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not, hov/ev6r, conclude, till after repeated trials, that 
air does not fpontaneoudy feparate from the Pouhon 
water, in inch manner, and in fo fhort a time, as it 
is faid to feparate from the Dunfe, and Scarborough 
waters ; and that, when excluded from the common 
air, it will, for feveral days, bear the greateft heats of 
the fummer, ufually found in the ihade, at Spa, 
without parting with any of the air, or other princi- 
ples of which it is compofed. It is, however, mani- 
feft, that, by the heat applied in the above experi- 
ments, the Pouhon water was difpofed more readily 
to part with its air, or fome other elaftic fubflance, 
than it is when taken cool from the fpring : feeing 
that, when poured into a glafs, after it had been thus 
heated, it fparkled more than when frefh drawn from 
the fountain, and flew with more violence when 
fliaken in a bottle. 
We may alfo hence learn, that when bottles filled 
with the aciduhe are broken, in hot, fultry weather, 
accompanied with thunder, as Hoffman and others 
have obferved them, this accident muff rather pro- 
ceed from other caufes, than from the expanfion of 
their fubtile mineral fpirit, to which it is ufually attri- 
buted. That flalks filled with the Pouhon waters, 
are liable to fuch accidents w^hen unfkilfully clofed 
up, thofe, who fill them for exportation, have learned 
from experience. To prevent which, they fuffer the 
flafks, after they are filled, to remain feveral hours 
in a warm air before they cork them up. And I 
found, that one of thofe flafks being filled to the neck, 
at tlie Pouhon fpring, when Fahrenheit’s thermometer 
flood therein at 53 degrees, the water had arifen 
near three quarters of an inch in the flender neCk of 
the 
