280 Dr. Priestley’s Experiments and Obfervations 
concluded from fome experiments, of which I gave an account 
to the Society, and alio from fome obfervations of his own, 
that water confifts of dephlogifticated and inflammable air, 
in which Mr. Cavendish and M. Lavoisier concur with 
him; but Mr. Lavoisier is well known to maintain, that 
there is no f uch thing as what has been called phiogijlon , affirm- 
ing inflammable air to be nothing elfe but one of the elements 
or conftituent parts of water. In the following experiments I 
alfo had a particular view to a conclufion which I had drawn 
from thofe experiments, of which an account is given in my 
laft communications to the Royal Society ; viz. that inflam- 
mable air is pure phlogifton in the form of air, at leaft with 
the element of heat ; and that fixed air conflfls of dephlogifti- 
cated and inflammable air ; both which doflrines had been firft 
advanced by Mr. Kir wan, before I had made the experiments 
which I then thought clearly proved them. 
Such were the hypothefes to which I had a view when I 
began the following courfe of experiments, which I hope will 
be an admonition to myfelf, as well as to others, to adhere as 
ngoroufly as poffible to actual obfervations , and to be extremely 
careful not to overlook any circumftance that may poffibly con- 
tribute to any particular refult. I fhall have occaflon to notice 
my own miftakes with refpecfc to conclufons , though all the 
faffs were ftriflly as I have reprefented them. But whilft phi- 
lofophers are faithful narrators of what they obferve, no perfon 
can juflly complain of being milled by them; for to reajon 
from the faffs with which they are fupplied is no more the 
province of the perfon who difeovers them, than of him to 
whom they are difeovered. 
One of the moll Ample of all phlogiftic proceffes is that in 
which metals are ignited in dephlogifticated air. I therefore 
^ began 
