[ x 78 ] 
Confidering inflammable air as air united to or 
loaded with phlogifton, I expofed to it feveral fub- 
ftances, which are faid to have a near affinity with 
phlogifton, as oil of vitriol, and fpirit of nitre (the 
former for above a month), but without making any 
fenffble alteration in it. 
I obferved, however, that inflammable air, mixed 
with the fumes of fmoaking fpirit of nitre, goes off 
at one explofion, exactly like a mixture of half com- 
mon and half inflammable air. This I tried feveral 
times, by throwing the inflammable air into a phial 
full of fpirit of nitre, with its mouth immerfed in a 
bafon containing fome of the fame fpirit, and then 
applying the flame of a candle to the mouth of the 
phial, the moment that it was uncovered, after it 
had been taken out of the bafon. This remarkable 
efted I haftily concluded to have arifen from the in- 
flammable air having been in part deprived of its in- 
flammability, by means of the ftronger affinity, 
which the fpirit of nitre had with phlogifton, and 
therefore I imagined that by letting them ftand longer 
in contact, and efpecially by agitating them ftrongly 
together, I fhould deprive the air of all its inflam- 
mability ; but neither of thefe operations fucceeded, 
for ftill the air was only exploded at once, as before. 
And laftly, when I pafled a quantity of inflammable 
air, which had been mixed with the fumes of fpirit 
of nitre, through a body of water, and received it in 
another vefiel, it appeared not to have undergone 
any change at all, for it went off in feveral fucceflive 
exploffons, like the pureft inflammable air. The 
effed abovementioned muft, therefore, have been 
owing to the fumes of the fpirit of nitre fupplying 
