2'8o Dr. Priestley's Experiments and Obfervatwns 



concluded from fome experiments, of which I gave an account ^ 

 to the Society, and alfo from fome obfervations of his own, I 

 that water confifts of dephlogifticated and inflammable air, 

 in which Mr. Cavendish and M. Lavoisier concur with i 

 him; but Mr. Lavoisier is well known to maintain, that j 

 there is no fuch thing as what has been called phlogijlon, 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 viev/ to a concluiion which I had drawn 

 from thofe experiments, of which an account is given in my 

 laft communications to the Royal Society ; ^'/z. that inflam- 

 mable air is pure phlogifton in the form of air, at lead with 

 the element of heat ; and that fixed air confifls of dephloglfti- 

 Gated and inflammable air ; both which do£lrines had been firfl; 

 advanced by Mr. Kirwan, before I had made the experiments 

 which I tlien 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 a(Jmonition to myfelf, as well as to others, to adhere as 

 rigoroufly 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 (hall have occafion to notice 

 my own miilakes with refped to conchifions, though all the 

 faBs were (Iridly as I have reprefented them. But whllft phi- 

 lofophers are faithful narrators of what they obferve, no perfoii 

 can juftly complain of being milled by them ; for to reajon 

 from the fads with which they are fupplied is no more the 

 province of the perfon who difcovers them, than of him to^ 

 whom they are difcovered. 



One of the mod fimple of all phlogiftic proceiTes is that \\\ 



which metals are ignited in dephlogifticated air. I therefore 



3 began 



