[11] Versuch einer Theorie des Komischen (1817), s. 23.
[12] See Darwin, Expression of the Emotions, p. 199.
[13] See among other authorities, Raulin, Le Rire, p. 28.
[14] See art. “The Psychology of Tickling, Laughing and the Comic,” by G. Stanley Hall and A. Allin, American Journal of Psychology, vol. ix., p. 1 ff.
[15] Purgatorio, Canto xi., lines 82–3; cf. Canto i., line 20, where the fair planet (Venus) is said to have made the whole East laugh—a figure copied by Chaucer, The Knightes Tale, line 636. Addison touches on this poetical use of “laughter,” Spectator, No. 249.
[16] Gratiolet, De la Physionomie, p. 116. Benedick instances as interjections of laughing “ha! ha! he”! Much Ado About Nothing, IV., i.
[17] See an article on “Organic Processes and Consciousness,” by J. R. Angell and H. B. Thompson, in the Psychological Review, vol. vi., p. 55. According to these researches, a hearty laugh, causing sudden and violent changes in the breathing curve, is accompanied by the sharpest and most marked vaso-dilation, as tested by capillary pulse drawing; though in one case the opposite effect of constriction was produced.
[18] Anatomy of Melancholy, Pt. 2, sec. 2, mem. vi. subsec. 4 (“mirth and merry company”).
[19] Laughter is pronounced a “good exercise” by Dr. Leonard Hill in his useful work, Manual of Human Physiology (1899), p. 236. The physiological benefits are more fully treated of by Dr. Harry Campbell in his publication, Respiratory Exercises in the Treatment of Disease (1898), p. 125.
[20] “Positions,” ed. by Quick, pp. 64, 65.