relattng to Air and IVaier. -^oy 



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

 been melted in it. But there was always a quantity oi 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 neceffary to conftitute an 

 equal weight of water, fo that water does not contnin fo much 

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



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

 inches of fixed air contain 8,357 grains of phlogifton, the . 1 3 ounce 

 meafure of fixed aiif, 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 contained 

 more than .01 grain of phlogifton, or about .16 ounce mea- 

 fure of inflammable air. Then, as the abforption of 22 

 ounce meafures of dephlogifticated air occafioned an addition of 

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

 abforption of feven ounce meafures muft have occafioned the 

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

 the fame addition of weight to iron given hyjlemn (which car- 

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

 near 12 ounce meafures of inflammable air: confequenth ., 

 about ten ounce meafures of inflammable air (or the phlogifioii 

 requifite to form it) mufi-, 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 dephlogifiicated air imbibed by 

 the iron and the phlogifi:on contained in it: and therefore the 

 proportion between the quantity of phlogifton in iroji to that 

 which is contained in an equal weight of water, may be about • 

 12 to 10, or more accurately to 10.4. 



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

 mentioned,, it might have been concluded, that water had con- 



R r 2 tained 



