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 is conditioned by the forces acting upon him from without. In Part II. we have chapters on the "Origin of the Human Race"; "Prehistoric Relics"; "Centers of Creation"; and "Dispersion of the Human Race." Finally, in Part III., the author treats of "The Development of the Psychic Faculties"; "The Development of Language"; and "The Development of Civilization." Under the last-named head are chapters on the development of religious and moral ideas, of social relations, and of scientific and industrial activities.

is doubtful whether the musical public is in any degree aware of the revolutionizing contribution which contemporary scientific investigation is making to the theory of music, building a solid structure where before lay an interminable swamp of bad logic, fanciful speculation, and impossible metaphysics. Yet it was as long ago as 1863 that Helmholtz published his large epoch-making work ("The Sensations of Tone as a Physiological Basis for the Theory of Music"). Mr. Ellis in 1875 furnished an excellent English translation, adding several learned appendices of his own; and James Sully, Grant Allen, and others have written brief expository chapters and essays on Helmholtz's theory. A few years ago a society was organized in London for the study and propagation of the new order that had come into the complexities of musical theory. Mr. William Spottiswoode was president. It was at the invitation of Mr. Spottiswoode, as secretary of the Royal Society, that Mr. William Pole delivered at the Royal Institution of Great Britain the lectures on "The Philosophy of Music," which now appear in the book of that title.

This work for the first time places before the non-scientific reader a full, well proportioned, and easily followed exposition of the new illumination which has fallen upon speculative music. This is a most important task, and to have performed it so well as Mr. Pole has done is a merit almost equal to that of original investigation. For the subject is burdened with a mass of historical and technical minutiae that required the most careful sifting out of the non-essential; then came the task of leading the uninitiated reader to entirely new conceptions, and of eradicating or directly inverting many old and long-established ones. Altogether a more trying subject for the expository art could not have been found, and it is not too much to say that the musical reader may find in these twenty-one orderly chapters something beyond their subject matter, viz., an excellent illustration of the systematizing and clarifying influence that scientific methods may have upon mental activity.

The author, preparing the way with a chapter on elementary acoustics, states the phenomena of overtones, and then shows their action in determining the tone-character or timbre of the various musical instruments. These overtones also constitute the natural basis for the scales, for melody, tonality, and harmony—in so far as these have a natural basis. For æsthetical influences, local, individual, and transitory, have played the largest part in giving to music its present form. The problem is to determine the parts played, on the one hand, by physical or physiological principles, on the other by æsthetical requirements, in that artistic growth which has from the simple Greek tetrachord developed modern music in all its complexity.

As to the origin of the diatonic scale, following Helmholtz always, the author believes the octave and its primary division into fifth and fourth to have arisen from the natural structure of a musical sound, which by its overtones embraces these three intervals. The octave, with its fifth and fourth, admitted of seven different divisions, the seven Greek modes. From these the requirements of early ecclesiastical music eliminated two modes, leaving five. The coming of harmony, under Palestrina, removed three more modes, unsuitable because of their paucity in concords; and the remaining two survive as our modern major and minor. This gradual change, a genuine