196 THE PHYSIOLOGY OF LAUGHTEE. 



nervous system in general discharges itself on the muscular 

 system in general : either with or without the guidance of 

 the will. The shivering j^roduced by cold, implies irregular 

 muscular contractions, which, though at first only partly 

 involuntary, become, when the cold is extreme, almost 

 wholly involuntary. When you have severely burnt your 

 finger, it is very difficult to preserve a dignified composure : 

 contortion of face, or movement of limb, is pretty sure to 

 follow. If a man receives good news with neither change 

 of feature nor bodily motion, it is inferred that he is not 

 much pleased, or that he has extraordinary self-control — 

 either inference implying that joy almost universally pro- 

 duces contraction of the muscles; and so, alters the ex- 

 pression, or attitude, or both. And when we hear of the 

 feats of strength which men have performed when their 

 lives were at stake — when we read how, in the energy of 

 despair, even paralytic patients have regained for a time 

 the use of their limbs ; we see still more clearly the rela- 

 tions between nervous and muscular excitements. It be- 

 comes manifest both that emotions and sensations tend to 

 generate bodily movements, and that the movements are 

 vehement in proportion as the emotions or sensations are 

 intense.* 



This, however, is not the sole direction in which ner- 

 vous excitement expends itself. Viscera as well as muscles 

 may receive the discharge. That the heart and blood- 

 vessels (which, indeed, being all contractile, may in a re- 

 stricted sense be classed with the muscular system). are 

 quickly aifected by pleasures and pains, we have daily 

 proved to us. Every sensation of any acuteness acceler- 

 ates the pulse ; and how sensitive the heart is to emotions, 

 is testified by the familiar expressions which use heart and 



* For numerous illustrations see essay on " The Origin and Function 

 of Music." 



