Physics is not a series of disconnected subjects, including Mechanics, Sound, Light, Heat, and Electricity. It is, on the contrary, a body of well-organized truth, forming one great whole; illustrating, as do few other subjects, what Dickens called "the universal dove-tailedness of things."

Elements of Physics: For Use in High Schools, From the Preface to the First Edition (p. v), The Macmillan Co. 1909