CANTO ir. REPRODUCTION OF LIFE. 77 



* To secret shades, ye Virgin trains, retire, 

 ' And in your bosoms guard the vestal fire." 

 The obedient Beauties hear her words, advised, 

 And bow with laugh repress'd, and smile chastised. 



Now at her nod the Nymphs attendant bring 

 Translucent water from the bubbling spring; 



With laugh repressed. 1. 434. The cause of the violent actions of 

 laughter, and of the difficulty of restraining them, is a curious subject 

 of inquiry. When pain afflicts us, which we cannot avoid, we learn 

 to relieve it by great voluntary exertions, as in grinning, holding 

 the breath, or screaming; now the pleasurable sensation, which ex- 

 cites laughter, arises for a time so high as to change its name, and 

 become a painful one; and we excite the convulsive motions of the 

 respiratory muscles to relieve this pain. We are however unwilling 

 to lose the pleasure, and presently put a stop to this exertion ; and 

 immediately the pleasure recurs, and again as instantly rises into pain. 

 Which is further explained in Zoonomia, Sect. 34. 1. 4. When this 

 pleasurable sensation rises into a painful one, and the customs of so- 

 ciety will not permit us to laugh aloud, some other violent voluntary 

 exertion is used instead of it to alleviate the pain. 



With smile chastised. 1.434. The origin of the smile has generally 

 been ascribed to inexplicable instinct, but may be deduced from our 

 early associations of actions and ideas. In the act of sucking, the lips 

 of the infant are closed round the nipple of its mother, till it has 

 filled its stomach, and the pleasure of digesting this grateful food suc- 

 ceeds; then the sphincter of the mouth, fatigued by the continued 

 action of sucking, is relaxed; and the antagonist muscles of the face 

 gently acting, produce the smile of pleasure, which is thus during 

 our lives associated with gentle pleasure, which is further explained 

 in Zoonomia, Sect. 16. 8. 4. 



