Gbfervatiom on inflammable Air. 341 
receivers full of inflammable air extra-fled from zinc, 
and from iron, through water. The birds died within a 
few feconds, that is, juft as they did when their nofes 
were unftopped. Quadrupeds were tried after the fame 
manner, and the event was the fame. 
Having in this manner exploded this new hypothelis, 
there remained one more, which feemed to fuggeft a pro- 
bable reafon (fince fome reafon there muft be) for Mr. 
sheele’s experiments being attended with refults fo dif- 
ferent from thofe of other experimenters. When an ani- 
mal is introduced into a veflel of inflammable air, its 
whole body is expofed to that air ; and it is not yet known 
by philofophers what diforders that fluid may occafion to 
the animal frame. It is true that none are obferved to be 
produced by other noxious kind of air; but if it be con- 
fldered, that the vapours of fulphur make a great im- 
preflion upon frogs, even when thofe animals do not 
breathe them, but have their afpera arteria tied up, it will 
not feem impofiible for the inflammable air, in fome 
manner or other, to a <fl upon the body of animals. It 
may, perhaps, hinder the perfpiration ; it may infinuate 
itfelf through the pores of the Ik in ; in fliort, its adtion 
upon the body feems probable till experiments evince 
the contrary. 
Vo l. LXIX. Z z I therefore 
