THE HUMAN VOICE.

CHAPTER I.

ANATOMY OF THE VOICE.

THE special apparatus of the voice is the larynx, an arrangement of ligaments and muscles at the upper part of the windpipe (trachea). The quality of voice depends on the tension and approximation of the vocal cords; its depth or fullness depends on the capacity of the chest, and its power on the associated action of all the respiratory muscles. A brief exposition, therefore, of the structure of the vocal and respiratory apparatus seems to be necessary as a basis for the intelligent training and proper exercise of the organs of music and speech.

The foundation for a normal voice as well as for bodily and mental vigor, and, indeed, for good health, is a welldeveloped thorax, or framework of the chest.

This is constituted of the sternum, or breast-bone, in front, and the twelve pairs of ribs on the sides. The ribs are articulated behind with the twelve dorsal vertebræ of the spinal column. The trachea commences opposite the fifth cerrical vertebræ, and extends to the third dorsal, where it divides into the right and left bronchi, which pass to the right and left lung, and are subdivided and ramified throughout the substance of the lungs. The trachea and bronchial tubes are every

where lined with a mucous membrane, as is the mouth and larynx. Two-thirds of the anterior cylinder of the

An anterior view of the thorax is represented in Fig. 1. 1. The manubrium. 2. Body. 3. Ensiform cartilage. 4. First dorsal vertebra. 5. Last dorsal vertebra. 6. First rib. 7. Head of first rib. 8. Its neck. 9. Its tubercle. 10. Seventh rib. 11. Costal cartilages of the ribs. 12. Last two false ribs. 13. The groove along the lower border of each rib.

trachea are composed of fifteen to twenty cartilaginous rings, which are conducive to the vibrations of air in making trilling sounds.

The thyroid gland (sometimes the seat of goitre, or bronchocele,) is situated upon the trachea above the sternum; it is divided into two lobes, one of which is placed on each side of the trachea.

The lungs occupy the cavity of the chest on each side of the heart. They are conical in shape, tapering above, where they extend beyond the level of the first rib, and

broad and concave below, where they rest on the convex. surface of the diaphragm. The root or upper portion of

Fig. 2 represents the anterior aspect of the anatomy of the heart and lungs. 1. Right ventricle; the vessels to the left of the number are the middle coronary artery and veins. 2. Left ventricle. 3. Right auricle. 4. Left auricle. 5. Pulmonary artery. 6. Right pulmonary artery. 7. Left pulmonary artery. 8. Remains of the ductus arteriosus. 9. Aortic arch. 10. Superior cava. 11. Arteria innominata; in front of it is the right vena innominata. 12, Right subclavian vein; behind it is its corresponding artery. 13. Right common carotid artery and vein. 14. Left vena innominata. 15, Left carotid artery and vein. 16. Left subclavian artery and vein 17. Trachea. 18. Right bronchus. 19. Left bronchus. 20, 20. Pulmonary veins; 18, 20, from the root of the right lung; and 7, 19, 20, the root of the left. 21. Upper lobe of the right lung. 22. Its middle lobe. 23. Its inferior lobe. 24 Superior lobe of left lung. 25. Its lower lobe.

each lung, which retains the organ in position, comprises the pulmonary artery and veins, the bronchial tubes, the bronchial vessels, and the pulmonary plexuses of

nerves.

The minute anatomy of the larynx is shown in figs. 3 and 4.

Fig. 3 is a vertical section of the larynx, showing its ligaments. 1. Body of the os hyoides. 2. Its great cornu. 8. Its lesser cornu. 4. The ala of the thyroid. 5. The superior cornu. 6. Its inferior cornu. 7. Promum Adami. 8, 8. Thyro-hyoidean membrane; the opening near the posterior numeral transmits the superior laryngeal nerve and artery. 9. Thyro-hyoidean ligament. a. Epiglottis. b. Hypo-epiglottic ligament. c. Thyro-epiglottic. d. Arytenoid cartilage. e. Outer angle of its base. f. Corniculum laryngis. g. Cuneiform cartilage. h. Superior thyro-arytenoid ligament. i. Chorda vocalis, or inferior thyro-arytenoid; the elliptical space between the two thyro-arytenoid; is the laryngeal ventricle. k. Cricoid cartilage. 7. Lateral portion of the crico-thyroidean membrane. m. Its central portion. n. Upper ring of the trachea, which is received within the ring of the cricoid cartilage. o. Section of the isthmus of the thyroid gland. p, p. The levator of the glandulæ thyroides.

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Fig. 4 is a side view of the larynx, one ala of the thyroid cartilage being removed. 1. Remaining ala. 2. One of the arytenoid cartilages. 3. One of the cornicula laryngis. 4. Cricoid cartilage. 5. Posterior crico-arytenoid muscle. 6. Crico-arytenoideus lateralis. 7. Thyro-arytenoideus. 8. Crico-thyroidean membrane. 9. One half of the epiglottis. 10. Upper part of the trachea.

The following description of the laryngeal structures is copied from the "Hydropathic Encylopædia :

"The cartilages are: 1. Thyroid (shield-like), which consists of two lateral portions (ala) meeting at an angle in front, and forming the projecting part of the throat, called pomum Adami (Adam's apple). Each ala forms a rounded border posteriorly, which ter

minates above in a superior cornu, and below in an inferior cornu. 2. Cricoid (like a ring), a circular ring, narrow in front and broad behind, where it has two rounded surfaces, which articulate with the arytenoid cartilages. The oesophagus is attached to a vertical ridge on its posterior surface. 3. Two arytenoid (pitcher-like); triangular in form, and broad and thick below, where they articulate with the upper border of the cricoid; above they are pointed and prolonged by two small pyriform cartilages, called cornicula laryngis, which form part of the lateral wall of the larynx, and afford attachment to the chorda vocalis and several of the articulatiug muscles. 4. Two cuneiform; small cylinders, about seven lines in length, and enlarged at each extremity; they are attached by the lower end to the arytenoid, and their upper extremity forms a prominence on the border of the arytenoepiglottidean fold of membrane; they are occasionally wanting. 5. Epiglottis; shaped like a cordate leaf, and situated immediately in front of the opening of the larynx, which it closes when the larynx is drawn up beneath the base of the tongue, as in the act of swallowing. The laryngeal cartilages ossify more or less in old age, particularly in the male.

"The ligaments are: 1. Three thyro-hyoidean, which connect the thyroid cartilage with the os hyoides. 2. Two capsular crico-thyroid, which articulate the thyroid with the cricoid, and with their synovial membranes from the articulation between the inferior cornu and sides of the cricoid. 3. The crico-thyroidean membrane, a fan-shaped layer of elastic tissue, attached by its apex to the lower border of the thyroid, and by its expanded margin to the upper border of the cricoid and base of the arytenoid; above it is continuous with the lower margin of the