Speech is after all only a system of gestures, having the peculiarity that each gesture produces a characteristic sound, so that it can be perceived through the ear as well as through the eye. Listening to a speaker instead of looking at him tends to make us think of speech as essentially a system of sounds; but it is not; essentially it is a system of gestures made with the lungs and larynx, and the cavities of the mouth and nose. We get still farther away from the fundamental facts about speech when we think of it as something that can be written and read, forgetting that what writing, in our clumsy notations, can represent is only a small part of the spoken sound, where pitch and stress, tempo and rhythm, are almost entirely ignored. But even a writer or reader, unless the words are to fall flat or meaningless, must speak them soundlessly to himself. The written or printed book is only a series of hints, as elliptical as the neumes of Byzantine music, from which the reader thus works out for himself the speech-gestures which alone have the gift of expression.