434- Dr, Priestley’s Experiments relating to Phlogifton , 
effected with more time and difficulty. Forty ounce meafures 
of this kind of inflammable air I reduced to 25 ; when I found 
that the heat of the lens produced only giafs of lead, and no 
tneial. The air was ftill, however, inflammable; and there 
was a (mail mixture of fixed air in it. This kind of inflam- 
mable air, which burns with a lambent flame, I have fome rea- 
ion to think, confifts of an intimate union of fixed air with 
that which is of the explofive kind extracted from metals. The 
refult of thofe experiments which I made with that kind of 
inflammable air which is collected in the procefs for making 
phofphorus, and which burns with a lambent yellow flame, 
was limilar to thofe which I made with inflammable air from 
wood, which burns with a lambent white flame. 
Having had this remarkable refult with inflammable air, I 
immediately tried all the other kinds of air in the fame man- 
ner ; but in none of them did I procure any thing from the 
minium befides giafs of lead, except in alkaline air, and vi- 
triolic acid air. In fixed air, nitrous air, phlogiflicated air, 
marine acid air, fluor acid air, as alfo in common and dephlo- 
gifticated air, I got no metal at all. In vitriolic acid air there was 
but a fmall quantity of lead produced, and 1 have obferved 
that this kind of air imparts a certain portion of phlogifton to 
common air, rendering it in fome meafure phlogiflicated, 
though by no means in fo great a degree as nitrous air. Though 
nitrous air and phlogiflicated air certainly contain phlogifton, 
they appear by thefe experiments to hold it too ohftinately to 
part with it to minium in this procefs, though nitrous air quits 
it fo readily to refpirable air. I would obferve, that there were 
fome peculiar appearances in the experiments I made to revive 
the calx of lead in thefe kinds of air in which the attempt did 
1 not 
