198 SENSE OF HEARING. 



Mussey, 1 of Cincinnati, which shows, that other nerves besides the 

 portio mollis of the seventh pair may, under unusual circumstances, be 

 inservient to audition. In this case there was no appearance of meatus 

 auditorius externus in either ear, and yet the man, twenty-seven years 

 of age, although his sense of hearing was too obtuse for low conversa- 

 tion, could hear sufficiently well to prosecute his business that of a 

 bookseller without material inconvenience. By covering the head 

 with layers of cloth, the hearing was manifestly obscured. On speak- 

 ing to him with one end of a stick in the speaker's mouth, whilst the 

 other end was applied in succession to different parts of the head and 

 face, it was found, that the part over the mastoid process conducted 

 sound most readily; and that the parts corresponding with the upper 

 two-thirds of the occipital, the mastoid plate of the temporal, and the 

 posterior half of the parietal bone, transmitted sounds more readily than 

 the anterior half of the scalp, the forehead, temples, or any other part 

 of the face. Professor Mussey infers, from the results of his observa- 

 tions on this case, that the nerves, derived from the spinal cord below 

 the foramen magnum of the occipital bone, and reflected in profusion 

 over the scalp, were concerned in this unusual function, and that the 

 branches of the fifth nerves were probably the seat of the peculiar 

 faculty on the face. 2 A case also was communicated to the author by 

 the Rev. Dr. Parker, of Macao, in which there was no evidence of ex- 

 ternal ear. The hearing was very indistinct. Under the idea, that the 

 internal organs were perfect, and that, to render the hearing so, it was 

 only necessary to perforate the integument so as to admit the air to the 

 tympanum, Dr. Parker, at the request of the youth and his parents, 

 determined to perforate one ear. In accordance with Chinese prejudice 

 in favour of the cautery, caustic potassa was applied, and " as soon as 

 the slough from the first applications was removed, the hearing was 

 surprisingly improved." No cavity, however, could be discovered. 

 After different operations, he was able to hear a whisper. 3 



The immediate function of the sense of hearing is to appreciate 

 sound; and we may apply to it what has been said of the other senses; 

 that, in this respect, it cannot be supplied by any other; is instinctive;' 

 requires no education; and is exerted as soon as the parts have attained 

 a due degree of development. 



Amongst the advantages afforded by the possession of this sense, 

 which has been well termed intellectual, are two of the highest gratifi- 

 cations we enjoy, the appreciation of music, and the pleasures of con- 

 versation. To it we are indirectly indebted for the use of verbal lan- 

 guage the happiest of all inventions as it has been properly termed; 

 and to which we shall have to advert in the course of our inquiry into 

 the animal functions. 



Metaphysicians and physiologists have differed widely in their views 

 regarding the organs more immediately concerned in the appreciations 

 in question. Many, for example, have referred the faculty of music to 

 the ear; and hence, in common language, we speak of an individual, 



1 American Journal of the Medical Sciences, Feb., 1838, p. 378. 



3 A similar case by Mr. Swan is in Medico-Chirurgical Transactions, vol. xi. 



3 First JReport of the Ophthalmic Hospital, Canton, Feb., 1826. 



