In whispering, the voicebox occupies a different position in the throat for each vowel. I invite the reader to try the following curious experiment. Let him take the larynx gently between the thumb and the first finger, and then whisper OO (as in "food,") OH, AH, A (as in "name,") and E (as in "bee"). He will find that the voicebox rises with every succeeding vowel until at last it has completely slipped away from between the finger and thumb. Each one of these whispered vowels has, as first ascertained by Helmholtz, its exact pitch, whether uttered by a little child or by an old man, and the effect of the rising of the voicebox is to shorten the resonator, whereby the raising of the pitch is produced.
I stated on page 41 that the vocal ligaments were capable of being stretched by the ring-shield muscles, and that the pitch of the tones produced by their vibrations depended mainly on their tension. As we are now taking note of such movements of the voicebox as may be either seen or felt in the throat, we will take the opportunity of trying whether my statement can be verified. Let the reader, therefore, do as follows:—(1) Place the finger on the shield cartilage, and press it vigorously backward. (2) Sing loudly any high tone that is well within your compass. Hold this tone steadily, and be quite sure you do not alter its pitch. (3) Now suddenly remove your finger, continuing to sing as before. What is the result? Your tone is raised by a third, or even more, according to the amount of pressure you exercised on the shield. And how did this result come about? In this way: By pressing the shield backwards you elongated the ring-shield muscles, thereby counteracting their stretching influence, and at the same time slackening the vocal ligaments. The tone you sang while doing this was, we will say C'. By releasing the shield you enabled the ring-shield muscles to contract again, thereby putting the vocal ligaments on the stretch as they were at first. That changed your C' to E', or higher still. Have I proved my assertion?
Now one more test, if you please. I pointed out to you on [page 34] an opening between the shield and the ring. You will see it on plate [V], No. 10. Please sing a low tone; place your finger gently on the shield, and move it downwards. You will soon discover a little hollow which corresponds with the opening I just mentioned, and into which you can easily put part of the tip of your finger. Now sing up the scale, and take care to keep the tip of your finger in the hollow. Remember that in singing up the scale your voicebox will rise, which movement you must follow, or you will lose the place. If you do this carefully, you will find that the hollow gets smaller and smaller by degrees until at last it closes entirely, and you can no longer find a trace of it. Now sing down again, keeping your finger on the same spot. You will soon notice the hollow again, and it will continue to get larger and larger until you arrive at the bottom of your scale.
This, of course, is but another way of showing the mechanism by which the pitch of your tones is raised or lowered, and we have proved the same thing by our preceding experiment. But I asked you to try this chiefly because it will enable you to put a check upon my statements with regard to the registers of the voice, a subject which I propose to discuss in another chapter.
THE LARYNGOSCOPE, AND HOW TO USE IT.
The Laryngoscope in its simplest form is a thin circular mirror, about three-quarters of an inch in diameter, set in a metal frame, and fastened at an angle of 120° to a piece of wire from three to four inches long, which is put into a small wooden handle not much thicker than a pencil, and about the same length as the wire. By help of the laryngoscope we can either see our own larynx or that of another person. The easiest experiment is upon the larynx of some one else. In this case, the person to be operated upon sits facing the sun, the head slightly bent backwards, and the mouth wide open. If he has not sufficient control over his tongue to prevent it from arching up, he must gently hold its protruding tip with a pocket handkerchief between his thumb and forefinger. The mirror is now slightly warmed to prevent its becoming dimmed by the moisture of the breath, and then, holding it like a pen, the operator introduces it into the throat so that it touches the uvula. This must be done lightly yet firmly, care being taken not to bring the mirror into contact with the base of the tongue. The rays of the sun falling upon the mirror are reflected downwards into the voicebox, the image of which is clearly visible in the mirror. In making observations upon oneself, a second mirror in the shape of an ordinary hand looking-glass is necessary to reproduce the image in the small mirror. This is the way in which the renowned professor of singing, Senor Manuel Garcia, made those famous "Observations on the Human Voice," communicated to the Royal Society by Dr. Sharpey, on May the 24th, 1855. Similar attempts had been made before; for instance, in 1827 by Babington, in 1838 by Baumès, in 1840 by Liston, and in 1844 by Warden and Avery. But they had all ended in failure, an occasional glimpse of some parts of the voicebox being the only result obtained. Garcia, however, brilliantly succeeded where all his predecessors had failed, and was the first not only to see the vocal ligaments, but to see them in the act of singing, and to see them so clearly as to be able to give an account of their minutest movements. The instrument has since been greatly improved, and the process of investigation has become a science. Medical men all over the world have laid hold of it, and suffering humanity is daily benefited by it. But Garcia is the man who produced the first results, and to him, therefore, is due the credit of being practically the inventor of the laryngoscope.
It is almost incredible, but it is true, that this splendid invention was received coldly and with distrust in this country, and had it not been for Dr. Johann N. Czermak, Professor of Physiology at the University of Pesth, the matter would, in all probability, have been forgotten. But this gentleman recognized the value of Garcia's invention, and he at once went enthusiastically to work, and pushed on vigorously in the way which Garcia had opened for him. He constructed an apparatus which enabled him, by making use of artificial light, to work without interruption and without waiting for the sun to shine. He then made his first attempts on himself in order to become acquainted with the conditions which have to be fulfilled by the observer as well as by the person to be operated upon. In this way he soon became a master of the new process, which he immediately brought under the notice of the profession by giving lectures and demonstrations in the chief towns of Europe.
More than twenty years have passed since then, and the laryngoscope has, during that time, been made excellent use of, not only for the alleviation of suffering, and the cure of disease, but also for its original purpose—i.e., the exploration of the mechanism of the human voice.
My own connection with the matter has arisen through my desire to sift contradictory statements made by various observers. Having read many English, German, and French books on the subject, I was in position to pick up a hint here, and to get some good advice there, and the consequence was that I was able to pursue a course which made me familiar with the use of the laryngoscope in a very short time. As my experience may be useful to others, I will briefly relate how I proceeded.