304 Mr. Milner on the Produttion of 
7. Laftly, I determined to try the effeCt of the gun-barrel 
upon depl logifticated nitrous air, as from all that I had feen 
it feemed reafonable to expeCt, that this fpecies of air would 
be the eafieft reduced to the ftate of phlogifticated air. For 
this purpofe, I diluted a faturated folution of copper in the 
nitrous acid, and put pieces of iron wire into it, and as the 
neck of the retort which contained the folution was luted to 
one end of the gun-barrel, the dephlogifticated nitrous air 
was expofed in its paffage to the aCtion of the red-hot tube, 
and alfo to the furfaces of the red-hot iron turnings which it 
contained. In this cafe, when the procefs is conduced with 
proper care, all the air which is received at the other end of 
the tube will be found phlogifticated. 
8. When the air received at the end of the gun-barrel 
was in the laft mentioned ftate, viz. perfectly phlogifti- 
cated, I have frequently obferved a white fume ifluing along 
with the air, and fometimes afcending through the water or 
mercury into the glafs receivers. Upon examining this white 
fume, I foon perceived by the fmell that it contained volatile 
alkali. I was much ftruck with the obfervation, and imme- 
diately recolleCted Dr. Priestley’s relation of a fimilar pro- 
duction by expoftng nitrous air to pieces of iron. 
9. Moft of the experiments hitherto related were made in 
the fummer of 1786; in general they agree with thofe of 
Dr. Priestley; the changes and productions are much the 
fame, and the only new circumftance is, as was obferved at 
art. 5. The fame effeCts are brought about injlantly by the 
aCtion of red-hot iron, which require much time by the me- 
thod of Ample expofure to cold iron. 
. For which reafon, though it gave me much pleafure at the 
time to fee fuch curious tranfmutations brought about in a few 
minutes^ 
