relating to Air and Water, ^oy 



gave an addition of fix grains to the piece of iron which had 

 been melted in it. But there was always a quantity of fixed 

 air produced in this procefs ; and on the fuppofition that this 

 air confifts of the union of dephlogifticated and inflammable 

 air, it proves that the dephlogifticated air which enters the 

 iron expels more phlogifton than is neceflary to conftitute an 

 cqnal weight of water, fo ih^t water does not contain fo much 

 phlogiflon as iron ; but the difference is not very confiderable. 



Admitting Mr. Kirwan's conclufion, viz. that loo cubic 

 inches of fixed air contain 8, 35 7 grains of phlogifton, the. 1 3 ounce 

 meafure of fixed air, which (in an experiment recited in thefe 

 papers) was found in the refiduum of feven ounce meafures of 

 dephlogifticated air abforbed by iron, would not have contanied 

 more than .oi grain of phlogifton, or about .16 ounce mea- 

 fure of inflammable air. Then, as the abforption of 12 

 ounce meafures of d^phlogifticated air occafioned an addition of 

 6 grains to the weight of the iron which had abforbed it, the 

 abforption of feven ounce meafures mufl have occafioned the 

 addition of 3.5 grains to the iron which had imbibed it. But 

 the fame addition of weight to iron given hjj^eam (which car- 

 ries its own inflammable air along wdth it) would have expelled 

 near 12 ounca meafures of inflammable air: confequently, 

 about ten ounce meafures of inflammable air (or the phlogiuon 

 requifite to form it) muft, in the former experiment, have been 

 retained in the iron> in order to compofe the water which was 

 now made by the union of the dephlogifticated air imbibed by 

 the iron and the phlogifton contained in it : and therefore the 

 proportion between the quantity of phlogifton in won to that 

 which is contained in an equal weight of w^ater, may be about 

 12 to 10, or more accurately to 10.4. 



Had no fixed air at all been found in the refiduum above- 

 nientlGned, it might have been concluded, that water had cori- 



R r 2. tained 



