100 LOCALIZED ELECTRIZATION. 



internal application, especially because of the irritability of the nracons 

 membrane of the month and larynx. The last-named author plainly declares 

 the direct excitation of the laryngeal muscles to be ' unnecessary.' 



" During several years that I have studied this question, I have applied 

 myself, first, to perfect the method of application upon a number of persons 

 habituated to the process, and, next, to demonstrate its utility and thera- 

 peutical value in suitable cases. On the second question I have spoken else- 

 where ; '^ and here I confine myself to the first. 



" The direct electric excitation of the laryngeal muscles from the pharynx, 

 which in all other cases T prefer to the percutaneous method, is inapplicable 

 to one pair of muscles only ; and these only are easily accessible from the 

 surface. These are the crico-thyroid muscles (recte and obliqui, Henle). 

 They extend, in the front of the neck, both vertically and obliquely (from 

 above, downwards, and inwards), on both sides of the conoid ligament, 

 from the thyi'oid to the cricoid cartilage; and they are thrown into strong 

 contraction by two electrodes, placed one on each side of the conoid ligament. 

 Not only can the approximation of the two cartilages be felt by a finger in 

 their interspace ; biit a vocal note sounded diiring the contraction (by which 

 the tension of the vocal cords is increased) will be raised about a semitone. 



" The isolated excitation of the internal laryngeal muscles from the pharynx, 

 is at first attended by gi-eat diflflculties, as well for the operator as for the 

 subject. For the first, rapidity in the introduction of instruments, without 

 unnecessarily touching the root of the tongue or the fauces, complete know- 

 ledge of the anatomy of the parts, with sjiecial reference to the objects of the 

 procedure, steady and certain holding of the electrode in the right place, and, 

 above all, patience, are required. For the patient, the at first constantly- 

 occurring annoyances, such as nausea, or even vomiting, acute hypersemia of 

 the mucous membrane, cough, temporary aphonia, &c. &c., can only be over- 

 come by weeks of steady perseverance. By the necessary perseverance on 

 both sides, we generally at last obtain such a tolerance of these sensitive 

 regions to the contact of the sponge-covered electrode, and to the action of 

 the electric stimulus, that the duration of each single excitation may be 

 extended to half a minute. Many of the persons that I experimented upon, 

 and of my laryngeal patients, became able, while the electrode rested, say in 

 one sinus pyriformis, not only to breathe quietly, but to execute swallowing 

 movements, and to sound notes, during the passage of the ciirrent. It will be 

 evident that movements of the internal soft parts dtiriug the action of the 

 ciirrent cannot wholly be prevented, even after longer practice, since muscular 

 contractions are produced, not only of a reflex character, but also by the 

 direct action of the current itself. The entire disappearance of the laryngeal 

 image from the mirror, at first very perplexing, is soon prevented by 

 practice. 



" The strength of the induced or galvanic current that is applied is best 

 determined by testing it, immediately before, upon the face. An induced 

 current that produces distinct contraction of the frontal muscle, or of the 

 corrugator supercilii, a galvanic current from eight to twelve of Siemens' 

 elements, and producing faint twitching of the facial muscles, will be suflB- 

 cient, on account of the small size of the laryngeal muscles, their superficial 

 situation, and the moisture of the epithelial surface that covers them. 



" As a laryngeal electrode, I use a slender sound, curved like a catheter, 

 screwed into a wooden handle, and insulated up to its point. This point 

 terminates in a Little knob, which is covered by a thin layer of the finest 

 sponge. The double excitor of Duchenne, in a somewhat modified shape, is 

 Tery useful for bilateral internal excitation. To begin with, an excitor may 

 be made from an English gum catheter, by cutting off its extremity down to 

 the eye, and by drilling a hole through the point of the stilet, so as to be able 

 to fasten the sponge securely. Mackenzie's laryngeal galvanizer, and von 



' See " Larvngoscopisches und Laryngotherapeiitischf s,"' Beiifschen Arrhiv fur 

 Klin. Med'icm''B<\. II., H oft 3. 



