Reading Aloud. This is no doubt an excellent exercise, and it has been much recommended by the ancient physicians. To this also may be joined that of speaking. They are both of great advantage to those who have not sufficient leisure or opportunities for other kinds of exercise. To speak very loud, however, or exercise the voice immediately after a meal, is hurtful to the lungs, as well as to the organs of digestion. Singing, as by the vibratory motion of the air it shakes the lungs, promotes in a remarkable degree the circulation of the blood. Hence those sedentary mechanics who, from habit, almost constantly sing at their work, unintentionally contribute much to the preservation of their health.