^00 Dr. Priestley's Expenments and Obfcr-vations 



rated with water, is expofed to heat In inflammable air, this 

 air enters into it, deftroys the attradion between the water and 

 the earth, and revives the iron, while the water is expelled in 

 its proper form. 



Confequently, in the procefs with y?f^/«, nothing is neceflary 

 to be fuppofed but the entrance of the water, and the expul- 

 lion of the phlogifton belonging to the iron, no more phlo- 

 gifton remaining in it than what the water brought along with 

 it, and which is retained as a conflituent part of the water, 

 or of the new compound. 



Having procured water from the fcales of iron (which I mufl 

 again obferve is, in all refpe<3:s, the fame fubflance with iron 

 melted in dephlogiftlcated air, or faturated with fteam by means 

 of heat) and havii^g thereby converted it into perfecl iron again, 

 I did not entertain a doubt but that I fyiould be able to produce 

 the fame effecl by heating it with charcoal in a retort; and I 

 had likewife no doubt but I fhould be able to extraft the addi- 

 tional weight which the iron had gained (viz. one-third of the 

 whole) in water. In the former of thefe conje6lures I was 

 right ; but with refpe6t to the latter, I was totally miftaken. 



Having made the fcales of iron, and alfo the powder of 

 charcoal very hot, previous to the experiment, fo that I was 

 fatisfied that no air could be extracted from either of them fe- 

 parately by any degree of heat, and having mixed them toge- 

 ther while they were hot, I put them into an earthen retort, 

 glazed within and without, which v/as quite impervious to air. 

 This I placed in a furnace, in which I could give it a very 

 llrong heat ; and conne6led with it proper veffels to condenfe 

 and colle^l the water which I expe£led to receive in the courfe 

 of the procefs. But, to my great furprife, not one particle 



of 



