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XV. On the motions of the Eye , in illustration of the uses of 
the muscles and nerves of the orbit. By Charles Bell, Esq. 
Communicated by Sir Humphry Davy, Bart. P. R. S. 
Read March 20, 1823. 
The object of this paper is to explain the reason of there 
being six nerves distributed to the eye, and consequently 
crowded into the narrow space of the orbit. 
But before it is possible to assign the uses of these nerves, 
we must examine the motions of the eye more minutely than 
has hitherto been done, and try to comprehend the offices to 
be performed. Much as the eye has been studied, the frame- 
work which suspends it, and by which it is moved and pro- 
tected, has not received the attention it deserves. Yet this 
frame-work, or apparatuses not less calculated to renew our 
wonder, than the properties of the organ itself. 
It is therefore necessary to divide the paper into two parts. 
First , to show the uses of the apparatus which is exterior to 
the eye-ball ; and then, in the second place , to consider how 
the nerves minister to these offices. 
Part I. 
Of the muscles and frame-work which are around the eye-ball. 
Even grave and learned men have eulogized this organ as 
the most necessary to intellectual enjoyment, and which ranges 
from the observation of the fixed stars, to that of the expres- 
