A good, real, unrestrained, hearty laugh is a sort of glorified internal massage, performed rapidly and automatically. It manipulates and revitalizes corners and unexplored crannies of the system that are unresponsive to most other exercise methods. – Author unknown, from an editorial in New-York Tribune, quoted in Quotations for

For one seldom hears a genuine laugh nowadays, and much of the phraseology of laughter is a mere fashion of speech. There are many people whose sides have never ached from over-indulgence in the outward expression of mirth…. With some persons a wheeze or a chuckle is the utmost they can compass. – “Laughter,” in The Spectator for the week ending Saturday, January 19, 1889