ACUTENESS AND DELICACY OF HEARING. 197 



menon of hearing may be displayed, the sonorous waves 

 must move through the windings of the labyrinth with the 

 same facility that they traverse space; the rush of meteors, 

 and the immeasurable voices which nature has given to the 

 atmosphere, to the ocean, and to mountains, must be trans- 

 mitted to our ears in their relative proportions, as well as 

 the sound of a falling dew-drop. How can the ear in its 

 infinitesimal proportions perceive with equal precision the 

 sound of the gigantic instruments which vibrate under the 

 hand of nature, and the feeblest noise which traverses the 

 air? 



Let us remember that if we get a glimpse of the details 

 of natural phenomena, and of those movements which con- 

 stitute life, it is not in considering them as a whole, but in 

 analyzing them as far as our limited means will permit. In 

 the vibrations of the globe of air which surrounds our planet, 

 as in the undulations of the ether which fills the immensity 

 of space, it is always by molecules which are intangible for us, 

 put in motion by nature, always by the infinitely little, that 

 she acts in exciting the organs of sense, and she has modelled 

 these organs in a proportion which enables them to partake 

 in the movement which she impresses upon the universe. 

 She can paint with equal facility on a fraction of a line of 

 space on the retina, the grandest landscape or the nervelets 

 of a rose-leaf; the celestial vault on which Sirius is but a 

 luminous point, or the sparkling dust of a butterfly's wing : 

 the roar of the tempest, the roll of thunder, the echo of an 

 avalanche, find equal place in the labyrinth whose almost 

 imperceptible cavities seem destined to receive only the 

 most delicate sounds. 



Acnteness and delicacy of hearing. It has been said that 

 hearing is the most perfect of the senses in man. Considered 

 as a musical instrument the ear is in fact a most admirable 

 organ, and which man alone possesses; but here, as in the 

 eye, we must distinguish between the apparatus of hearing 

 and what pertains to the domain of the mind. The ear 

 perceives sounds, but the mind estimates their regularity, 

 measures their intervals, judges them melodious or the re- 

 verse, determines their discord or their harmony. If the 



