100 HABIT AND INTELLICxENCE. [chap. 



Sight gives think it is demonstrable that tlie first cognition of space is 

 of^pac'r o'btained, not by sight, but by touch. 



Characters Sight is a highly intellectual sense ; and in connexion 

 of sight, ^-^.i^ ^jj-g ^g ^i^g £^g^^ ^YiQ^ impressions of sight are capable 



of being not only remembered, but reproduced in memory, 

 or recollected, with great vividness. 



Of 5. Tlie nerves of hearing are not nerves of any other sense. 



hearing. Hearing, like sight, is a highly intellectual sense ; and 

 impressions of sound, such as those of voices or of music, 

 are capable of beiiig reproduced in memory with great 

 •\T.vidness. Hearing gives no cognition of space in the 

 sense of extension, but it does give a cognition of direc- 

 tion : all the higher animals, at least, appear to have some 



Semi- power of judging from what direction a sound comes. " It 



circular jg commonly supposed that the ' semicircular canals ' have 



canals give ,.„ . . -, . 



a sense for their peculiar function to receive the impressions by 

 °S ^^f. which we distinguish the direction of sounds ; and it is 



direction ° 



of sounds, certainly a powerful argument in support of this view that 



in almost every instance in which these parts exist at all, 



they hold the same relative positions as in man, their three 



planes being nearly at right angles to one another." ^ This 



power of judging of the direction of sound, however, is 



very deficient in precision ; and without the assistance 



of other senses it would probably be quite insufficient to 



give rise to any cognition of space, at least unless it was 



incomparably more accurate than it is in man. 



Heiiringis That ill which hearing differs from all the other senses 



nt'ii''^ ^^^ i'^ ^^^ ^'^^^> ^^^^^ distinct sounds falling on the ear together 



R"iises, in ^q not neccssarily combine into a resultant sensation, as 



ofdiscri- tastes, smells, and colours do when they are mixed. Unlike 



minating those Other sensations, simidtaneous sounds are capable 



SllllUl- . . ^ 



Ta neons of being recognised as distinct, and of being attended to 

 soiinrs. separately. There is good reason to believe that this 

 remarkable property of the sense of hearing depends on 

 the peculiar manner in which the nerves of hearing termi- 

 nate in the ear. The nerves of the other organs of sense 

 T^. . ., branch out and form a network at their terminations : thus 



Distnbu- 



tijii of the the nerves of touch, of taste, and of smell form extended 



^ Carjientei's Human Physiology, j). 669. 



