Loeey J 
is it not more reafonable to fay that 
vegetables contain an air, or by 
whatever name you will pleafe to 
call it, which by undergoing dif- 
Feit! operations changes into dif- 
ferent forts of air? 
Whoever therefore fays, that fuc 
or fuch fubftance contains fuch or 
fuch air, becaufe he extracts fuch 
air from it by the action of fire; by | 
fermentation, or by any other ee 
‘may fpeak erroneoutly. an 
Nitrous acid, or fpirit of “nitre, 
Fields nothing but nitrous air when 
it is poured upon mercury, coppéet, 
iron, &c.; but, when it is mixed with 
iron filings in a very diluted ftate, it 
“gives, by the affiftance of a mo- 
derate degree of heat, a mixture 
of different airs, partly fixed, partly 
common air, and partly phlogifti- 
"es air, (which experiment I faw 
3 at 
