f 
274 APPENDIX. 
ufcd large or fmall Qiiantities of this Air, 
with either Rain or common Water, frcfli or 
faked, unboiled or boiled, to clear it of its la- 
tent Air. 
y. Neither, as was obferved in the foregoing 
Experiment, will all the latent Air which is by 
Heat raifed out of feveral Waters, be reforb- 
ed again, or lofe its Elafticity till after feveral 
Weeks, as was the Cafe of the Airs from the 
Ehfham and ASton Waters. But as to the 
Pjrmont^ Spa^ivand Tunbridge Waters, whence 
a greater Plenty of this elaftic Matter is raiP* 
ed by Heat, it docs not continue fo perma- 
nently elaftic ; which maybe the Reafon w^hy 
feveral of thefe mineral Waters are obferved to 
grow vapid and lofe their medicinal Spirit: 
in {landing fome time, tho* well corked up in 
Bottles, and even tho' put into a Florence Flask 
which was hermetically fealed, as I was told 
by the late Dr. James Keill who cried the 
Experiment on a mineral Water near Nor- 
thampton : So that thefe Waters may be thus 
deprived of what is called their Spirit, not 
only by its hying away, as it will foon do in 
open VclTels, or when heated; but alfoby its 
being reduced from an elaflic fpirituous to a 
fixed State in the Water. 
We 
