relating to Air and fV \ ater. 285 
containing inflammable air, confined by water, threw upon it 
the focus of the lens, and prefently perceived the inflammable 
air to difappear, and without thinking of any thing efcaping 
from, the calx of iron (which had been fubje&ed to a greater 
heat before) I imagined that I fhould have found the addition of 
the weight of air in the iron, and the refult might be an iron 
different from the common fort. But I found, to my furprife, 
that the iron, which had exhibited no new appearance in this 
mode of treatment, had loft weight, inftead of gaining any. 
The piece of iron on which I made this firft experiment weighed 
n| grains, and ounce meafures of inflammable air haddif- 
appeared while the iron had loft 2f grains. 
Confidering the quantity of inflammable air that had difap- 
peared, viz. 7 f ounce meafures, and the dephlogifticated air 
which had been expelled from the iron, viz. 2§ grains, which 
is equal to about 4.1 ounce meafures, I found that they were 
very nearly in the proper proportion to fat;urate each other, 
when decompoied by the electrical fpark, viz. two meafures of 
inflammable air to one of dephlogifticated air. I therefore had 
now no doubt but that the two kinds of air had united, and 
had formed either fixed air or water ; but which it was I could 
not tell, having had water on the receiver in which the experi- 
ment was made, and having negleCted to examine the ftate of 
the air that remained, except in a general way, by which I 
found, that it was ftill, to appearance, as inflammable as ever. 
With a view to determine whether fixed air , or water , would 
be the produce of this mode of combining inflammable and 
dephlogifticated air, I repeated the experiment in a veflel in 
which the inflammable air was confined by mercury, and both 
the veflel and the mercury had been previoufly made as dry as 
poflible. I had no fooner begun to heat the iron, or rather Jlag, 
6 in 
