﻿290 Dr. W. Marcet on the Falsetto or 



by the removal of the mucus which constantly moistens the rim 

 of the cords ; their edges thus become sharper and their weight 

 less, while, their elasticity remaining the same, they are shaken 

 into more rapid tremors* The observations I have had the op- 

 portunity of making appear to show that the head- or falsetto 

 sounds are really caused by the vibrations being confined to the 

 rim of the cords ; and I have been able to determine with the 

 laryngoscope the conditions of the larynx which give rise to 

 these sounds. 



When the larynx is examined with the laryngoscope during 

 the act of phonation, the vocal cords are seen to approach each 

 other throughout their whole length and parallel with each other, 

 till they appear in contact, or very nearly so. Any circumstance 

 which interferes with this mutual approximation of the cords, such 

 as weakness of certain of their muscles, as shown by Dr. Morell 

 Mackenzie, or swelling of some parts of the larynx, causes the 

 voice to become very weak or entirely suppressed ; and this is a 

 frequent source of aphonia. When the cords do not meet in 

 their entire length, either an anterior or posterior portion of one 

 of them remaining apart, a sound is produced, but instead of a 

 fair chest-note we have a falsetto or head-sound. 



If a finger be applied to the throat, a depression will be felt 

 between the thyroid and cricoid cartilages ; now on singing the 

 notes of the scale, beginning with the lowest, this depression will 

 be felt to contract, on account of one of the cartilages ap- 

 proaching the other, until with the highest notes it has entirely 

 disappeared — this being due to the action of two of the laryngeal 

 muscles (the crico-thyroid), which tightens the cords, thereby 

 raising the sound of the notes. If, however, in imitation of 

 the Swiss and Tyrolese singers, a chest-note should be followed 

 by the same note sung in a falsetto tone, the space on which the 

 finger rests will be found to have undergone little or no con- 

 traction, notwithstanding the pitch of the head-sound being no 

 less than one octave higher. 



My attention was drawn to the present subject by the remark- 

 able condition of the voice of one of my patients at the Con- 

 sumption-Hospital. He spoke in a sharp clear head- voice, which 

 consisted entirely of " harmonic * 9 sounds. His larynx, of which 

 I obtained a good view with the laryngoscope, exhibited this very 

 peculiar appearance — that the left cord was bent at about the 

 middle, its anterior half coming in contact with the correspond- 

 ing half of the other, while the posterior half remained aside, so 

 that the vibrating- power of the blast from the chest was exclu- 

 sively exerted on the anterior halves of the cords. On applying 

 certain solutions to the cords with a camel-hair brush, I succeeded 

 * Tyndall, ' Lectures on Sound/ 



