The absolute truth of the foregoing remarks may easily be proved by singing the vowels at either extreme of the "vowel scale of nature," viz., "oo and ee," over the whole compass of the voice, having regard to the beauty of tone. Although the singer may be quite unaware of the science underlying the fact, it will be found that the quality of the voice at the bottom of its range as these vowels are sung is very different from that at the top of the range, the alterations taking place in almost imperceptible gradations. By reference to the foregoing pages of this book it will be seen that the late Emil Behnke attached great importance to vowel training, and exemplifications of his methods are to be found in "Voice Training Exercises" and "Voice Training Studies" written in conjunction with C. W. Pearce, Mus.Doc. The subject is also fully explained in "Voice, Song, and Speech," by Lennox Browne, F.R.C.S., and Emil Behnke; and the whole matter is most ably discussed in "Pronunciation for Singers," by the late Dr. A. J. Ellis, F.R.S., published by Messrs Curwen & Sons. In thus strongly advocating education of the resonator in the production of vowel sounds in singing, let me not be supposed to ignore the necessity for also cultivating pronunciation of consonants, which have been termed the checks and stops of sound. Clearness of enunciation and purity of pronunciation, which are great aids to the voice, and possess a charm all their own, depend upon both vowels and consonants being accurately rendered. The English are the worst enunciators of all European peoples, and their custom is to lay the blame on the language, than which none other is deemed by them so unvocal. There is, however, a vast amount of sonority and musical charm in our grand and noble language, second only to the Italian, when properly spoken. The cultivation of pure, accurate, and refined pronunciation in speech will greatly facilitate good enunciation in singing, and should he sedulously acquired; for there are numbers of vocalists who leave us in doubt as to whether the words they sing are English, French, Italian, or German; while the number of those who mispronounce words in a deplorable manner is legion. FORCING THE REGISTERS. The next factor which has much to do with voice failure is forcing the registers beyond their proper point of change. The erroneous belief appears to exist that, by carrying up the registers a few notes beyond their natural limits, the tones thus produced are fuller and richer. But if in training a voice this practice be followed the result will be serious injury to the vocal organ.