414 Mr. Bell's experiments on the structure 
When an animal becomes insensible from loss of blood, 
the impression at the heart extends its influence in violent 
convulsions over all the muscles of respiration ; not only is the 
air drawn into the chest with sudden and powerful effort, but 
at the same instant the muscles of the mouth, nostrils, and 
eyelids, and all the side of the face, are in a violent state of 
spasm. In the ass, where the respiratory nerve of the face 
had been cut, the most remarkable contrast was exhibited 
in the two sides of its face ; for whilst the one side was in 
universal and powerful contraction, the other, where the 
nerve was divided, remained quite placid 
From these facts we are entitled to conclude, that the port io 
dura of the seventh, is the respiratory nerve of the face ; 
that the motions of the lips, the nostrils, and the velum 
palati are governed by its influence, when the muscles of 
these parts are in associated action with the other organs of 
respiration. These passages to the lungs are membranous 
tubes, moved by muscles, which serve to expand and widen 
them, so that the air may freely enter into the lungs. It is ob- 
vious that to produce this, these muscles must have a consent 
with the other muscles of respiration, and move simultane- 
ously with them ; and this is effected through the respiratory 
nerve of the face. It shall be proved in the sequel, that the 
throat, neck, shoulders, and chest, have similar nerves to 
this, similar in structure and function, and that these unite all 
the extended apparatus of breathing and speaking. 
The actions of sneezing and coughing are entirely con- 
fined to the influence of the respiratory nerves. When 
carbonate of ammonia was put to the nostrils of the ass whose 
respiratory nerve had been cut, that side of the nose and face 
