PARALLEL BETWEEN THE EAR AND EYE. 2OI 



abnormal conditions into which we shall not inquire; and 

 of which the mechanism is obscure or unknown. A pro- 

 longed shock to the auditory nerve by a loud sound or noise 

 will cause a persistent confused sensation, which is felt by 

 everyone after a long journey by railway, or after being near 

 a great waterfall or in a mill for a length of time. 



Parallel between the ear and the eye. The eye and the ear 

 present many analogies, both in regard to their functions 

 and their anatomy. The pavilion of the ear has been com- 

 pared to the eyelids, the auditory canal to the anterior 

 chamber of the eye, the tympanum to the iris, the cavity of 

 the tympanum to the posterior chamber, the small bones to 

 the crystalline, and the liquor Cotunnii to the vitreous body. 

 These organs differ in their nature, like the exciting agents 

 which pass through them. Sound and light both originate 

 in vibrations, but transparency is the essential condition of 

 the organ through which light passes, while sounds are pro- 

 pagated through all bodies, solid, fluid, or gaseous. 



The sense of light enables man to contemplate the admir- 

 able spectacle of the universe, but for the eye nature is 

 mute ; to it motion alone denotes life ; hearing completes 

 our impressions, everything is animated by it, and man takes 

 part in the life of the external world, and shares the thoughts 

 of his fellows. The perfection of these two senses enables 

 us the better to appreciate the connection between the 

 functions, and the unity of our organs. The sight speaks 

 more directly to the intelligence, it enlarges the field of 

 thought, it gives birth to precise notions of light, of form, 

 of extent; and it permits the communication of thought by 

 conventional signs. Hearing is a necessary condition of 

 articulate language ; without it man lives alone, affection and 

 confidence lose their most precious forms of expression, and 

 friendship cannot exist. 



Auditory sensations act upon the nervous system with 

 more force than visual sensations. We are carried away by 

 rhythm, or it adapts itself to our ideas and our passions; 

 music plunges us into an ideal world, and holds us by an in- 

 definable charm; in a word, if sight speaks more especially 

 to the intellect, hearing addresses itself to the affections. 



