6/7 THE STIFFENING RODS OF THE BODY-MACHINE 210 XX. OUR TELEPHONE EXCHANGE AND ITS CABLES 216 XXI. THE HYGIENE OF BONES, NERVES, AND MUSCLES 228 How to Get and Keep a Good Figure 228 Our Feet 230 Sleep and Rest 232 Disorders of Muscles and Bones 233 Troubles of the Nervous System 235 XXII. EXERCISE AND GROWTH 241 XXIII. |