350 Abbe Fontana’s 'Experiments and 
air of the bladder breathed three times ; h.ence this loft 
ten parts by the mixture of nitrous air. 
This explanation, which it is neceffary to adopt after 
having exploded all the other hvpothefes, is very analo- 
gous to the above related experiment of the fmaller blad- 
der filled with inflammable air which was breathed ele- 
ven times fucceflively. This air was breathed after a 
natural expiration, fo that there ftili remained in the 
lungs about feventy-five inches of common air. Thefe 
feventy-five inches of. pulmonary air, together with the 
eighty inches of inflammable air, were infixed together 
during the eleven infpirations and expirations; hence 
the air of the bladder was a mixture of nearly equal por- 
tions of inflammable and common air; and, accordingly, 
when tried with the nitrous air, it was found to be. much 
better (though it had been breathed eleven times) than 
the air of the large bladder breathed three times only, 
after the lungs had been emptied as much as poffible. 
All the other experiments that I have naade in confir- 
mation of this hypothefis leem univerfally to favour it. 
If a Guinea pig is introduced into a receiver containing 
400 cubic inches of inflammable air, or a fmall bird into 
only fifty inches of it, and they be left therein till they 
are dead, that air afterwards will not be fenfibly dimi- 
ni (lied 
