254 EXPERIMENTAL PHYSIOLOGY. 



forehead, and the observer places himself in front of a toilet 

 mirror. In a line with and slightly behind the mirror, and 

 on one side of the observer, place a lamp. By means of the 

 reflector, the image of the fauces seen in the mirror is illuminated. 

 Introduce the laryngeal mirror, when the image of the larynx is 

 seen in the toilet mirror. 



Fig. 119. Koenig's Manometric Flame Apparatus. 



6. Analysis of Vowel Sounds. 



k (a.) Use Koenig's apparatus, as shown in Fig. 119. 

 Connect the tube of the capsule with the gas supply, light 

 the gas jet, and sing the vowels A, E, I, O, U in front of 

 the open trumpet-shaped tube shown in the figure. With 

 the other hand rotate the mirror (M), and observe the 

 serrated reflection of the flame in the mirror, noticing how 

 the image in the mirror varies with each vowel sounded. 



