46 
MKMOlIl OF CA.MI’EIi. 
versed tlic cx peri me lit, by introducing tlie instru- 
ment into the windpipe, and discovered that the air 
escaped througli the suiall hole 1 had drilled. W lien 
I drilled a hole in the bone of the thigh, the same 
results did not follow. 
“ It happened that tlie chest of the eagle liad 
been too much injured by the shot to allow me to 
repeat all the e.xperiments upon it. However, I di- 
rected a stream of air through its thigh-bone, and 
perceived that the lining membrane of the lungs, 
which extended into the abdomen, formed a mem- 
branous conduit, which, running along with the ves- 
sels of the leg, terminated at the foramen in the 
thigh-bone, and thus offered a free passage by which 
the air could enter. This redoubled my ardour to 
push my researches farther. ’ 
He then made experiments upon the turkey-cock, 
and other domestic fowls, and also on the stork and 
heath-cock. In the former, the structure was like 
that of the owl : in the latter, again, it resembled 
that of the eagle ; and, from this circumstance, he 
inferred, that the transmission of air into the thigh- 
bones was not common to all birds, but peculiar to 
those which were strong on the wing. He also ex- 
amined a great number of our most common birds, 
such as the sparrow, the lark, &c. and thereby found 
his views so far confirmed. 
In conclusion, be remarks (for we must not ex- 
tend our analysis further), “ I flatter myself that I 
have discovered, that, in many birds, and more es- 
