98 LOCALIZED ELECTRIZATION. 



by the pharyngeal rheophore ; and to the crico-thyroid ® by the 

 moist external rheophore. 



Indirect faradization of the larynx is still more simple. By 

 directing the extremity of the pharyngeal rheophore to the lateral 

 portions of the inferior constrictor, we act upon the inferior laryn- 

 geal nerve, which supplies all the internal muscles of the larynx. 

 The left inferior laryngeal may also be reached through the 

 cesophagus. 



My experience has shown that the above procedure would 

 frequently be very advantageous in aphonia due to paralysis of 

 the muscles of the larynx. I shall record, in the sequel, many 

 cases in which I have practised the operation with success. 



[Duchenne makes no reference to the use of the laryngoscope to facilitate 

 direct faradization, or galvanization, of the muscles of the larynx. It is 

 probable that his experience has shown that the intervention of the laryngo- 

 scope is practically rarely necessary. Precision of manipulation, however, 

 is at all times to be cultivated, and this is only ]iossible of the larynx by the 

 aid of the laryngoscope. Ziemssen has treated the subject of laryngeal elec- 

 trization with great perspicuity in liis work Die Elertricitdt in der Medizin, 

 and I append a translation of his observations which I have no doubt will 

 prove acceptable to the English practitioner. — //. T. 



ZIEMSSEN ON LARYNGEAL ELECTRIZATION. 



" The electric excitation of the nerves and muscles of the larynx has latterly 

 become of great practical importance ; on account of the increasing certainty 

 of laryngoscopic diagnosis, and especially on account of the evidence thus 

 obtained of tlie frequency of paralytic conditions of the laryngeal muscles, 

 atfecting them either singly or in groups. 



" Much laboiir has been bestowed in recent years ujion endeavoiirs to find a 

 satisfactory basis for electrical treatment of the larynx. The first attempts 

 were to find the laryngeal branches of the vagus nerve in the neck, and to 

 excite them through the soft jiarts superficial to them. Tliese attempts, 

 made upon patients suffering from some disorder of the nerves or muscles of 

 the larynx, were sometimes followed by beneficial therai^eutical results ; and 

 it was thence inferred that the excitation of the nerves in question had been 

 accomplished. This conclusion, I believe, was not justified ; and it has still 

 to be proved, notwithstanding the admitted recoveries, that it is generally 

 possible to direct an electric current upon the superior and inferior laryngeal 

 nerves through the skin. Gerhardt has been at the pains to test the effect of 

 the excitation in the only practicable way, by means of the laryngeal mirror, 

 and he obtained only negative or doubtful results. He found, in healthy 

 persons, on ap]:)lying the induced current to the regions of the neck that are 

 superficial to the course of the recurrent nerves, — namely, for the superior 

 laryngeal nerves to the vicinity of the superior cornua, for the recurrent 

 nerves to the inferior cornua of the thyroid cartilage, — that he i^rodixced 

 neither closure of the glottis, nor tension nor vibration of the vocal cords, nor 

 audible change of tone. He observed, on the contrary, after excitation on 

 both sides, a tremulous falling apart of the vocal cords after the utterance of 

 vocal sounds : the glottis in one case attaining one-half, in another three- 

 fourths of its normal inspiration width. After excitation on one side, he 

 observed a similar effect on the vocal cord of that side only. 



* .'M. Lorget has shown, by direct and I crico-thyroid performs an important part 

 well-conceived experiments, that the ( in the act of phonation. 



