422 THE BODY AT WORK 



tone, without any alteration in their number or their loudness, 

 makes a change in its acoustic quality. Any attempt to corre- 

 late physical changes the movements of air in the outer ear 

 with the effects which they may be supposed to have upon 

 the organ of Corti must take into account this wide range of 

 variation of wave-form. We have called attention to the diffi- 

 culties which it introduces ; but have no hope of indicating the 

 way in which they may be overcome. 



Nothing connected with the physiology of the sense of hear- 

 ing is more remarkable than its capacity for education. The 

 cochlea of one human being is as extensive and as elaborate in 

 structure as that of another, yet some men can make an 

 infinitely more refined use of it as an analytical apparatus than 

 can others. A native of the Torres Straits cannot distinguish 

 as two separate notes sounds which are less than a semitone 

 apart. Sir Michael Costa could distinguish sounds into the 

 sixty-fourth parts of semitones. The cochlea of a cat is not 

 less elaborate than that of a man, yet Man's mental life is 

 based upon the analysis of auditory sensations. His supreme 

 advance in the animal scale has depended upon the invention 

 of language, by means of which he communicates and receives 

 information, thus rendering experience eternal, notwithstand- 

 ing the transience of the individuals who acquire and transmit 

 it. An animal is born, finds out, dies. A man starts with the 

 wisdom of the race beneath his feet. 



Hearing has a nebulous origin in sensations of movement or 

 displacement. The connection between the two special senses 

 the sense of orientation and the sense of hearing, properly 

 so-called remains always intimate. David danced before the 

 Ark of the Lord. All people, savage and civilized, associate 

 music with movement. High in the animal scale appears the 

 sense-organ which enables its possessor to discriminate musical 

 tones. By its use Man has developed with great rapidity as 

 secular time is reckoned an intelligence which removes him 

 from all other animals a planet's space. The sounding of his 

 organ of Corti by pure tones and combinations of pure tones 

 gives him extreme pleasure, although it in no way ministers 

 to his intelligence. Yet there is in the enjoyment of music a 

 quality of pleasure which makes it near akin to the satisfac- 

 tion which we experience in exercising the intellect. 



