temperament, so modulate his voice as to convey to his audience the passions and emotions while feeling none of them himself; so many great singers who are possessed of a good musical ear, a good memory, and natural intelligence, although lacking in supreme artistic temperament and conspicuous musical ability, are nevertheless able to interpret by intonation and articulation the passions and emotions which the composer has expressed in his music and the poet or dramatist in his words.  The intelligent artist possessed of the musical ear, the sense of rhythm, and a well-formed vocal organ accomplishes this by the conscious control and management of his breathing muscles and the muscles of articulation, which by education and imitation he has brought under complete control of the will.  With him visual symbols of musical notes are associated with the visual symbols of words in the mind, and the visual symbols whether of the words or of the musical notes will serve to revive in memory the sound of the one or the other, or of both.  But he produces that sound by alteration of tension in co-ordinated groups of muscles necessary for vocalisation, viz. the muscles of phonation in the larynx, the muscles of articulation in the tongue, lips, jaw, and palate, and the muscles of costal respiration. The mind of the orator, actor, and dramatic singer exercises a profound influence upon the respiratory system of nerves, and thereby produces the necessary variations in the force, continuance, and volume of air required for vocal expression.

Sir Charles Bell, who discovered the respiratory system of nerves, pointed out how the lungs, from being in the lower animals merely the means of oxygenating the blood, become utilised in the act of expelling air from the body for the production of audible sounds—­the elements of human voice and speech.  Likewise he drew attention to the influence which powerful emotions exercise upon the organ of respiration, including the countenance, e.g. the dilated nostrils in anger.  Again, “when the voice suffers interruption and falters, and the face, neck, and chest are animated by strong passion working from within the breast, language exerts its most commanding influence.”

In hemiplegia or paralysis of one half of the body, there is a difference between the two sides for ordinary automatic unconscious diaphragmatic breathing and voluntary or costal breathing.  Thus in ordinary breathing the movements are increased on the paralysed side, especially in the upper part of the chest, while in voluntary breathing they are increased on the sound side.  Hughlings Jackson suggested the following theory to explain these facts:  “Ordinary breathing is an automatic act governed by the respiratory centre in the medulla.  The respiratory centre is double, each side being controlled or inhibited by higher centres on the opposite side of the brain.  Voluntary costal breathing, such as is employed in