150 SPECIAL SENSES. 



and the other connected with different parts of the body. 1 

 When the cathode was placed in the ear, the sound was heard 

 at the making of the current. With the anode in the ear, 

 there was no sound at the making of the current or during 

 its passage, but a slight sound was heard at the breaking of 

 the current. These phenomena closely resemble those pro- 

 duced by the galvanic current applied to ordinary motor 

 nerves, in so far as the action seemed to be most vigorous at 

 the making of the circuit, with the direct current, and at 

 the breaking of the circuit, with the inverse current ; for, 

 when the cathode is placed in the ear, the current is direct, 

 following the course of the nerve from the centre to the 

 periphery, and vice versa. In view of the fact that some 

 writers attribute the subjective auditory phenomena ob- 

 served by Brenner to stimulation of branches of the facial, 

 and, through this nerve, to the action of the muscles of the 

 middle ear, it is interesting, in this connection, to refer to 

 the experiments of Chauveau upon the action of the direct 

 and the inverse current upon the facial. 2 Without following 

 out the discussion of this question in detail, it seems only 

 necessary to study the very clear and satisfactory experiments 

 of Wreden, to become convinced that the subjective auditory 

 phenomena, attributed by Brenner and others to irritation of 

 the auditory nerves, are due to contraction of the muscles of 

 the middle ear, particularly the stapedius. The facts, clinical 

 and experimental, upon which this view is based, are the fol- 

 lowing : In cases of clonic spasm of the stapedius, sensations 

 of sound have been observed, exactly like those produced by 

 an induced current. In cases of complete facial paralysis from 

 otitis, in which paralysis of the auditory nerve could be posi- 

 tively excluded, it was not possible to produce subjective au- 

 ditory sensations, even by powerful galvanization by a cathe- 



1 BRENNER, Zur Elektrophysiologie und Elektropatlwlogie des Nervus acusticus. 

 St. Pctersburger medidnische Zeitschrift, St. Petersburg, 1863, Bd. iv., S. 286, 



et seq. 



2 See vol. iv., Nervous System, p. 110. 



