APPENDIX. 285 
Inches Depth of Air ; a Quantity equal to one 
fourth of the whole Capacity of the Glaft 
VelTel ajy and it did the fame a fecond, third 
and fourth timej on the fifth Admiffion of 
frefli Air, it abforbed but 3 +:^ Inches Depth, 
but on the fixth Admiffion no more was ab- 
forbed, nor was the Air turbid. 
4. The Bolt-head b with its contained ef. 
fervefcenc Ma(s, I placed under a freffi Glafs, 
upon which it abforbed of this frefli included 
Air, fafter than the effervefeent Mixture ge- 
nerated Air, fo that the Water rofe in the in- 
verted Glafs ; but after fome time, the Water 
changed to a fubfiding State, an Argumenc 
that more Air was then generated than ab- 
forbed. 
y. This Air inftantly extinguiflies a Can- 
dle, as do moft of the Airs which are tainted 
with the Fumes of thefe effervefeent Mixtures. 
6, Spirit of Nitre with an equal Qiianticy 
of Water poured on Filings of Steel, abiorb- 
cd in an Hour a good Quantity of Air : Three 
Hours after, when the Air in the Glaft a y 
was clear, I let in a like Quantity of frefli Air^, 
but this did not make the Air in the Glafs tur- 
bid, nor was any of the frefli Air abforbed. 
Yet when at another time I let the like Mix- 
ture 
