296 Dr. Priestley’s Experiments 
It) of iron in dephlogifticated air, appears to me to be very 
evident, as well as in the procefs with fleam. 
That fixed air is found in the veflel in which iron is melted 
In dephlogifticated air, I obferved before ; but I never took 
much care to afcertain the quantity of it. This I have lately 
done in many inftances, and in all of them find it to be much 
more confiderable than can be accounted for, by fuppofing it to 
come from plumbago in the very fmall quantity of iron that I 
melted ; fo that it muft neceflarily have been formed by the phlo- 
gifion from the iron, and the pure air in the veflel, at the fame 
time that the iron became finery cinder by imbibing water from 
the air ; and I have fhewn, that by far the greateft part of the 
weight of this air is water. The experiments were made with 
a very good burning lens, of fixteen inches diameter, with 
which Mr. Parker has generoufly furniflied me; and by 
means of it I can now make thefe experiments, which require a 
great degree of heat, with much more eafe and certainty than 
1 could do before. 
In 6| oz. meafures of dephlogifticated air I meited turnings 
of malleable iron till there remained only if oz. meafure, and 
of this oz. meafure was fixed air. In 6 oz. meafures of 
dephlogifticated air, of the ftandard of 0.2, I melted iron till 
it was reduced to two-thirds of an ounce«meafure, of which 
one- half was fixed air, and the remainder completely phlo- 
gifticated. Again, I melted iron in yf oz. meafures of de- 
phlogifticated air, of the fame purity with that in the laft ex- 
periment, when it was reduced to 1 f oz. meafure, and of this 
four-fifths was fixed air, and the remainder phlogifticated. In 
this cafe I carefully weighed the finery cinder that was formed 
111 the procefs, and found it to be nine grains, fo that the iron 
that had been meited (being about two-thirds of this weight) 
had 
