learn by early experience that such and such a tone indicates such and such an emotion, and this they make out partly by finding themselves uttering such tones when their feelings have brought their faces to the appropriate attitudes, and partly by observing the expression of voice in others. At three or four years old they are to be seen in the act of acquiring this knowledge, turning round to look at the speaker's face and gesture to make sure of the meaning of the tone. But in later years this knowledge becomes so familiar that it is supposed to have been intuitive. Then, when men talk together, the hearer receives from each emotional tone an indication, a signal, of the speaker's attitude of body, and through this of his state of mind. These he can recognize, and even reproduce in himself, as the operator at one end of a telegraphic wire can follow, by noticing his needles, the action of his colleague at the other. In watching the process which thus enables one man to take a copy of another's emotions through their physical effects on his vocal tone, we may admire the perfection with which a means so simple answers an end so complex, and apparently so remote.
By eliminating from speech all effects of gesture, of expression of face, and of emotional tone, we go far toward reducing it to that system of conventional articulate sounds which the grammarian and the comparative philologist habitually consider as language. These articulate sounds are capable of being roughly set down in signs standing for vowels and consonants, with the aid of accents and other significant marks; and they may then again be read aloud from these written signs, by any one who has learnt to give its proper sound to each letter.
What vowels are, is a matter which has been for some years well understood. They are compound musical tones such as, in the vox humana stop of the organ, are sounded
- See Helmholtz, 'Tonempfindungen,' 2nd ed. p. 163; McKendrick, Text Book of Physiology, p. 681, &c., 720, &c.; Max Müller, 'Lectures,' 2nd series, p. 95, &c.