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nerves of the orbit of the eye. 
forehead and eyelids. If this small nerve be divided, then 
the motions of the eyelids are lost, and they remain open. 
The inquiries instituted in the first part of this paper, give 
a lively idea of the consequences of this imperfection ; show- 
ing that the eye being unguarded and unwashed, becomes 
dry by evaporation and inflames, and the cornea becomes 
opaque. It is unnecessary to point out the importance of 
this fact to the operating surgeon. 
It has been asked, why should this nerve be called respi- 
ratory ; and what have the actions of respiration to do with 
the eye-lids ? The name was given to excite attention to 
certain relations ; that the question might be asked, and the 
connections of remote parts noticed and remembered. These 
connections of remote parts are so curious, the knowledge of 
them is sometimes so useful, and they are so immediately 
related to the present subject, that I may be permitted to 
explain them. 
During the state of excitement of the respiratory organs, 
a very extensive consent of the muscular frame is necessary 
to bind together and support the textures, that they may 
bear the strain either during violent efforts of the body, or 
in coughing, sneezing, &c. We may take the act of sfteezing, 
as a familiar example of the manner in which the eye is 
guarded during a sudden and violent act of expiration. 
At the instant of this convulsive action of the respiratory 
muscles, a violent impulse is communicated to the head along 
the column of blood in the vessels of the head and neck. 
Every body is sensible of the eye flashing light, but the 
cause is mistaken ; for it is supposed to be the impulse of 
blood forced into the eye ; whereas it is the contraction of 
