This subject has also most important bearings on the learning of languages. One is born with tendencies toward certain mouth positions, etc., and from infancy he is constantly using the resonance-chambers in certain characteristic ways. In the course of years these positions, etc., become such fixed habits that it is difficult to change them, so that for this as well as many other reasons the learning of languages by persons beyond a certain age is a difficult matter. But to all students of a foreign tongue it is really essential to explain the physical mechanism by which the various sounds are made. The author has known an adult to struggle for months with French and German pronunciation, and get into a state of discouragement, fearing that he never would be able to learn the languages in which he wished to speak and sing, when a few moments spent in explaining just what we have written above for vowels, and what we have earlier and shall now more fully set forth in this chapter as regards consonants, have been followed by the lifting of the cloud from the mind and of a load of heaviness from the heart. The learner should (1) hear the sound (elemental--a vowel, say) from the lips of the teacher, and actually perceive just what that sound is--_i.e._, he must really hear it; (2) observe the shape of the resonance-chambers; (3) try to produce the same shape of his own, and under the guidance of his ear and his eye (watching the mouth of the teacher) so utter the sound correctly. This sound should be fixed in the mind, and the ear trained by comparing it with other sounds, as the wise teacher will do, and require imitations. Any language can be pronounced correctly in a short time, if this method be followed. It is, indeed, the only one that rests on science and common sense. The student when away from the teacher, after he has once learned to form the vowels correctly, should practise with a hand-glass before him for some time, at least. The learning of a new language is the acquiring of a new mouth, or, at all events, entirely new methods of using the old one. In reality, however, this is not so fully the case as it at first seems. In all the languages one wishes to acquire, the same vowels occur, and for the learner it is often a question of lower or higher pitch, or greater or less breadth, though all this involves the formation of new habits and the fighting of old ones, and often in the case of the adult the struggle is a long-continued and severe one. Some nations speak at a lower pitch than others, and if a foreigner enunciate ever so well, yet at the pitch of his own and not that of the new language, his utterance may seem foreign. The Germans speak at a much lower pitch than Americans, and their tongue, even when grammatically spoken by the latter, is apt to have a sort of foreign flavor. It slightly disturbs the listener, who is not accustomed to hear his mother-tongue transposed into another key, so to speak.