48 SYSTEMS OF TREATING STAMMERING inflection-signs, intensity-signs, etc.; and others by interpolated remarks directing the pupil to repeat certain parts of the exercise, and to breathe at partic- ular points in a particular manner. At one point the exercise may require chest breathing, at another costal breathing, and so on. As in the respiratory exercises, the time is measured by a metronome, or is given by an instructor leading the class with a baton. At this point it may be well for us to consider the virtues of these exercises. It may be said of vocal exercises in general that most of them are useful as ordinary elocutionary measures; and that the majority of them would be beneficial to the stammerer in some respects. But the exercises are usually of benefit for their psycho- logical effect rather than for their elocutionary value. The exercises exert a favorable influence through suggestion when the stammerer has confidence in their therapeutic power; and for a time, at least, they may remove such secondary causes as fear, bewilderment, and inhibitive auto-suggestion. It seems probable that the vocal exercises, when practised several hours a day, may intensify the stammerer's auditory ima- gery, and thus exert a beneficial influence on speech. But if an intensification of the imagery occurs, it is temporary; and the improvement in speech is usually lost when the exercises are discontinued. Probably some of the vocal exercises influence the kinaesthetic