The time spent in physical exercise is not lost. The student who is constantly poring over his books, while he takes but little exercise in the open air, does himself an injury. A proportionate exercise of the various organs and faculties of the body is essential to the best work of each. When the brain is constantly taxed while the other organs are left inactive, there is a loss of physical and mental strength. The physical powers are robbed of their healthy tone, the mind loses its freshness and vigor, and a morbid excitability is the result.