24 ° Analyfis of the Air. 
fpccifick gravity of the fubftance of the 
lungs, (which is a continuation of the 
branchings of the wind-pipe, and blood- 
vefiels) by finding the fpecifick gravity of 
the wind-pipe, which I had cut off •, it was 
to Well-water as r.oj to i. Andacubick 
inch of water weighing 254 grains ; I 
thence found by weighing the lungs the 
whole of their folid fubftance to be equal 
to 37 cubick inches. 
I then filled a large earthen vefiel brim 
full of water, and put the lungs in, which 
I blew up, keeping them under water with 
a pewter plate. Then taking the lungs out 
and letting the plate drop to the bottom of 
the water, I poured in a known quantity of 
water, till the vefiel was brimful again; that 
water was 7 pounds 6 ounces and t, equal 
to 204 cubick inches ; from which deduct- 
ing the fpace occupied by the folid fubftance 
of the lungs, viz. 37 -]- -f cubick inches, 
there remains 166 i. cubick inches for 
the cavity of the lungs. But as the Pul- 
monary Veins, Arteries and Lymphaticks 
will, when they are in a natural ftate re- 
plete with blood and lymph, occupy more 
fpace than they do in their prefent empty 
ftate; therefore fome allowance mull alfo 
be 
