IV. 



THE PHYSIOLOGY OP LAUGHTER. 



"TXT'HY do we smile when a child puts on a man's hat ? 

 VV or what induces us to laugh on reading that the 

 corpulent Gibbon was unable to rise from his knees after 

 making a tender declaration ? The usual reply to such 

 questions is, that laughter results from a perception of in- 

 congruity. Even were there not on this reply the obvious 

 criticism that laughter often occurs from extreme pleasure 

 or from mere vivacity, there would still remain the real 

 problem — How comes a sense of the incongruous to be 

 followed by these peculiar bodily actions ? Some have al- 

 leged that laughter is due to the pleasure of a relative self- 

 elevation, which we feel on seeing the humihation of others. 

 But this theory, whatever portion of truth it may contain, 

 is, in the first place, open to the fatal objection, that there 

 are various humiliations to others which produce in us any- 

 thing but laughter ; and, in the second place, it does not 

 apply to the many instances in which no one's dignity is 

 implicated : as when we laugh at a good pun. Moreover, 

 like the other, it is merely a generalization of certain con- 

 ditions to laughter ; and not an explanation of the odd 

 movements which occur under these conditions. Why, 

 when greatly delighted, or impressed with certain unex- 



