Atmospheric Air and Oxygen Gds by Respiration . 255 
derived fresh confidence from the remarkable coincidence 
and uniformity of the results. No precaution was at any 
time omitted which appeared to us necessary to insure 
accuracy. 
One hundred parts of the expired gas being agitated with 
lime water in the eudiometer, the lime water became tur- 
bid, and 8.5 parts of the gas were absorbed, which were 
consequently carbonic acid ; the remaining 91 .5 parts were 
treated with the green sulphate of iron, saturated with nitrous 
gas, as recommended by Professor Davy, and afterwards 
with the simple solution of the green sulphate, when 12.5 
parts were absorbed, which were consequently oxygen, and 
the remaining 79 azote. 
100 parts of the expired gas therefore consisted of 
8.5 carbonic acid. 
12.5 oxygen. 
79. azote. 
100 
The air contained in the water gasometer, previous to the 
experiment, being examined by the same tests, consisted 
in 100 parts of 
21 oxygen, 
79 azote. 
100 
In trying common atmospheric air with lime water, we 
could never find any quantity of carbonic acid perceptible in 
the eudiometer of 100 parts. 
