Analy/is of the Air. 243 
lungs is much more capacious than 226 cil* 
bids inches ; for Dr. Jurin y by an accurate 
Experiment* found that he breathed out* 
at one large expiration* 220 cubick inches 
of air; and I found it nearly the fame* 
when I repeated the like Experiment in an- 
other manner : So tfyat there muft be a large 
allowance made for the bulk of the re- 
maining air, which could not be expired 
from the lungs ; and alfo for the fubftance 
of the lungs* 
Suppofing then* that according to Dr. Ju- 
rms eftimate (in Motfs Abridgment of the 
c Philofophical TranfaEf. Vol. I. p. 415.) we 
draw in at each common infpiration 40 cii* 
bick inches of air, that will be 48000 cu- 
bick inches in an hour* at the rate of 20 in- 
fpirations in a minute. A confiderable part 
of the elafticity of which air is, we fee by 
the foregoing Experiment* conftantly de« 
ftroyed, and that chiefly among the veficles* 
where it is charged with much vapour. 
But it is not eafy to determine how much 
is deftroyed. I attempted to find it out by 
the following Experiment, which I fhall here 
give an account of* tho’ it did not fhcceed 
fo well as I could have wiflied* for want of 
much larger veflels 5 for if it was repeated 
R % with 
