This division includes the use made of the qualities of sound for the purpose of adding to the melodiousness of verse, or of expressing in some measure the ideas to be conveyed by means of the very sounds employed. Sometimes this takes the form of alliteration, differing from that of early English verse only in that it follows no regular structural laws. On the other hand, it may take the form of onomatopœia, the figure of speech in which sound and sense are closely related,—as in descriptive words like buzz, hiss, murmur, splash, and the like. The term Tone-color is formed by analogy with the German Klangfarbe, an expression apparently due to the feeling that the sound-qualities of speech have somewhat the same function as the various colors in a picture. It is unquestionably true that the selection of sounds, whether vowel or consonantal, has much to do with the melodious effect of very much poetry. The poet may choose the different sound-qualities (so far as the sense permits) just as the musician may choose the varying qualities of the different instruments in the orchestra or the different stops in the organ.
Strictly speaking, this matter of Tone-color is not a part of verse-form in the same sense as matters of rhythm, rime, and the like; for it may appear in prose as well as in verse, and is not in any case reducible to formal principles or laws. Yet its use in actual verse is so important, and it is so closely related to the use of sound-quality in the form of rime and alliteration, that it seems well to include it here.[15]
Dr. Guest treats sounds as having in themselves the suggestion of more or less definite ideas, this suggestiveness being explainable by physical causes. Thus the trembling character of l suggests trepidation, as in "Double, double, toil and trouble." R suggests harsh, grating, or rattling noises; the sibilants are appropriate to the expression of shrieks, screams, and the like; b and p, because of the compression of the lips, suggest muscular effort; st, from a sudden stopping of the s, suggests fear or surprise; f and h also fear, because of their whispering quality. Hollow sounds (au, ow, o, and the like) suggest depth and fulness. Guest quotes in this connection an interesting passage from Bacon's Natural History (ii. 200): "There is found a similitude between the sound that is made by inanimate bodies, or by animate bodies that have no voice articulate, and divers letters of articulate voices; and commonly men have given such names to those sounds as do allude unto the articulate letters; as trembling of hot water hath resemblance unto the letter l; quenching of hot metals with the letter z; snarling of dogs with the letter r; the noise of screech-owls with the letter sh; voice of cats with the diphthong eu; voice of cuckoos with the diphthong ou; sounds of strings with the diphthong ng.
A. W. Schlegel went even farther in suggesting a subtle symbolism in sounds apart from descriptive qualities. Thus he regarded a as suggestive of bright red, and as symbolizing youth, joy, or brightness (as in the words Strahl, Klang, Glans); i as suggestive of sky-blue, symbolic of intimacy or love; and so with other vowel sounds. (See Ehrenfeld's monograph, p. 57.) In general it may be said that it is dangerous to attempt to explain the special effects of tone-color in verse, except where it is obviously descriptive, the appreciation of such effects being a subtle and a more or less individual matter. On this subject Mr. Gurney makes some interesting observations, in the essays cited above. He believes that the pleasurable effect of the sound-qualities in verse can never be dissociated from the sense of the words; that the most melodious verse cannot be appreciated if in a foreign language, unless read with particular expressiveness; and that the pleasure derived from what we roughly call melodious or harmonious verses is always due to the mystical combination of the appropriate sound with the poetic content.
Dr. Johnson ridiculed the idea of tone-color, as appearing in Pope's teaching that the sound should be "an echo to the sense." See his Life of Pope, and especially the Idler for June 9, 1759, in which he describes Minim the critic as reading "all our poets with particular attention to this delicacy of versification." Such a critic discovers wonders in these lines from Hudibras:
"Honor is like the glossy bubble,
Which cost philosophers such trouble;
Where, one part crack'd, the whole does fly,
And wits are crack'd to find out why."
"In these verses, says Minim, we have two striking accommodations of the sound to the sense. It is impossible to utter the first two lines emphatically without an act like that which they describe; bubble and trouble causing a momentary inflation of the cheeks by the retention of the breath, which is afterwards forcibly emitted, as in the practice of blowing bubbles. But the greatest excellence is in the third line, which is crack'd in the middle to express a crack, and then shivers into monosyllables."
In an article on "Some Technical Elements of Style in Literature" (originally published in the Contemporary Review, April, 1885; reprinted in the Scribner edition of Stevenson's Works, vol. xxii. p. 243) Robert Louis Stevenson discussed some of the more subtle effects of vowel and consonant color, as appearing in both prose and verse. The combination and repetition of the consonants PVF he found to be particularly frequent. The pervading sound-elements in the two following passages he analyzed by means of the key-letters in the margin:
(KANDL)"In Xanadu did Kubla Khan
(KDLSR)A stately pleasure-dome decree,
(KANDLSR)Where Alph the sacred river ran
(KANLSR)Through caverns measureless to man,
(NDLS)Down to a sunless sea."
(Coleridge.)