AUDITORY NEBVES. 149 



torn." ' Analogous observations have been made by Valen- 

 tin * and by Schiff ; 8 but, in opposition to these, is a state- 

 ment by Brown-Sequard, that the degree of pain produced 

 by excitation of the auditory nerve " appears to be as con- 

 siderable as that caused by a similar excitation of the tri- 

 geminal nerve." * This bare assertion, however, we can 

 hardly accept in opposition to the clear results of previous 

 experiments and the analogy with observations upon the other 

 nerves of special sense. 



The phenomena observed during the passage of galvanic 

 currents through the auditory nerves have, of late years, 

 been the subject of much discussion. The old experiment 

 of Yolta, 6 which was almost immediately confirmed by Bit- 

 ter," is sufficiently familiar, and is often quoted as showing 

 that galvanic stimulation of these nerves produces a sensa- 

 tion of sound ; but the facts ascertained leave room for 

 doubt with regard to the precise mode of action of the cur- 

 rent. A careful study of recent observations on this point 

 renders the question even more obscure ; but, from a purely 

 physiological point of view, we have only to do with the 

 effects of stimulating the auditory nerves in health. Leav- 

 ing the therapeutic and diagnostic uses of galvanism out of 

 the question, we find that there is considerable uncertainty 

 with regard to the fact of direct stimulation of the auditory 

 nerves, in the recent experiments with the galvanic current. 

 Brenner observed strong sensations of sound with one of the 

 poles of a battery in the auditory passage filled with water 



1 MAGEXDIE, Suite des experiences sur les fonctions de la cinquieme paire de 

 nerfs. Journal de physiologic, Paris, 1824, tome iv., p. 314. 



2 VALENTIN, Lehrbuch der Physiologic, Braunschweig, 1844, Bd. ii., S. 678. 

 3 SCHIFF, Lchrbuch der Physiologic, Lahr, 1858-'59, Bd. i., S. 399. 



4 BROWX-SEQUARD, Experimental Researches applied to Physiology and Pathol- 

 ogy, New York, 1853, p. 100. 



6 VOLTA, On the Electricity excited by the mere Contact of conducting Sub- 

 stances of different kinds. Philosophical Transactions, London, 1800, p. 427. 



6 HITTER, Versuche und Bemerkungen uber den Galvanismus der Voltaischen 

 Batterie.Annalen der Physik, Halle, 1801, Bd. vii., S. 463, et seq. 



