VOL. XC.] PHILOSOPHICAL TRANSACTIONS. 573 



concert, though he had never learned music, was suddenly seized with a giddiness 

 in the head, and a slight degree of numbness in the right side and arm. These 

 feelings went off* in a few hours, but on the 3d day returned, and for several weeks 

 he had returns of the same sensations. It was soon discovered that he had lost his 

 musical ear; he could neither sing a note in tune, nor in the smallest degree per- 

 ceive harmony in the performance of others. For some time he himself thought 

 he had become a little deaf, but his medical attendant was not sensible of that in 

 conversation. On going into the country, he derived great benefit from exercise 

 and sea-bathing. Twenty months after the first attack, he was capable of singing 

 a Scotch air with tolerable exactness, though he could not sing in concert. He 

 continued to improve in his health, and in the course of 2 or 3 years completely 

 recovered his ear for music. In this case, there appeared to be some affection of 

 the brain, which had diminished the actions of the tensor muscles of the mem- 

 branse tympani, through the medium of the nerves which regulate their actions; 

 this gradually went off, and the muscles recovered their former action. 



Case 2. A young lady was seized with a frenzy, which lasted for several years. 

 Previous to her derangement, she was incapable of singing in tune, from the 

 want of an ear for music; but in the course of her madness she frequently, to the 

 astonishment of her relations, sung a tune with tolerable correctness. This case 

 is the reverse of the former; and, as it arose from a directly contrary affection of 

 the brain, may be considered as the result of an unusual degree of action in the 

 tensor muscles, giving the membrane a more correct adjustment than it had before. 



Case 3. An eminent music master, after catching cold, found a confusion of 

 sounds in his ears. On strict attention he discovered, that the pitch of 1 ear was 

 4- a note lower than that of the other; and that the perception of a simple sound 

 did not reach both ears at the same instant, but seemed as 2 distinct sounds, fol- 

 lowing each other in quick succession, the last being the lower and weaker. This 

 complaint distressed him for a long time, but he recovered from it without any 

 medical aid. In this case, the whole defect appears to have been in the action of 

 the radiated muscle, exerted neither with the same quickness nor force in J ear as 

 in the other, so that the sound was half a note too low, as well as later in being 

 impressed on the organ. This affection of the muscle of the membrana tympani 

 is very similar to an affection of the straight muscles of one of the eyes, produ- 

 cing double vision, which I have noticed in a former lecture, when treating of the 

 wrong actions of that organ*, 



In endeavouring to explain the uses of the more internal parts of the ear, con- 

 siderable advantage may be derived from classing them in 2 divisions; namely, 

 those which are formed for the purpose of receiving impressions conveyed through 

 the medium of liquid or of solid substances; and those adapted to receive im- 

 pressions made by the impulses of an elastic fluid, as the common air. This can 

 be done correctly. Fish, which are formed to hear in water, can have only the 



* Vide Phil. Trans, for 1797-— Orig. 



