; which may by feveral methods be feparated 
from each other. The mineral of ^to, if mature, elixivia-^ 
ted yields its fait prefently ; if lefs mature, it requires previ- 
ous Calcination ; if very immature, it muft not only be burnt, 
but 
