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POPULAR SCIENCE MONTHLY. 



occasionally omitted as in the words 'heir/ 'humor,' etc., and infre- 

 quent in the French and quite softly when pronounced. 



The aspirate, which is sounded without approximating the vocal 

 cords, brings us to the whisper in which we have all the elements of 

 speech without the initial vibrations of the vocal cords. That these 

 are not concerned in the whisper is demonstrated by the fact that per- 

 sons, suffering from such forms of paralysis that the cords can not be 

 brought together, can whisper, and that even where the vocal cords 

 have been entirely destroyed by tuberculous or other disease, the patient 

 can still whisper without difficulty. 



As already stated, the modifications of the vowel sounds for articu- 

 late speech are made in the cavities of the mouth, the upper part of 

 the throat and by the nostrils, and are further modified by the posi- 

 tion of the teeth, lips and palate. In perfect singing or speaking, we 

 must have all these parts in a normal condition, and where there is no 

 obstruction, defect, congestion or inflammation, there is no interfer- 

 ence with the free motion or vibration of the parts concerned in voice 

 production. 



The question may be asked how this information about the action 



of the vocal cords has been learned, 

 since, during life, they are out of 

 sight. The use of a mirror by the 

 throat specialist is now so common 

 that it no longer attracts any com- 

 ment, although this method of ex- 

 amining the larynx of a living sub- 

 ject is yet comparatively recent. 

 The method, however, by means of 

 which these parts are inspected is 

 not so well understood, and it 

 would, therefore, be not without 

 interest to explain it. 



The interior of the larynx, be- 

 ing separated from without by its 

 skin and cartilages, is, of course, dark, and must therefore first be 

 illuminated in order to be seen. A small mirror is therefore placed 

 in the back part of the throat, which projects the rays of light down- 

 wards into the parts to be inspected. In order to enable the operator 

 to use the same mirror for inspecting as for illuminating the larynx, 

 he fastens to his forehead a concave mirror which reflects the con- 

 densed light to the throat mirror, and by means of an opening in the 

 center of the head mirror, he is enabled to see the parts of the throat 

 that are illuminated by the throat mirror. This arrangement, which 

 is comparatively simple, has been the foundation of the science of 



Fig. 8. Method of Examining Larynx, 

 THE View of which is shown in the Small 

 Cut at the Left (Ingals). 



