[ IS* 1 
the fixed air, and by plunging a piece of red hoi 
glafs into it, raifed a copious and thick fume. This 
floated upon the furface of the fixed air like other 
fumes, and continued as long. 
Confidering the near affinity between water and 
fixed air, I concluded that if a quantity of water was 
placed near the yeaft of the fermenting liquor, it 
could not fail to imbibe that air, and thereby acquire 
the principal properties of Pyrmont, and other me- 
dicinal mineral waters. Accordingly, I found, that 
when the furface of the water was considerable, it 
always acquired the pleafant acidulous tafte that 
Pyrmont water has. The readied way of impreg- 
nating water with this virtue, in thefe circumlfances, 
is to take two veftels, and to keep pouring the water 
from one into the other, when they are both of them 
held as near the yeaft as poflible 3 for by this means 
a great quantity of furface is expofed to the air, 
and the furface is alfo continually changing. In this 
manner, I have fometimes, in the fpace of two' or 
three minutes, made a glafs of exceedingly pleafant 
fparkling water, which could hardly be diftinguifhed 
from very good Pyrmont. 
But the moft effectual way of impregnating water 
with fixed air is to put the veftels which contain the 
water into glafs jars, filled with the pureft fixed air, 
made by the folution of chalk in diluted oil of vitriol, 
{landing in quickfilver. In this manner I have, in 
about two days, made a quantity of water to imbibe 
more than an equal bulk of fixed air, fo that, ac- 
cording to Dr. Brownrigg’s experiments, it muft have 
been much ftronger than the beft imported Pyrmont ; 
for though he made his experiments at the fpring 
head. 
