[ 2 35 ] 
Tranf. Vol. LVI. p. 157. by which, though, he 
fays, he was not able to get any inflammable air 
from copper, by means of fpirit of fait, he got a 
much more remarkable kind of air, viz. one that 
loft its elafticity by coming into contadt with water, 
I was exceedingly deflrous of making myfelf ac- 
quainted with it. On this account, I began with 
making the experiment in quickfilver, which I never 
failed to do in any cafe in which I fufpe&ed that air 
might either be abforbed by water, or be in any other 
manner affedted by it; and by this means I prefently 
got a much more diftindt idea of the nature and 
effedts of this curious folution. 
Having put fome copper filings into a finall phial, 
with a quantity of fpirit of fait; and making the air, 
which was generated in great plenty, on the appli- 
cation of heat, afcend into a tall glafs wflel full of 
quickfilver, and handing in quickfilver, the whole 
produce continued a confiderable time without any 
change of dimenfions. I then introduced a 
fmall quantity of water to it, when about three 
fourths of it (the whole being about four ounce 
meafures) prefently, but gradually, difappeared, the 
quickfilver riling in the veflel. I then introduced a 
confiderable quantity of watery but there was no 
farther diminution of the air, and the remainder I 
found to be inflammable. 
Having frequently continued this procefs a long 
time after the admiflion of the water, I was much 
amufed with obferving the large bubbles of the newly 
generated air, which came through the quickfilver, 
the fudden diminution of them when they came to 
the water, and the very fmall bubbles which went 
H h a through 
