VOL. XC.] PHILOSOPHICAL TRANSACTIONS. 6^7 



for several weeks: about 12 months after the first attack, symptoms of a similar 

 kind took place in the right ear, from which also matter issued for a considerable 

 time. The discharge in each instance was thin, and extremely offensive to the 

 smell ; and, in the matter, bones or pieces of bones were observable. The im- 

 mediate consequence of these attacks was a total deafness, which continued for 3 

 months ; the hearing then began to return, and, in about 10 months from the last 

 attack, was restored to the state in which it at present remains. 



Having thus described the disease and its symptoms, he gave me the following 

 satisfactory proof of each membrana tympani being imperfect. Having filled his 

 mouth with air, he closed the nostrils, and contracted his cheeks : the air, thus 

 compressed, was heard to rush through the meatus auditorius, with a whistling 

 noise, and the hair hanging from the temples became agitated by the current of air 

 which issued from the ear. To determine this with greater precision, I called for 

 a lighted candle, which was applied in turn to each ear, and the flame was agitated 

 in a similar manner. Struck with the novelty of these phenomena, I wished to 

 have many witnesses of them, and therefore requested him, at the conclusion of the 

 lecture on the organ of hearing, to exhibit them to his fellow students ; with which 

 request he was so obliging as to comply. It was evident from these experiments, 

 that the membrana tympani of each ear was incomplete, and that the air issued from 

 the mouth, by the Eustachian tube, through an opening in that membrane, and 

 escaped by the external meatus. 



To determine the degree in which the membrana tympani had been injured, I 

 passed a probe into each ear, and found that the membrane on the left side was 

 entirely destroyed ; since the probe struck against the petrous portion of the tem- 

 poral bone, at the interior part of the tympanum, not by passing through a small 

 opening ; for, after an attentive examination, the space usually occupied by the 

 membrana tympani was found to be an aperture, without one trace of membrane 

 remaining. On the right side also, a probe could be passed into the cavity of the 

 tympanum ; but here, by conducting it along the sides of the meatus, some re- 

 mains of the circumference of the membrane could be discovered, with a circular 

 opening in its centre, about \ of an inch in diameter. From such a destruction of 

 this membrane, partial indeed in one ear, but complete in the other, it might be 

 expected that a total annihilation of the powers of the organ would have followed : 

 but the deafness was inconsiderable. This gentleman, if his attention were exerted, 

 was capable, when in company, of hearing whatever was said in the usual tone of 

 conversation; and it is worthy of remark, that he could hear with the left ear better 

 than with the right, though in the left no traces of the membrana tympani could 

 be perceived. When attending the anatomical lectures also, he could hear, even 

 at the most distant part of the theatre, every word that was delivered ; though, to 

 avoid the regular and constant exertion which it required, he preferred placing himself 

 near the lecturer. I found however, that when a note was struck on the piano- 

 forte, he could hear it only at -*-ds of the distance at which I could hear it myself; 



4 l 2 



