on the Structure, Distribution, and Functions of the Nerves. 49 



slight palsy of the muscles on one side of the face, and which 

 the physician knows is not formidable. Inflammations of glands 

 seated behind the angle of the jaw will sometimes produce 

 this. All such affections of the respiratory nerve will now be 

 more easily detected; the patient has a command over the 

 muscles of the face, he can close the lips, and the features 

 are duly balanced ; but the slightest smile is immediately at- 

 tended with distortion, and in laughing and crying the para- 

 lysis becomes quite distinct. 



" The knowledge of the sources of expression teaches us 

 to be more minute observers. The author had lately to watch 

 the breathing of an infant which had been several times re- 

 stored from a state of insensibility. At length the general 

 powers fell low without any returning fit; insensibility and 

 loss of motion stole over the frame ; all but the actions ex- 

 cited by the respiratory nerves ceased; then each act of re- 

 spiration was attended with a twitching of the muscles of the 

 ala nasi, and of that muscle of the cheek which makes the 

 dimple in smiling. It was then evident that the child could 

 not recover ; that all but the system of respiratory nerves had 

 lost their powers ; that the features, as far as they were subject 

 to the influence of the other nerves, had fallen. 



" There are conditions of the lungs, when the patient is in 

 great danger, and yet the inflammation is not marked by the 

 usual signs of pain and difficult motions of the chest. We 

 shall see nothing but the twitching of those muscles of the 

 face, which are animated by the respiratory nerve. We see 

 a certain unusual dilatation of the nostrils, and a constrained 

 motion of the lips, which with the change of voice is just suf- 

 ficient to give alarm, and indicate the patient's condition. 

 This is a state of the lungs very often produced after severe 

 accidents, as gun-shot wounds, and after great surgical opera- 

 tions. 



" These circumstances are stated to prove that the subject 

 of expression is not foreign to medical studies; and certainly, 

 by attention to the action of the muscles of the face, we shall 

 find the views drawn here from the anatomy, further coun- 

 tenanced. We learn that smiling is an affection of the nerve of 

 respiration on the muscles of the face, and that when laughter 

 shakes the sides, it is only an extended and more convulsive 

 action of the muscles produced by the same class of nerves. 

 When to the paleness and coldness and inanimation of grief, 

 there is added the convulsive sob and the catching of the throat, 

 and the twitching of the lips and nostrils, we discover the same 

 class of nerves to be affected, which, in Crying, are only more 

 obviously in operation, producing more violent contractions. 



Vol. G4. No. 3 1 5. .////// 1 824. (3 " In 



