LECTURE IV. General Description of all the Vocal Organs and their Respective Functions, with Illustrative Drawings-The Discoveries made by means of the Laryngoscope and its History -Formation of Voice by the Vocal Cords-Results of the Experiments of Garcia, Türck, Czermak, Sir G. D. Gibb, and others-Drawings of the Vocal Cords when at rest in silent Respiration and when producing Voice-Change of Voice at Puberty— Retention of the Effeminate Voice in Manhood, and proper Mode of Cure-Auxiliary Organs of Voice-Voices of Animals-Quotation from Dr. Carpenter-Brief Summary of the Articulating Organs. my last Lecture I described to you fully the chest and those respiratory organs which are subservient to the phenomena of the voice. This evening I propose occupying your attention with an examination of the structure and functions of those organs which are more immediately concerned in the production of voice. Let me, as I did on the former occasion, endeavour to render my remarks the clearer by a reference to the drawings and diagrams before you, and the first to which I call your attention is this, which is the external appearance presented by the larynx. (See Fig. 3.) And next I have to bring before your notice this, which represents a section and exhibits the interior of the larynx. (See Fig. 4.) And then this, which exhibits the interior of the air-passage in a larynx and trachea slit down behind. The letters in the preceding drawing refer also to this. (See Fig. 5.) It is a most delicate, complicated, and important organ, for it is the instrument that produces all vocal sound. You see it is situated in the anterior portion of the neck, and rises out of the windpipe, and it consists of five principal elastic cartilages, of which one is always very perceptible to the eye, and two of them still more discernible through the integuments that cover them by the sense of touch. Let us then examine them in detail. The tube thus composed is itself called the larynx. This cartilage, G, which you see here connected by ligaments and membranes to the first ring of the windpipe, is called the cricoid, or ring-shaped cartilage. It is, as you can feel by placing the finger on your own necks just at that spot, very firm and solid in structure, serving, in fact, as a substantial foundation for the parts above it. Above this you notice a very marked cartilage. This is termed the thyroid, or shield shaped, cartilage. It is composed of two portions, which unite in front, forming a decided protuberance in the throat of the full-grown man. It has received the fanciful appellation of the pomum Adami, or Adam's apple, from the strange idea, or legend, that a portion of the forbidden fruit stuck in his throat, and has in appearance been perpetuated in all his descendants. The thyroid differs from the cricoid cartilage in this, that it does not surround the larynx, but at the back presents at its 3. Pectoral Fig. 3. External aspect of the larynx, trachea, and thyroid gland. 1. Thyroid cartilage. 2. Cricoid cartilage. 3 3. The superior horns of the thyroid cartilage. 4 4. The thyroid gland. 5. The trachea. 6. Bifurcation of the trachea. 7. Subdivision of the bronchi. extremities prolongations upwards and downwards, E and F. The former are called its great horns, and are connected by ligaments to the tongue-bone, while the latter are much shorter, and are connected by muscles and ligaments to the cricoid cartilage. Now, then, I come to two cartilages much smaller than the others, H. They are named the arytenoid or ewer-shaped cartilages, and are placed in the highest part of the cricoid cartilage. In shape they are pyramidal, and are so connected to each other and the other cartilages by muscles and membranes, as to be capable of motion in several directions. These two cartilages are most important in regard to the production of voice, for it is to them that the vocal cords, O, are attached. And now, before I speak of these wonderful vocal cords and the way in which voice is produced by them, I hope it will not be uninteresting if I give you some account of the invention and means by which our present knowledge of human vocal phenomena has been attained. The subject has always been one of the greatest interest, especially to physi ologists; and as early as the seventeenth century attempts had been made, by means of artificial contrivances, to obtain a view of the more deeply situated portions of the interior of the throat in the living human subject. But no name, I think, calls for any special mention until we come to that of Dr. Babington, who, at a meeting of the Hunterian Society in March 1829, showed an instrument he had constructed for rendering visible the interior of the larynx. It was, really, almost essentially the same as the instrument that is now in use for that purpose, and is thus described in the third volume of the "Medical Gazette," at page 585 "It consisted of an oblong piece of looking-glass, set in silver wire, a long shank. The reflecting portion is placed against the palate, while the tongue is held down by a spatula, when the epiglottis and the upper part of the larynx became visible in the glass." The impetus now seems to have been given to further improvements and discoveries. In France, MM. Traupeau and Belloc published in A. Great cornu of the hyoid bone. B. Body of the os hyoides. C. Small cornu of the hyoid. D. Thyroid cartilage. E. Upper cornu of the thyroid. F. Lower cornu of the thyroid. G. Cricoid cartilage. H. Arytænoid cartilage. I. Cartilage of Santorini. J. Crico-arytenoideus posticus muscle. K. Cuneiform cartilage. L. Epiglottis. M. Thyro-hyoid ligament. N. Crico-thyroid ligament. O. True chorda vocalis. P. False chorda vocalis. Q. Ventricle of the larynx. R. Rima glottidis. S. Sacculus laryngis. U. Arytæno-epiglottid fold. V. Arytænoideus posticus muscle. W. Interior of the trachea. X. Muscular part of the trachea. Y. Rings of the trachea. Fig. 5. 1837 the result of the investigation they had made by means of an instrument made by an ingenious mechanic of the name of Selligue, and which they call a speculum laryngis; and in 1838 M. Beaumes, of Lyons, exhibited a mirror he had constructed for examining the throat, larynx, and back of the nostrils; while in England the names of the late Mr. Avery and Dr. Warden should also receive honourable mention for their efforts in the same direction. But I must pass on now to a name that must ever occupy a very high place in the list of those distinguished men who have, within the last twenty years, not merely metaphorically, but literally, thrown so much light upon the larynx. I mean M. Garcia, the celebrated teacher of singing, and brother of the great prima donna of thirty years ago, Madame Malibran. M. Garcia had for many years made the anatomy and physiology of the larynx, as the organ of voice, a subject of constant study, and had long felt a great desire to witness the mechanism and movements of the organ of the human voice in the act of singing. This he carried out successfully by a very simple plan, making his own throat the subject of his experiment, when he was at Paris in September 1854. Standing with his back to the sun, he held a looking-glass in his left hand before his face; the sun's rays were thus reflected by the glass into his open mouth. Then, having previously warmed a small mirror, similar to that used by dentists, he placed it at the back of his mouth, and then he saw reflected in the mirror his own larynx, with the vocal cords in action as he sung an air. He next performed a series of experiments in relation to the movements of the vocal cords and the general action of the larynx in various persons in the act of singing, with a view to determine the chest registers of the voice, and the means by which the falsetto is produced. The result of M. Garcia's observations were given by him in a very interesting paper entitled "Physiological Observations on the Human Voice," which were read before the Royal Society on May 24th, 1855, and which, if you desire to read (and well will it repay perusal), you will find in the Proceedings of that Society for the year 1855. Many important observations and discussions resulted from the publication of this paper. The eminent physiologist, Dr. Türck, of Vienna, became acquainted with this paper, and was induced by it to use the laryngeal mirror in the wards of the general hospital of that city during the year 1857, for the purpose of making a diagnosis in cases of diseases of the larynx. In the autumn of that year he lent his mirrors to Dr. Czermak, who very soon made a great improvement in the invention. Hitherto sunlight had been the means employed for illuminating the interior of the throat, which, of course, was not always to be attained. He conceived the idea of adapting the ophthalmoscopic mirror, designed by Ruete, for the purpose of concentrating and reflecting artificial light, thus making the laryngoscope, as he now termed his instrument, available at all times as a means of inspecting the larynx and of guiding the hand in the application of local remedies. He also employed mirrors of various sizes and perfected them in every way. The name of Czermak has ever since been prominently associated with what is termed the art of laryngoscopy, though we ought not to omit mentioning, with high honour, the names of Sir G. D. Gibb, Dr. George Johnson, and Dr. Mackenzie in our own country, and those of Battaille and Merkel on the Continent. Czermak travelled over the best part of Europe in order to make known his researches, and the views he held in consequence. But with a most praiseworthy modesty he never failed to give Garcia all the merit his originality deserved; and the very first essay Czermak published, which was in 1858, bore as its title "Physiological Researches with the Laryngeal Mirror of Garcia," showing the importance and value he attached to the experiments and researches of |