1862.] 143 



IV. "Observations made on the Movements of the Larynx 

 when viewed by means of the Laryngoscope/' By JOHN 

 BISHOP, Esq., F.R.S. Received June 5, 1862. 



I had not contemplated any further investigation on the physiology 

 of intonation by the human organs of voice, had not my attention 

 been aroused by the facility afforded by the apparatus of Professor 

 Czermak, of seeing what actually takes place in the larynx during the 

 production of vocal sounds. 



The tact of the Professor in applying the instrument in his own 

 case, and the impunity with which he is able to bear its presence in 

 the sensitive parts of the pharynx, are great advantages. 



In many persons the presence of any foreign body so applied, 

 usually produces, by reflex action, a sense of sickness in the stomach. 



In ordinary breathing the glottis is wide open, and the arytenoid 

 cartilages are thrown wide apart ; but on the production of the most 

 simple sound, these cartilages are suddenly and rapidly closed, and 

 the edges of the vocal cords come into juxtaposition with each other 

 so as to leave no interval between them in their entire length. 



In the production of the lower tones of the voice the vocal cords 

 may be seen to vibrate throughout their whole length, and even at 

 their prolongations at the base of the arytenoid cartilages ; they seem 

 to vibrate also throughout their entire breadth. As the pitch of the 

 tones rises in the scale, the length of the cords in a state of vibration 

 diminishes, and they are pressed more closely against each other : as 

 the tones become more acute, the pressure is increased, and the 

 tension of the vocal cords augmented ; the breadth of the cords is 

 also diminished. 



When the chest tones have arrived at the limit of the scale of acute 

 range, and the falsetto tones commence, the glottis is seen to be more 

 closely pressed together, and the edges only of the vocal cords are 

 suffered to vibrate, as Garcia has already observed. On the other 

 hand, while the chest tones are produced, a larger surface of the 

 vocal cords is in a state of vibration. When the falsetto tones are 

 produced, it appears that the very extreme edge only of the cord 

 vibrates, and a much less expenditure of breath is required. While 

 the highest notes of the voice are intoned, the vocal cords are so 

 closely pressed together, that a small portion only of the glottis is 



