Mr. CavennisH’s Experiments on Air. 167 
phofphoric acid gains:is a {trong additional inducement to think 
that it abforbs fixed air. During the combuftion of vegetable 
fubitances, I think it highly probable that fixed air is formed, 
both from my own experiments on the combuttion of wax can- 
dles, and that mentioned in the firft volume of Dr. Priest- 
LEY’S Obfervations, p- 1363 but when inflammable air from 
metals and dephlogifticated air are fired, as a great diminution 
takes place, . and yet no fixed air is found, I am nearly con- 
vinced, by Mr. CavenpIsH’s experiments, that water is really 
produced ; ; noram I furprized that, in this inftance, the union of 
phlogitfton ; and dephlogifticated air fhould form a compound very 
different from that which it forms in other inftances of phlo- 
giftication, but fhould rather be led to expect it a priort; for in 
this cafe the phlogifton is in its moft rarefied known ftate, and 
unites to dephlogifticated air, the fubftance to which it has 
the greateft affinity, in circumftances the moft favourable to 
the clofeft and moft intimate union ; for both, in the a& of 
inflammation, are rarefied to the higheft degree ; both give out 
their f{pecific fire, the great obftacle to their union, it being by 
the inflammation converted into Jenfible heat (a circumftance 
which, im my opinion, conftitutes the very eflence of flame); the 
refulting compound having then loft the greateft part of its 
fpecific fire, is neceflarily reduced, according to Dr. BLack’s 
theory, into a denfer ftate, which the prefent experiment fhews 
to be water; whereas, in common cafes of combuftion, the 
phlogifton being denfer and lefs divided, unites lefs intimately 
‘with the dephlogifticated part of common air, confequently ex- 
pels lefs of its {pecific fire, and therefore forms lefs denfe com- 
pounds, vz, fixed and phlogifticated airs; and fo much the 
more, as a great part intirely efcapes combuftion ; but it feems 
probable 
