THE VOICE 313 



mirror attached to a long handle be placed back into the 

 upper part of the throat; the handle near the mirror must 

 be bent at an angle of 45, so that we may look "around 

 the corner/' so to speak, behind the tongue. The position 

 which the mirror must assume will be understood by refer- 

 ence in Fig. 51. A view of what may be seen under favor- 

 able circumstances, during tranquil inspiration, is represented 

 in Fig. 74. The vocal cords are there shown as narrow, 

 white bands, on each side of the central opening, and since 

 the image is inverted, the epiglottis appears uppermost. The 

 rings partly seen through the opening belong to the trachea. 

 This little mirror is the essential part of an instrument, which 

 is called the laryngoscope, and simple as it may seem, it is 

 accounted one of the most valuable of the recently-invented 

 appliances of the medical art. 



10. The Production of the Voice. During ordinary tranquil 

 breathing, no sound is produced in the larynx, true vocal tones 

 being formed only during forcible expiration, when, by an 



FIG. 75. THE DIFFERENT POSITIONS OF THE VOCAL CORDS 



A, The position during inspiration. B, In the formation of low notes. C, In the formation 



of high notes 



effort of the will, the cords are brought close together, and are 

 stretched so as to be very tense. The space between them is 

 then reduced to a narrow slit, at times not more than y^j- of 

 an inch in width ; and the column of expired air being forced 

 through it causes the cords to vibrate rapidly, like the strings 

 of a musical instrument. Thus the voice is produced in its 

 many varieties of tone and pitch; its intensity, or loudness, 

 depending chiefly upon the power exerted in expelling the air 



10. The formation of true vocal tones ? 



