AUDITORY APPARATUS IN MAN. 187 



siastic feelings in one, are heard and seen by another 

 with no sort of effect. It is true, however, that there is 

 a natural difference in these respects, and especially with 

 regard to music, there being some uneducated Ears 

 which are able to appreciate the finest passages in a 

 piece, though they never had heard good music before. 

 This however, is seldom the case with respect to paint- 

 ing, deep impressions and good judgment being nearly in 

 every case the result of education. 



In treating of hearing, we shall, as we have done 

 with respect to vision, begin with that structure which 

 is most highly developed, and best understood, the Hu- 

 man Ear. 



DESCRIPTION OF THE AUDITORY APPARATUS IN MAN. 



The best summary on this subject we have seen, for 

 the design of this work, is that of Mr. Roget in his 

 "Bridge water Treatise, on Animal and Vegetable Physi- 

 ology." This, therefore, will form the basis of the fol- 

 lowing treatise. 



That part of the organ of Hearing, which, above all 

 others, is essential, is the acoustic or auditory nerve, of 

 which the fibres are expanded, and spread over the sur- 

 face of a fine membrane, placed in a situation adapted 

 to receive the full impression of the sonorous undula- 

 tions which are conveyed to them. This membrane, 

 then, with its nervous filaments, which is situated within 

 the labyrinth, may be regarded as the immediate organ 

 of this sense v ; all the other parts constituting merely an 

 accessory apparatus, designed to collect and condense 

 the vibrations of the surrounding medium, and to direct 

 their concentrated action on the auditory membrane. 



The principal parts of this complicated organ are 

 exhibited in Fig. 114, as they exist in man, in their rela- 

 tive and of the natural sizes ; these parts will therefore, 

 afford a scale of real dimensions of those portions, 

 which will hereafter be explained by magnified views. 



What is it in musical tones that give pleasure 7 What is said of the 

 ear 1 Can some enjoy good music without education 1 



