()28 PHILOSOPHICAL TRANSACTIONS. [ANNO 1800. 



and he informed me, that in a voyage to the East Indies, while others, when ships 

 were hailed at sea, could catch words with accuracy, his organ of hearing received 

 only an indistinct impression. But the most extraordinary circumstance in this 

 case is, that the ear was nicely susceptible of musical tones ; for he played well on 

 the flute, and had frequently borne a part in a concert. I speak this from the 

 authority of his father, who is a judge of music, and plays well on the violin : he 

 told me, that his son, besides playing on the flute, sung with taste, perfectly in 

 tune. 



The slight degree of deafness of which Mr. P complained, was always 



greatly increased by his catching cold : an effect which seems to have arisen from 

 the meatus being closed by an accumulation of the natural secretion of the ear ; for 

 it frequently happened to him, after he had been some time deaf from cold, that a 

 large piece of hardened wax, during a fit of coughing, was forced from the ear, by 

 the air rushing from the mouth through the Eustachian tube, and his hearing was 

 instantly restored. From bathing too, he suffered inconvenience, unless his ears 

 were guarded against the water, by cotton being previously forced into the meatus. 

 When this precaution was neglected, the water, as he plunged in, by rushing into 

 the interior parts of the ears, occasioned violent pain, and brought on a deafness, 

 which continued till the cause was removed, that is, till the water was discharged : 

 but he had acquired the habit of removing it, by forcing air from the mouth through 

 the ear. 



In a healthy ear, when the meatus auditorius is stopped by the finger, or is 

 otherwise closed, a noise similar to that of a distant roaring of the sea is produced : 

 this arises from the air in the meatus being compressed on the membrana tympani. 

 In the case here described, no such sensation was produced : for, in Mr. P.'s ear, 

 the air, meeting with no impediment, could suffer no compression; since it found 

 a passage, through the open membrane, to the mouth, by means of the Eustachian 



tube. Mr. P was liable to the sensation commonly called the teeth being on 



edge, in the same degree as it exists in others ; and it was produced by similar acute 

 sounds, as by the filing of a saw, the rubbing of silk, &c. Its occurring in him 

 seems to disprove the idea which has been entertained of its cause ; for it has been 

 thought, that the close connection of the nerve called the chorda tympani with the 

 membrana tympani, exposed it to be affected by the motions of the malleus ; and 

 that, as it passes to nerves connected with the teeth, they would suffer from the 

 vibratory state of the nerve, produced by the agitations of the membrane. But in 

 this case, as the membrane was destroyed on that side on which the sensation was 

 produced, some other explanation must be resorted to ; and 1 see no reason why 

 this effect should not be referred to that part of the auditory nerve which lines the 

 labyrinth of the ear, which, being impressed by acute and disagreeable sounds, 

 would convey the impression to the portio dura of the same nerve, and to the teeth 

 with which that nerve is connected. The external ear, though 2 distinct muscles 

 are inserted into it, is capable, in its natural state, of little motion ; however, when 



