35a Abbe fontana’s Experiments and 
ting it out of my mouth. In this manner a flame may 
be produced from the mouth, of various inches in length, 
and two or more inches in breadth. 
But whence does that fenfation of levity and faci- 
lity of breathing the inflammable air, which I have de- 
fcribed above, originate? At prefent I can only have 
recourfe to a mere mechanical caufe for a folution, for 
I do not obferve in inflammable air any property that 
feems capable of altering the lungs upon a chemical 
principle; neither have I obferved any decompofltion 
of air, or alteration of the fluids of the animal. It 
has been obferved, that inflammable air, after being 
breathed, comes out of the lungs with the fame pro- 
perties it had before. It is alfo known, that inflam- 
mable air is not fenfibly abforbed by water, at leaft after 
a fhort time. The lungs, or more properly the pulmo- 
nary veficles, are continually moiftened with fluids; but 
that air cannot be abforbed by them, except it be firfl de- 
compofed. Nothing elfe therefore remains to which we 
can have recourfe for an explanation of the above men- 
tioned fenfations, but the well known levity of the in- 
flammable air compared with common air. And indeed 
the fenfation I felt when I breathed that air, is like that 
of a very light fluid which does not opprefs the lungs, 
and is hardly felt. This explanation agrees exactly with 
fome 
