308 Dr. Priestley's Experiments and Obfervatkns 

 tained the very fame proportion of phlogiflon with iron. Since 

 when iron that has been faturated with dephlogifticated air is 

 heated in inflammable air (in which procefs an equal weight of 

 water is produced, and the lofs of weight in the iron is equal to 

 that of fuch a quantity of dephlogifticated air as would have 

 been one- h^] if of the bulk of the inflammable air which difap- 

 pears in that procefs) it might have been concluded, that one- 

 fifth of any quantity in water had been inflammable air. 



For, neglecting the difference between the weight of dephlo- 

 gifticat-ed and common air, which is not confiderable, and efci- 

 mating the latter -^-s^-^-th part of water, and inflammable air at 

 one-tenth of the weight of common air, an ounce meafure of 

 dephlogiilicated air will weigh ,6 grain, and two ounce mea* 

 fures of inflammable air will weigh .12 grain, which num- 

 bers are to each other as 5 to i *. 



Though, in confequence of the fmall quantity of fixed air 

 Avhich is found in the procefs of melting iron in dephlogifli- 

 •cated air, this conclufion is not accurate, it is pretty nearly 

 fo ; and it is remarkable that, upon tliis fuppofition, about as 

 ;nuch inflamxmable air is expelled from iron when water is com- 



* It appears from the prolccHtion of thefe experiments, that the water which 

 is found on Jieating tfee leaks of iron m inflammable air, is not formed by the 

 dephlogifticated air expelled from rhera uniting with the inilammable air in the 

 veiTel, but was the water previonfl.y contained in the fcales^ which is made to quic 

 its place by the introdutlion of the phlogiflon from the inflammable air; yet that 

 water carries out with it not much lefs phlogifton than was taken in by the iron, 

 3nd a little more mml be allowed for that water which was neCefTary to make 

 inflammable air, and which could not enter the iron when it was revived ; fo thar^ 

 on the whole, the phlogifton in the water that is found after the procefs muft be 

 very inearly the fame quantity that is imbibed by the iron, and the water is nearly 

 the fame that would have been produced, on the fuppofition of its being made 

 from dephlogifticated air exp'jiled from the fcales uniting with the inflammable 

 air in the vcflel. 



