252 EXPERIMENTAL PHYSIOLOGY. 



form. The observer seats himself opposite and close to the 

 patient ; places the large mirror on his forehead, and either 

 looks through the central hole in it with one eye, or raises 

 it so that he can just see under its lower edge. 



(b.) Seated in front of the patient, he directs a beam of 

 light until the lips of the patient are brightly illuminated. 

 The patient is then directed to incline his head slightly 

 backwards, to open his mouth wide, and protrude his tongue. 

 Place a clean handkerchief over the tongue, and give the 

 patient the handkerchief to hold, which secures that the 

 tongue is kept protruded and well forward. Move the large 

 mirror until the uvula and back of the throat are brightly 

 illuminated, the operator moving his head slightly to and 

 from the patient until the greatest brightness is obtained. 



(c.) Take the small laryngeal mirror in the right hand, 

 and warm it gently over the lamp to prevent the condensa- 

 tion of moisture on its surface. Test its temperature on the 

 skin of the cheek or the back of the hand. Holding the 

 handle of the mirror as one does a pen, rapidly carry it 

 horizontally backwards, avoiding contact with any structures 

 in the mouth, until its back rests against the base of the 

 uvula. At the same time, direct the beam of light upon 

 the laryngeal mirror, when an inverted image of the larynx 

 will be seen more or less perfectly. 



(d.} By moving the laryngeal mirror, not, however, 

 pressing too much on the uvula, or continuing the obser- 

 vation for too long a time, one may explore the whole of the 

 larynx. Perhaps only the posterior part of the dorsum of 

 the tongue is seen at first ; if so, slightly depress the handle 

 of the mirror, when the "curved fold of the slightly yellowish 

 epiglottis and its cushion, with the glosso-epiglottidean folds, 

 come into view. In the middle line are the true vocal cords, 

 which are pearly white and shining, and best seen when a 

 high note is uttered, and between them the chink of the 

 glottis. Above these are the false vocal cords, which are red or 

 pink, the ary-epiglottidean folds, with on each side the carti- 

 lages of Wrisberg furthest out, the cartilages of Santorini 

 internal to this, and the arytenoid cartilages near the middle 

 line. 



