176 REPORT — 1861. 



greatest height ia July and August, in October diminislied, and in November dis- 

 appeared. 



On the Action of iJie EustacJilan Tube in Man, as demonstrated hi/ Dr. Politzer's 

 Otoscope. By J. Toynbee, F.li.S. 



From the time that the celebrated anatomist, Eustachius, in the 16th century, 

 discovered the tube leading from the cavity of the fauces to that of the tympanum, 

 this Eustachian tube has been usually described as constantly open, and the air in 

 the two cavities has consoquentlv been looked upon as constantly continuous. 

 Although Mr. Wharton Jones in l841, and ]SI. Ilyrtl in 1845, spolce of the faucial 

 orifico of the Eustachian tube as Laving " the property of a weak valve opening 

 either way," their opinion did not alter the views entertained by physiologists re- 

 specting the functions of the Eustachian tube, and its constantly open condition was 

 considered essential to the due performance of the function of hearing. 



In the year 1853 I laid before the Royal Society a paper, the object of which was 

 to demonstrate, _^rs%, that the faucial orifice of theEustachian tube is always closed, 

 except momentarily during the act of deglutition or when au" is forcibly blown 

 through it; secotuVy, that the Eustachian tube is opened by the muscles of the 

 palate, the tensor and levator palati; tJtirdli/, that, contrary to the preconceived 

 opinion of physiologists that " if the Eustachian tube is closed tJie hearing is lost 

 at once," in order that the function of liearing may be duly performed, it is abso- 

 lutely requisite for tlie Eustachian tube to be closed, otherwise tlie sonorous nudu- 

 lations, which ought to be confined to the tympanic cavity in order that they may 

 be concentrated upon the mcnibrana fenestra rotunda', are lost in the fauces, and tbe 

 soimds from the fauces also enter the tympanum and produce the most distressing- 

 discord. 



In proof that the faucial orifice of the Eustachian tube remains closed after the 

 act ot swallowing, the experimenter has but to swallow some saliva while the 

 nostrils are closed by the linger and thumb : a sensation of pressure is produced 

 in each ear, which disappears onlj' when the act of swallowing is again performed 

 without the pressure of tbe nose. It is also well Iniown that unless the act of de- 

 glutition be frequently practised during the descent in a diving-bell, so that the Eu- 

 stachian tube may be opened and air allowed to enter the tympanum, great deafness 

 and a feeling of pressure in the ears are produced. Further, in cases where the 

 membrana tympani is lax, it is seen to move outwards when air is blown into the 

 tympanic cavity, and it returns to its natural position only on the act of swallowing 

 being performed. 



In order to demonstrate this function of the Eustachian tube, and also to dia- 

 gnose its condition in disease, I suggested the use of an otoscope, consisting of an 

 elastic tube about eighteen inches long and a quarter of an inch in diameter, each 

 end being tipped ■with an ebony tube. Upon the introduction of one end of this tube 

 into the ear of the experimenter, while the other is placed in that of the person 

 experimented upon, it the latter distends the tympanum by a forcible attenipt at an 

 expu'ation while the nose and mouth ai'e closed, the air is heard to enter and to distend 

 the tympanum, and the cavity remains distended until the act of swallovdng ia 

 perfonned, when the diinn is heard to recede as the air makes its egress. 



The views on the physiology of the Eustachian tube advanced by me before the 

 Royal Society ha\ang attracted the attention of Dr. Politzer of Vienna, that gen- 

 tleman performed a series of experiments with the object of testing their accuracy. 

 The result is that Dr. Politzer came to the same conclusion as I had done, and he 

 invented a simple and ingenious instrument, by means of which the action of the 

 Eustachian tube can be seen. This instrument, which I have called Dr. Politzer's 

 otoscope, consists of a rounded portion of cork or India rubber, about an inch and a 

 half long, and about half an inch in diameter ; in the centre of this is a glass tube 

 about two lines in diameter, which externally is disposed in the fonn of an elbow. 

 When used, the rounded and free portion of the cork or uidia rubber is moistened, 

 and introduced into the external meatus, care being taken that it fits, so as to pre- 

 vent the outer air from passing between the instrument and the walls of the meatus. 

 When this has been accomplished, a drop of water is allowed to enter the tube so 

 as to fill half the elbow, and to be on the same plane in each portion of it. The 



