relating to Air and Water, 301 



of moijlure came over, but a prodigious quantity of air^ and 

 the rapidity of its produdlion aftonifhed me ; fo that I had no 

 doubt but that the weight of the air would have been equal to 

 the lofs of weight both in the fcales and in the charcoal ; and 

 when I examined the air, which I repeatedly did, I found it to 

 contain one-tenth of fixed air, and the inflammable air, which 

 remained when the fixed air was feparated from it, was of a 

 very remarkable kind, being quite as heavy as common air. 

 The reafon of this was fufficiently apparent when it was de~ 

 compofed by means of dephlogiflicated air ; for the greateil: 

 part of it was fixed air. 



The theory of this procefs I imagine to be, that the phlo- 

 gifton from the charcoal reviving the iron, the water with 

 which it had been faturated, being now fet loole, affe^^led the 

 hot charcoal as it would have done if it had been applied to it 

 in the ionno^Jieam as in the preceding experiments; and there- 

 fore the air produced in thefe two difi^erent modes have a near 

 refemblance to each other, each containing fixed air, both com- 

 bined and uncombined, though in different proportions ; and 

 in both the cafes I found thefe proportions fubjeO: to variations. 

 In one procefs with charcoal and fcales of iron, the firfi: pro- 

 duce contained one-fifth of uncombined fixed air, the middle 

 par) one-tenth, and the laft none at all. But in ail thefe cafes 

 the proportion of combined fixed air varied very little. 



Why air and not water fhould be produced in this cafe, as 

 well as in the preceding, when the iron is equally revived in 

 both, I do not pretend perfectly to underftand. There is, in- 

 deed, an obvious difiierence in the circumftances of the tvvo 

 experiments ; as in that with charcoal the phlogiflon is found 

 in a combined flate ; whereas in that of inflammable air, it is 



ioofcj 



