PHOTOGRAPHY OF THE LARYNX. 



395 



In photographing the larynx, Prof. French uses the electric arc 

 light. The apparatus is shown in Fig. 217. It consists of an 

 automatic 2000-candle-power lamp partly inclosed in a metal box. 

 The front face of the box carries a condensing lens which, when 

 placed 9 inches from the arc, gives a focal distance of 20 inches. 

 This relation of light and lens is found to give the most satisfac- 

 tory illumination. The lamp and accessories are fitted to a narrow 

 board which is placed upon a table of sufficient height. The light 

 can be raised or lowered by means of a device designed for that 

 purpose.* The rheostat is placed upon a shelf beneath the table 

 top. The whole light outfit is but a modification of the electric 

 stereopticon. This one is so arranged that by adding a second 



FIG. 217. Showing the manner in which photographs of the larynx and posterior 

 nares are secured with the aid of the arc light. 



condensing lens and an objective lens to the end of the cone- 

 shaped tube in front it can be used as a projecting lantern. 



In speaking of the action of the glottis, Prof. French says that 

 with all his experience he has not yet permitted himself to formu- 

 late a theory of the action of the glottis in singing, for even now, 

 after a large number of studies have been made, the camera is con- 

 stantly revealing new surprises in the action of the vocal bands 

 in every part of the scale. The movements of the larynx in a 

 much larger number of subjects must be revealed, grouped, and 

 recorded before definite conclusions can be drawn. 



Most of our past knowledge on the subject of the changes in 

 the larynx during singing has been obtained from inspection of 

 this organ through the laryngoscope. As these changes follow 

 each other too rapidly to be appreciated by the eye, much of this 

 knowledge has been found to be erroneous. The photographic 



