Mr. Bell on the motions of the eye , &c. 
175 
Experimental enquiry into the action of these muscles . 
I. I divided the superior rectus or attollens in a rabbit, and 
felt something like disappointment on observing the eye 
remain stationary. Shortly afterwards, on looking to the 
animal while it was feeding, I saw the pupil depressed, and 
that the animal had no power of raising it. 
The explanation I conceive to be this : during the experi- 
ment the eye was spasmodically fixed by the general action 
of the muscles, and particularly by the powerful retractor, a 
muscle peculiar to quadrupeds. But on the spasm relaxing, 
and when the eye was restored to the influence of the volun- 
tary muscles, the recti, the voluntary power of raising the 
eye being lost by the division of the superior muscle, the eye 
was permanently depressed. 
II. Wishing to ascertain if the oblique muscles contract to 
force the eye-ball laterally towards the nose, I put a fine 
thread round the tendon of the superior oblique muscle of a 
rabbit, and appended a glass bead to it of a weight to draw 
out the tendon a little. On touching the eye with a feather, I 
had the pleasure of seeing the bead drawn up. And on 
repeating the experiment, the thread was forcibly drawn 
through my fingers. 
By experiments made carefully in the dead body, (having 
distended the eye-ball by dropping mercury into it to give 
it its full globular figure) I had found that the action of the 
superior oblique muscle is to turn the pupil downwards and 
outwards, and that the inferior oblique just reverses this mo- 
tion of the eye. In the above experiment there is abundance 
of proof that the superior oblique muscle acted, and yet the 
