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with this obfervation, that burned air is farthel* 
dimininiShed both by putrefa&ion, and a mixture 
of iron filings and brimftone; and I therefore, 
take it for granted, by every other caufe of the 
diminution of air. It is probable, therefore, that 
burned air is air fo far loaded with phlogifton, as 
to be able to extinguish a candle, which it may 
do long before it is fully Saturated. 
Inflammable air with a mixture of nitrous air 
bu rns with a green flame. This makes a very 
pleating experiment when it is properly conduced. 
As, for tome time, I chiefly made ufie of copper 
for the generation of nitrous air, I firft afcribed 
this circumftance to that property of this metal, 
by which it burns with a green flame ; but I was 
prefently fatisfied that it muSt arife from the Spirit 
of nitre, for the effect is the very fame from which- 
ever of the metals the nitrous air is extra&ed, all 
of which I tried for this purpofe, even Silver and 
gold. A mixture of oil of vitriol and fpirit of 
nitre in equal proportions diflblved iron, and the 
produce was nitrous air ; but a lefs degree of fpirit 
of nitre in the mixture produced air that was in- 
flammable, and which burned with a green flame. 
It alfo tinged common air a little red, and dimi- 
nished it, though not much. 
The diminution of common air by a mixture of 
nitrous air, is not fo extraordinary as the diminu- 
tion which nitrous air itfelf is fubjedl to from a 
mixture of iron filings and brimftone, made into a 
pafte with water. This mixture, as I have already 
obferved, diminishes common air between one 
fifth and one fourth, but has no fuch effect upon 
7 any 
