MEMBRANA TYMPANI. 205 



isolation of function in different parts, which is so seductive 

 to physiologists, there are certain facts and considerations 

 which prevent us from adopting it absolutely and exclusively 

 as an explanation of the mechanism of the appreciation of 

 musical sounds. These are the following : 



Destruction of both membranse tympani does not neces- 

 sarily produce total deafness, although this condition involves 

 considerable impairment of hearing. So long as there is simple 

 destruction of these membranes, the bones of the middle ear 

 and the other parts of the auditory apparatus being intact, 

 the waves of sound are conducted to the auditory nerves, 

 though imperfectly. In a remarkable case reported by Sir 

 Astley Cooper, which is cited by most writers on physiology, 

 one membrana tympani was entirely destroyed, and the other 

 was nearly gone, there being some parts of its periphery re- 

 maining. In this person, the hearing was somewhat im- 

 paired, though he could distinguish ordinary conversation 

 pretty well. Fortunately he had considerable musical taste, 

 and it was ascertained that his musical ear was not seriously 

 impaired ; " for he played well on the flute and had frequently 

 borne a part in a concert. I speak this, not from his author- 

 ity only, but also from that of his father, who is an excellent 

 judge of music, and plays well on the violin : he told me, 

 that his son, besides playing on the flute, sung with much 

 taste, and perfectly in tune." 1 This single case, if its details 

 be accurate which we have no reason to doubt shows con- 

 clusively that the correct appreciation of musical sounds may 

 exist independently of the action of the membrana tympani. 



There is now one consideration, of the greatest impor- 

 tance, that must be kept in view in studying the functions of 



reasons that the theory has received so little consideration by later writers. It is 

 interesting, however, to note several cases reported by Home, in which the cor- 

 rect appreciation of musical sounds was temporarily lost, in some cases, as the 

 result of a nervous affection, and in others, from catarrh. 



1 COOPER, Observations on the E/ects which take place from the Destruction of 

 the Membrana Tympani of the Ear. In a Letter to EVERARD HOME. Philo- 

 sophical Transactions, London, 1800, p. 155. 



