2 g6 Mr. Bell on the nerves which associate the muscles 
in inspiration, the head, and consequently the upper extremity 
of the muscle, are fixed. Now, if we endeavour to raise the 
sternum through the operation of this muscle, we shall find 
that other muscles are, insensibly to us, brought into action, 
which have nothing to do with this raising of the sternum. 
For example ; if we strain to raise the lower extremity of the 
muscle, we shall unavoidably produce an action of the muscles 
of the nostrils ; by which association of actions, we shall dis- 
cover, that we are using the mastoideus as a respiratory 
muscle. If we reverse the action, and move the upper ex- 
tremity of the muscle, other muscles will be drawn into co- 
operation, but they will be such as assist in the motion given 
to the head. Or we may vary the operation in another way. 
In snuffing or smelling, if we place the fingers on the por- 
tions of the mastoid muscles which are attached to the ster- 
num, we shall find every little motion of the nostrils accom- 
panied with corresponding actions of the sternal portions of 
the muscles in the neck. 
A man having a complete hemiplegia, the side of his face 
relaxed, the arm hanging down powerless, and the leg 
dragged in walking, we were curious to know if the influence 
pervaded all the nerves of the side, or only the regular or 
voluntary nerves. Some trouble was taken to make him 
heave up the shoulder of the debilitated side, but to no pur- 
pose. He could only do it by bending the spine to the other 
side, and as it were weighing up the paralytic shoulder. But 
on setting him fairly in front, and asking him to make a full 
inspiration, both shoulders were elevated at the same time 
that both the nostrils were in motion. The respiratory nerve 
of the face, and the superior respiratory nerve, were entire 
