PERSONAL APPEARANCES IN HEALTH AND DISEASE. 19 



no longer restrained by the passive counteraction of its 

 " extensor " muscles. It may be mentioned in passing, 

 that so little is there any effort required to maintain the 

 body erect, that it is a sign rather of weakness than 

 strength in anyone who exercises an effort to do this. 

 This may seem paradoxical, but it is nevertheless the 

 case; and he who walks "bolt upright" with his chin 

 in the air and his back as rigid as a plank, is often 

 not a strong, but a weak man. 



In consequence of this it happens that various de- 

 formities arise from the equilibrium between opposing 

 muscles being destroyed from weakness or palsy of the 

 one set, or by the over-action of the other set. For 

 instance u wry-neck," which consists in the head being 

 permanently fixed in a position inclined to one shoulder^ 

 or its continual spasmodic movement in that one di- 

 rection, is due to the contraction, or over-action of the 

 muscle causing that movement not being balanced by its 

 opponent ; or if the muscles of expression, those of the 

 face, be palsied on one side, the mouth appears drawn 

 up and out to the opposite side, an appearance exag- 

 gerated by calling the muscles into action as in laughing; 

 or, again, in " squinting," we have an example of weak- 

 ness or palsy of one or more of the six small muscles 

 moving the eye-ball preventing the movement of the eye 

 in their direction of action, so that the two eyes no 



