To build a bridge between the art of music and the physical and physiological sciences of sound was the task that Helmholtz set himself when he entered upon the classical work which has served ever since as the basis of all research in this field. How far he succeeded in accomplishing his object we need not discuss here, but he certainly laid the foundation of a very extensive practical science, devoted alone to the investigation of the laws of sound in all the varied forms in which we meet them in music. The phonologist, as he should be called who is occupied with this study, finds himself, however, in a somewhat isolated situation. The schools of experimental physics are generally too busy with electricity and kindred subjects to give much thought to sound, although the telephone and phonograph have to some extent forced their attention in that direction. Among physiologists, very few are occupied with sound, and the peculiar skill required in studying the vocal organs, which has necessitated the formation of a special branch of medicine, diminishes their number still further.