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I could judge, it was ftill as inflammable as ever. 
Another quantity of inflammable air was alfo redu- 
ced in the fame proportion, by a moufe putrefying 
in it; but its inflammability was not feemingly 
lefiened. 
Air diminifhed by this mixture of iron filings and 
brimftone, is exceedingly noxious to animals, and 
I have not perceived that it grows any better by- 
keeping in water. The fmell of it is very pun- 
gent and offenfive. 
The quantity of this mixture which I made ufe of 
in the preceding experiments, was from two to four 
ounce meafures ; but I did not perceive, but that 
the diminution of the quantity of air (which was 
generally about twenty ounce meafures) was as great 
with the fmalleft, as with the largefl quantity. How 
fmall a quantity is neceflary to diminifh a given 
quantity of air to a maximum , I have made no ex- 
periments to afcertain. 
As foon as this mixture of iron filings, with briin- 
flone and water, begins to ferment, it alfo turns black, 
and begins to fwell, and it continues to do fo, till it 
occupies twice as much fpace as it did at firft ; and 
the force with which it expands is great; but how 
great it is I have not endeavoured to determine. 
When this mixture is immerfed in water, it gene- 
rates no air, though it becomes black, and fwells. 
E e VI. Of 
Vol. LXII. 
