5i6 



THE LARYNGOSCOPE. 



lines from the mirror ; they are reflected at the same angle through the mouth into the eye of 

 the observer, who must place himself in the direction of the reflected rays. 



The illumination of the larynx is accomplished either by means of direct sunlight or by light 

 from an artificial source, e.g., an ordinary lamp, an oxyhydrogen lime-light, or the electric light. 

 The beam, of light impinges upon a concave mirror of 15 to 20 centimetres focus, and 10 centi- 

 metres in width, and from its surface the concentrated beam of light is reflected through the 

 mouth of the patient, and directed upon the small mirror held in the back part of the throat. 

 The beam of light is reflected at the same angle towards the larynx by the small throat mirror, 

 so that the larynx is brightly illuminated. The observer has now to direct his eye in the same 



JO*$ %*!? 



Fig. 360. 

 Method of examining the larynx. 



direction as the illuminating rays, which can be accomplished by having a hole in the centre of 

 the concave mirror, through which the observer looks. Practically, however, this is unnecessary ; 

 all that is necessary is to fix the concave mirror to the forehead by means of a broad elastic 

 band, so that the observer, by looking just under the margin of the concave mirror, can see the 



picture of the larynx in the small throat mirror (fig. 360). 

 In order to examine the larynx, place the patient 

 immediately in front of you, and cause him to open his 

 mouth and protrude his tongue. A lamp is placed at 

 the side of the head of the patient, and light from this 

 source is reflected from the concave mirror on the ob- 

 server's forehead, and concentrated upon the laryngo- 

 scopy mirror introduced into the back part of the 

 throat of the patient (fig. 360). 



Oertel was able by means of a rapid intermittent 

 illumination of the larynx through a stroboscopic disc, 

 to study the movements of the vocal cords directly 

 with the eye. Simanowsky put a photographic camera 

 in the position of the eye, and photographed the move- 

 ments of the vocal cords of an artificial larynx. [Brown 

 and Behnke have photographed the human vocal cords.] 

 Laryngeal Electrodes. V. Ziemssen introduces long 

 narrow electrodes into the larynx, to stimulate the 

 muscles and study their actions. Rossbach finds that 

 the muscles and nerves of the interior of the larynx 



Fig. 361. 

 The larynx, as seen with the laryngo 

 scope. L., tongue ; E., epiglottis 



,t ii T) i . t i c in italics iiim uuivcs ui tuo mtciiui ui liiu i 



vallecula; R, glottis \ L.v. t true i vocal may be stimulated by stimulating the skin, m 

 cords; S.M., sinus Morgagni; i.r.*., pe rcutaneously. Those methods are used both for 

 talse vocal cords ; P., position of physiological and therapeutical purposes, 

 pharynx; S., cartilage of San torim ; "L. , ... T r ,-f oz? , , .. 



W., of Wrisberg ; s.p., sinus piriform*! Picture of the Larynx. 1 lg. 361 shows the 



following structures : L., the root of the 

 tongue, with the ligamentum glosso-epiglotticum continued from its middle ; on 

 each side of the latter are V.V., the so-called valleculm. The epiglottis (E.) appears 



